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Indoor Free Flight Forum => Scale, Indoor => Topic started by: TheLurker on September 02, 2019, 03:21:29 PM



Title: Junkers 87 B-2/R-2
Post by: TheLurker on September 02, 2019, 03:21:29 PM
Ladies and Gentlemen, Girls and Boys,

In a spirit of friendly competition (and in order to extract a little revenge, appendix (a)) the Board of Testwood Towers Operational Research (TTOR) has issued a challenge to the Board of The Lurker Industries Aviation Co. Ltd.

The challenge is to build a "kit scale" model of a WWII combat aeroplane whilst accruing as many penalty points as possible.  Only penalties incurred in an attempt to make the model more like the prototype will be counted.

The challenge having been made and accepted in April of this year, some effort has gone into formalising the rules of engagement which are set out below.

Rules of Engagement
The reference plan/kit will be the Keil Kraft Junior Series Ju-87 (B2) kit first produced in March 1958, a version of which is now being sold by the Vintage Model Co. of Bakewell, Derbys.

The appointed adjudicator is His Honour Baron Jack Plane.  Not only is this gentleman an highly esteemed member of the Judiciary and the German nobility he is also the Chairman of the Board of Directors of the Oxon Flugzeugwerke (Westen) GmbH and is reckoned one of the finest judges of aerial machinery currently practicing (That's more than enough crawling. Ed.)

Forfeits & Prizes
Should 15 or fewer penalty points be accrued and, or the model fail to fly for a minimum of 12s from a hand launch the Chairman of the Board of The Lurker Industries Aviation will be obliged to eat a serving of, "Smashed Avocado on Toast" appendix (b).

Should a qualifying flight time be achieved and 16 or more point penalty points also be amassed, the Chairman of the Board of The Lurker Industries Aviation will be provided with either a Black Pudding sandwich made with bread from a Plain, not Pan, loaf (appendix (c)) and butter, quite definitely not margarine, or a serving of Spam Fritter with two slices of fried bread, appendix (d).

The Chairman of the Board of TTOR may choose to award a prize additional to either of the alternatives listed should he feel that the completed model has surpassed the minimum level of acceptability by a significant margin.  Such largesse is entirely at his discretion, appendix (e).

The cost of any forfeit or prize is to be borne by Testwood Towers Operational Research.

In summary

1 - The object of the exercise is that the competitor should build a model to the Indoor Kit Scale rules whilst accumulating the maximum possible number of penalty points.

2- The only points awarded will be penalty points.

3 - Penalty points will be awarded according to the current kit scale rules, subject to rules No. 4 and No. 5

4 - If the judge considers that a particular change is detrimental to the overall character of the model, no points will be awarded for that change.

5- If the model is airbrushed, 5 penalty points will be deducted for gratuitous rule bending.

6 - The model must achieve a minimum flight time of 12s from a hand launch in the presence of an independent witness or witnesses.  If it fails to do this the forfeit must be accepted.

6.1 - Filmed evidence will be accepted as an initial proof, but it must be confirmed by flight trials in the presence of witnesses at some agreed date.

7 - Prizes will be awarded on a sliding scale, with 15 penalty points or fewer requiring the competitor to eat something that he really doesn't like, improving on a sliding scale with a more penalty points (appendix (e)).

Appendix (a) – The Revenge
Members of the parish may be aware that The Chairman of the Board of TTOR is not very good at all at not "improving" kits.  Members of the parish may also recall that the Chairman of TTOR was challenged by the entire staff of The Lurker Industries Aviation Co. Ltd. to build a kit "Straight from the Box" they being well aware of the The Chairman of TTOR's congenital inability to let well enough alone.

Abl's Stinson Build (https://www.hippocketaeronautics.com/hpa_forum/index.php?topic=23953.0)

The Chairman of TTOR, being fully cognizant of Lurker Industries Aviation's reputation throughout the industry for its distinctly unadventurous approach to aircraft design and construction, feels that it is now time that some of the pain his organisation endured should be visited upon his erstwhile tormentors by forcing said tormentors to be adventurous.

Appendix (b) – On The Awfulness of Avocado
If human beings were intended to eat sloppy green goo tasting of not very much at all we would not have been given teeth or taste-buds.  Dreadful, dreadful stuff.  An abomination.  Readers are referred to the attached picture of Green Goo on Toast.

(https://cookieandkate.com/images/2012/04/avocado-toast-recipe-3-550x824.jpg)

Observant readers will note the larding of the green goo in the picture above with lots of something, anything, to give it some sort of flavour or at least make it just about palatable.

Appendix (c) – Black Pudding & Plain Loaves
Black Pudding.  Proof comestible that all that is porcine may be used but the squeak.  When combined with salt butter and plain bread as well as a cup of Greek or other strong black coffee it is positively ambrosial.  A black pudding supper isn't all that far behind either.

Despite the risk of offending Hebrideans, Lancastrians and possibly the Germans the Chairman of Lurker Industries Aviation Ltd has stated, publicly and repeatedly, that the best Black Pudding he has ever eaten was purchased from a delicatessen in Dignes-le-Bains. However being French they called it by some daft foreign name, "Boudin noir" or some such.

Ambrosia (https://en.wikipedia.org/wiki/Black_pudding)
Staff of Life (https://en.wikipedia.org/wiki/Plain_loaf)

Appendix (d) – Spam Fritters
How can it be said that British food is terrible when such towering culinary masterpieces as the Spam Fritter can be had from even the meanest and most humble of catering establishments throughout the land?  It will be a very, very sad day indeed when we see the last of Spam Fritters.

Link for spam fritter
Making me hungry already... (http://www.bakerchristine.co.uk/spam_fritters.html)
Vital Information (https://en.wikipedia.org/wiki/Spam_fritter)

It is pleasing to note that Hawaiians (https://www.theguardian.com/lifeandstyle/2017/jul/22/spam-flavourful-as-hell-hawaii-spam-jam) amongst others also recognise Spam as one of life's pleasures.


Appendix (e) -  Rule No. 7 addendum and comment on prizes.
The Chairman of the Board of Directors of Testwood Towers Operational Research writes,  "In other words, Lurk can change what he likes as long as it's making the model look more like the real thing; rule No. 4 is there to discourage the making of gratuitous changes (non-scale lengthening of the nose) that are only done to gain penalty points, rule No. 5 is there for a similar reason and if he does a really good job (or I'm feeling sorry for the poor old fellow) then the prize would be a fry-up at either the establishment of the contestant's choice, or the Super Sausage cafe, Towcester.


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on September 02, 2019, 03:33:29 PM
Slightly more seriously, but not much...

This isn't going to be a fast build, too much other stuff going on, so I expect it'll be December before the build is finished and if previous autumn builds are any guide it'll be April of next year before any attempt is made at a maiden flight.

The intended scheme is an R-2 in Italian service that was captured by the RAF.  I stumbled over this scheme when looking for something suitable and by happy chance Airfix have used it for their B2/R2 kit so I have good colour references.

Something that amused me, that I found when digging around, was that McHard's Ju87D plan was published in Sept. 1957 and Keil Kraft's B2 appeared in March of 1958.  I rather like the idea of Keil Kraft letting AM do the leg-work of market research and then pushing out a kit knowing there'll be a demand for it. I doubt it was like that at all, but the possibility that it was tickles me.

So settle down in a comfy chair, grab some snacks, pour yourself a drink and sit back and watch me make a horlicks of it in slow time. :)

Lurk.


Title: Re: Junkers 87 B-2/R-2
Post by: Jack Plane on September 02, 2019, 04:03:02 PM
Well Lurk, for this one I've already had to pour myself a stiff single malt!

  ;D


Title: Re: Junkers 87 B-2/R-2
Post by: Andy Blackburn on September 02, 2019, 04:12:44 PM
The fact that it's taken this long and then you've done such a comprehensive job on the initial post (and have already chosen the colour scheme) is of some concern to me; it's looking suspiciously as though Lurker Industries have A Plan. It would appear that our only hope of avoiding an expensive visit to the Super Sausage Cafe is that the model somehow fails to attain the minimum flight time. Which would be a shame, but obviously less expensive...


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on September 02, 2019, 04:18:18 PM
Quote from: abl
It would appear that our only hope of avoiding an expensive visit ... fails to attain the minimum flight time.
I have just been reviewing the performance of the Company's previous aeroplanes with our test pilots and engineering staff (see the attached staff list) even with extensive use of outside consultants they barely achieved 15s. The Chairman is reported to be rather concerned about this as he really doesn't like green goo on toast.

Or ...  I think yer money's safe.  :)


Title: Re: Junkers 87 B-2/R-2
Post by: Andy Blackburn on September 02, 2019, 04:28:15 PM
Sorry, Lurk - that's a bit small and I can't read it, even in expanded mode...

...although is Neville Barnes-Norway chief designer? Nothing like having the best of both worlds...


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on September 02, 2019, 04:38:37 PM
> I can't read it, even in expanded mode...
Just as well you're not the judge eh? :)

> ...although is Neville Barnes-Norway chief designer? Nothing like having the best of both worlds...
Norville. Second cousin thrice-removed on his mother's side.


And through the magic of Inkscape ...


Title: Re: Junkers 87 B-2/R-2
Post by: LASTWOODSMAN on September 02, 2019, 05:57:11 PM
     Hi Lurker.   You made me type in "old typewriter font".   Do you really have a manual typewriter ?

LASTWOODSMAN
Richard


Title: Re: Junkers 87 B-2/R-2
Post by: Monz on September 02, 2019, 08:19:57 PM

Appendix (b) – On The Awfulness of Avocado
If human beings were intended to eat sloppy green goo tasting of not very much at all we would not have been given teeth or taste-buds.  Dreadful, dreadful stuff.  An abomination.  Readers are referred to the attached picture of Green Goo on Toast.



You've obviously never had a a properly grown and sun ripened Avocado like I used to have in Africa. So delicious! The horrible, watery and hard little green things offered in this country as 'ripe 'n ready' do the greatness of the Avocado no justice. The first things I do when I go back are get some avo, cheddar and pinotage.


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on September 03, 2019, 01:13:21 AM
Quote from: LASTWOODSMAN
Hi Lurker.   You made me type in "old typewriter font".   Do you really have a manual typewriter ?

Lurker Industries has found that the most effective way to reduce stationery costs and to effect a great saving in the wages bill for clerical staff is to have managerial and other administrative staff do their own typing on one of the company's pool typewriters.  It encourages them to think very carefully about whether or not the memorandum or other bit of bumf being considered is really necessary.

Or.... nah.  I used the "Rough Typewriter" typeface in Open Office Writer and pushed the doc. through PDF to SVG to PNG.  Yes I was bored when I did it. :)

Got rid of my portable typewriter, little East German job, brand was "Erika" IIRC, 10 or so years back.  I hadn't used it in the previous decade.

Quote from: Monz
...The first things I do when I go back are get some avo, cheddar and pinotage.
Well we can agree on the cheese and the wine, so two out of three ain't bad. :)


Title: Re: Junkers 87 B-2/R-2
Post by: Graham Banham on September 03, 2019, 02:39:39 AM
I appreciate the full industrial might of Lurker Industries is behind this project, but i can’t help but think that this one would be a better alternative at 25” span? Dave Cowell / Aerowerkes does some lovely Comet repro kits.......


Title: Re: Junkers 87 B-2/R-2
Post by: Andy Blackburn on September 03, 2019, 02:49:19 AM

...

I have just been reviewing the performance of the Company's previous aeroplanes with our test pilots and engineering staff (see the attached staff list) even with extensive use of outside consultants they barely achieved 15s.
...


Wait a minute, wait a minute! You have Bertie Wooster as a test pilot?...


Title: Re: Junkers 87 B-2/R-2
Post by: Andy Blackburn on September 03, 2019, 02:57:34 AM
I appreciate the full industrial might of Lurker Industries is behind this project, but i can’t help but think that this one would be a better alternative at 25” span? Dave Cowell / Aerowerkes does some lovely Comet repro kits.......

Lurk has already bought the kit, though (I've seen it). Wish I knew what his deviously detailed plan is, though - perhaps it's time to approach some of the members of staff to see if anyone is prepared to spill the beans.

When this was first discussed the reference was one of the Keil Kraft free flight scale kits that we used to buy in the 1970s with pocket money; it was obvious that the german models in particular were miles out (no idea what Albert E Hatful was using as his scale reference, a very early version of "Aircraft of the Fighting Powers", probably), but we were not very practiced in outline comparison in those days and in any case couldn't afford any scale drawings, so had nothing reliable to compare with.


Title: Re: Junkers 87 B-2/R-2
Post by: Russ Lister on September 03, 2019, 05:44:25 AM
My friend Stephen Fry, is puzzled.
You say that your second post is more serious, albeit it slightly.
Does this mean that you are still purposely pursuing penalty points ..... or was the purpose of posting your premier post to be purposely provocative?
Please clarify your position re. Penalty point pursuance.


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on September 03, 2019, 06:07:54 AM
Will explain when not at work.
Lurk.


Title: Re: Junkers 87 B-2/R-2
Post by: Russ Lister on September 03, 2019, 06:09:46 AM
Understandable ... and reminds me that I should already be at work!


Title: Re: Junkers 87 B-2/R-2
Post by: Pete Fardell on September 03, 2019, 07:34:35 AM
Sorry, are you saying directing Lurker Industries is not even your real job?!!


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on September 03, 2019, 12:44:28 PM
Quote from: FreeFlightModeller
Please clarify your position re. Penalty point pursuance.
A long time ago in a sports hall far, far away ....  the subject of a counter-challenge to the "Out of the Box Build" was raised and Abl thought it would be fun, for whom I am not sure, to go the other extreme and polish the kit/plan as much as possible pulling in all sorts of extras and from that arose the idea of an "anti kit scale" competition. So yes, the aim is to make the model as much like the prototype as my limited skill will allow and deviations from the kit/plan that make it look better are "rewarded" by the amassing of penalty points.  The rest of the nonsense in my opening post was just for giggles*, mine mostly, but I did hope it would make at least some of the parish smile.

Sorry, are you saying directing Lurker Industries is not even your real job?!!
Of course it's my real job.  Who could want a finer one?  I just do the other to help out and to make life more interesting.

Quote from: Graham Banham
Dave Cowell / Aerowerkes does some lovely Comet repro kits.......
Aye, but part of this game is taking a kit/plan that's not such a star and doing my best to make it better.

Quote from: abl
Wait a minute, wait a minute! You have Bertie Wooster as a test pilot?...
Indeed, but they don't give out the DFC nor a bar to it for horseplay at Drones.  Even chaps like Bertie grow up you know.  It is true he made a bit of a bish of some of the Horsa's landings but Mr. Barnes-Norway has to shoulder at least part of the blame for giving him such an awkward craft to deal with.

*Except the bit about the food, that's deadly serious.  If I make a horlicks of this I will have to eat green goo on toast.  *shudder*


Title: Re: Junkers 87 B-2/R-2
Post by: billdennis747 on September 03, 2019, 01:08:14 PM
thought it would be fun, for whom I am not sure, to go the other extreme and polish the kit/plan as much as possible pulling in all sorts of extras and from that arose the idea of an "anti kit scale" competition.
I haven´t taken much notice of this, having been preoccupied with the ruination of outdoor FF scale, but I like the idea. Will there be a prize for last? On the rare occasions I enter KS I have made half hearted attempts to come last, mainly through the utilisation of paint, but this has captured my imagination. A stsrting point might be to take a rotten kit (Pete´s Puss Moth?) -  the rottener the better (definitely Pete´s PM) -  and correct all the outlines., add more ribs. In fact build an Open Rubber Puss Moth  and enter it along with the rotten kit plan.
I´m on a roll, let me at it...


Title: Re: Junkers 87 B-2/R-2
Post by: Pete Fardell on September 03, 2019, 01:28:49 PM
Couple of queries... Will you be allowed to draw the judges’ attention to all your transgressions to ensure they don’t miss any? Also, to get the full perversity value of your self imposed rules should you have to keep all the things that are normally exempt from penalties? Eg. original peg position, kit wheels and prop.


Title: Re: Junkers 87 B-2/R-2
Post by: LASTWOODSMAN on September 03, 2019, 01:34:23 PM
         Hi Lurker.   I'm thinking of expanding my food experience.  In your opening post, two pics at the end, the first one with the Super Sausage Cafe breakfast with the egg -  it looks like a pretty hearty breakfast.   Is the Sausage what is called a "Banger"?   And what is that black burned up offering  :o  that is not reflecting any light ?   ???   Is that the famed "Haggis" ? (a Scottish dish consisting of a sheep's or calf's offal mixed with suet, oatmeal, and seasoning and boiled in a bag, traditionally one made from the animal's stomach.)

Pic of Haggis

LASTWOODSMAN
Richard


Title: Re: Junkers 87 B-2/R-2
Post by: Andy Blackburn on September 03, 2019, 02:27:53 PM
Couple of queries... Will you be allowed to draw the judges’ attention to all your transgressions to ensure they don’t miss any?

There's nothing in the rules that says Lurk can't do that. Equally, there's nothing in the rules that says that some well-meaning individual (modesty forbids, etc..) can't protest that a particular change is not significant enough to merit the award of penalty points. The final decision will rest with His Honour The Judge, of course.

Also, to get the full perversity value of your self imposed rules should you have to keep all the things that are normally exempt from penalties? Eg. original peg position, kit wheels and prop.

If I might draw the Rt Hon Gentleman's attention to the rules as outlined in post #1, it can be seen that no such restrictions exist.  :)


Title: Re: Junkers 87 B-2/R-2
Post by: billdennis747 on September 03, 2019, 02:34:56 PM
In this race to the bottom, may we employ lousy workmanship too? I have found it works in the past.


Title: Re: Junkers 87 B-2/R-2
Post by: Squirrelnet on September 03, 2019, 03:06:22 PM
I'm following this thread with great interest Lurk and hope you earn your Black Pudding

Quote
And what is that black burned up offering  Shocked  that is not reflecting any light ?   Huh   Is that the famed "Haggis" ? (a Scottish dish consisting of a sheep's or calf's offal mixed with suet, oatmeal, and seasoning and boiled in a bag, traditionally one made from the animal's stomach.)

Pic of Haggis

Black pudding is bit different Richard. It it a delicacy originating in the north of England made from pigs blood and oats (it is delicious) and also formed the chosen weapon for the ancient martial art of Ecky Thump... it was genuinely banned by my school when I was a lad.

To confuse you further here's a clip from youtube - https://www.youtube.com/watch?v=Ko0U7UjP_6g (https://www.youtube.com/watch?v=Ko0U7UjP_6g)


Title: Re: Junkers 87 B-2/R-2
Post by: Pete Fardell on September 03, 2019, 03:12:12 PM
I do like black pudding, but haggis is an altogether classier and more tasty dish. Of course, as with all these things, there's good haggis, indifferent haggis and really good haggis.


Title: Re: Junkers 87 B-2/R-2
Post by: Russ Lister on September 03, 2019, 03:15:52 PM
I shall follow your pursuit of an "anti-win" with interest  :)

You might want to try some moral turpitude.. a thinner that allows a thin coat of paint, thus fooling the judges that yours is a tissue finish .... much frowned upon if they find it though .... penalty points will roll ::)


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on September 03, 2019, 04:39:09 PM
Well as Abl has guessed I do have a plan, whether or not it is cunning remains to be seen.

Finish.  I'm going to try for an all tissue finish.  The camouflage is splinter so it's straight edges, this will help.  I will also be giving EzeDope a miss for this build.  It worked OK for applying the cheatlines and small detail on the M-10, but on domestic tissue it was an absolute B to use on the large fin bands.  I've found some pretty good matches for the base colours, Abl kindly tacked the "Hell Blau" for me onto an order of bits from the States, my but that was pricey tissue.  The other two tissues came from VMC.  See the pics.  Covering is the bit I'm most likely to utterly foul up, but I'll worry about it when I get there.  I'll probably have to do most of the "decals" with 45gsm, but if I'm not pushed for time I'll see what I can do with cut tissue.  After all it is, sort of, a kit scale build.

Herewith the first deviation.  Older readers may remember that Keil Kraft's less expensive kits came with sheet empennages.  Well this one won't.  At the moment I'm swithering on stab. span.  It'll probably be 110% of scale.  There will also be a small amount of lamination, mainly to get a good curve on the top of the rudder.  The plan is also to hinge the rudder.  This proved enormously helpful on the Lacey M-10; enough for me to think it worthwhile adopting it as routine practice.

Quote from: billdennis747
In this race to the bottom, may we employ lousy workmanship too? I have found it works in the past.
Alas Bill, I'm so ham-handed I won't have to try on that front.

Quote from: Pete Fardell
Will you be allowed to draw the judges’ attention to all your transgressions to ensure they don’t miss any?
Oh dear me no, that would be boasting, really most ungentlemanly, quite unseemly and one does not argue with the umpire.  Just not cricket.  If I have to endure the forfeit through an oversight of His Honour then I must do so with good grace ... and a sick bag to hand.

Quote from: Pete Fardell
I do like black pudding, but haggis is an altogether classier and more tasty dish. Of course, as with all these things, there's good haggis, indifferent haggis and really good haggis.
You had to say that just as supper time was coming up didn't you?  Where am I going to get haggis at this time of night? 
*Ancient history.   You may tune out now*  When I was a penniless student oaf a very long time ago I lived within easy walking distance of Bruntsfield where MacSweens had their shop.  Now that was really good haggis.

Quote from: FreeFlightModeller
You might want to try some moral turpitude..
Alas I fear that would be classified with, "Using an airbrush with intent." and be frowned upon most severely by the adjudicator and cost me many, many penalty points which I can ill afford to lose. :)


Title: Re: Junkers 87 B-2/R-2
Post by: Andy Blackburn on September 04, 2019, 02:04:29 AM
Oh dear.

Replacing all-sheet tail surfaces with built-up equivalents is at least two "significant deviations" (and I can see how it might be more than that) and if it goes on like this you're going to walk it. I'd better go and break open the piggy bank.


Title: Re: Junkers 87 B-2/R-2
Post by: yagua on September 04, 2019, 07:30:51 AM
Soo.... if I get it right, the thing is to use a not very good plan and build as much as "perfectly scale" possible..?

Appendix (b) – On The Awfulness of Avocado
If human beings were intended to eat sloppy green goo tasting of not very much at all we would not have been given teeth or taste-buds.  Dreadful, dreadful stuff.  An abomination.  Readers are referred to the attached picture of Green Goo on Toast.



You've obviously never had a a properly grown and sun ripened Avocado like I used to have in Africa. So delicious! The horrible, watery and hard little green things offered in this country as 'ripe 'n ready' do the greatness of the Avocado no justice. The first things I do when I go back are get some avo, cheddar and pinotage.
Definitely!! I have a couple of avocado trees at home, and they should be eaten when they fall. It´s the exact maturation point. Also try it smashed, with some salt and (no too many) lemon drops. Perfect company for a steak ;D
PS: When you buy it, if the shell is not firm (flimsy), it´s a little bit on the rotten side. If it´s too firm (hard), is not mature enough. In this case, wrap it with brown paper or newspaper and leave it for a couple of days in a mid temperature not sunny place (not fridge, not too hot)
PS2: I´m allready drooling..!!  ::)


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on September 04, 2019, 02:03:57 PM
Quote from: abl
... if it goes on like this you're going to walk it.
Don't forget those final 12 seconds.  If the build fails up at any point up to and including that qualifying flight I lose. :)

Quote from: yagua
Soo.... if I get it right, the thing is to use a not very good plan and build as much as "perfectly scale" possible..?
Partly.  There's a few bells and whistles to make the whole enterprise more amusing, but it's not a bad way of thinking of it.

As for Monz' and your joint advocacy of avocados.  It may be that a perfectly ripe avocado is delicious and that my opinion of the edibility of the same has been biased by the poor quality of those available in these benighted islands, but any foodstuff that has such a narrow window where it is fit to eat is automatically suspect in my book.  You'll be telling me next that medlars are delicious too.  :)


Title: Re: Junkers 87 B-2/R-2
Post by: Russ Lister on September 04, 2019, 03:51:04 PM
Are we not walking the tightrope between adherence to plan .... and straight DQ? If it is too far from the plan and kit, it may just be declared "not a kit scale model"?

Party Pooper.


Title: Re: Junkers 87 B-2/R-2
Post by: Andy Blackburn on September 04, 2019, 04:22:44 PM
I don't think so, because:

a) There's nothing in the rules that were outlined in the first post to that effect, and
b) There doesn't seem to be anything in the "Normal" kit Scale rules about a model being disqualified for having too many changes - just dark threats about "significant deviations" costing 5 points.

This is very handy because one of my personal ambitions is to present a model for kit scale judging that looks like a real aeroplane but which manages to score 0 or fewer static points because of all the penalties; unfortunately I haven't worked out how to do this yet - I think I can get to somewhere near 50 penalty points by selecting the correct kit and then fixing all the scale deviations, but that's not really enough.

Of course, the powers that be might now add a "disqualification" clause but that would be most unsporting...



Title: Re: Junkers 87 B-2/R-2
Post by: Russ Lister on September 04, 2019, 04:39:32 PM
Yes Andy, it would be a shame to introduce such a clause .... I feel miserable just voicing the possibility!


Title: Re: Junkers 87 B-2/R-2
Post by: applehoney on September 04, 2019, 06:44:54 PM
"present a model for kit scale judging that looks like a real aeroplane but which manages to score 0 or fewer static points "

Not kit scale ... but back in the 60's I had a 'scale' model tossed out of an event at an Elvington rally.  Tried to enter a TD.049 pylon model, to be told it was a scale event for models that looked like a real airplane.  I brought out a large version of the design with a honking .40 up front.   Pointed out that it was a real airplane as I could hold it in my hand ... that the1/2A was same design, same structure, same colour scheme  ...and was therefore a scale model of the real one.  Then had the pleasure of pointing out that their club rules did not specify that an entry had to be of a man-carrying airplane. Judge was taken aback .... vocal assessment caused some general amusement.  Anyone in ye olde countrie remember Sam Messom ?


Title: Re: Junkers 87 B-2/R-2
Post by: billdennis747 on September 05, 2019, 02:37:04 AM
  Anyone in ye olde countrie remember Sam Messom ?
No but I clearly remember his photo in his obituary in AM in the 60s. He looked the kind of old-school bloke who would give up his Sunday to run an event for the enjoyment of others.


Title: Re: Junkers 87 B-2/R-2
Post by: Andy Blackburn on September 05, 2019, 02:51:16 AM

Then had the pleasure of pointing out that their club rules did not specify that an entry had to be of a man-carrying airplane. Judge was taken aback .... vocal assessment caused some general amusement...


 ;D

That story has made my day.

A.


Title: Re: Junkers 87 B-2/R-2
Post by: John Webster on September 05, 2019, 03:03:33 AM
One wonders why a forward thinking firm like Lurker Industries has a farrier and cartwright on staff.


Title: Re: Junkers 87 B-2/R-2
Post by: Jack Plane on September 05, 2019, 04:20:47 AM
One wonders why a forward thinking firm like Lurker Industries has a farrier and cartwright on staff.

Maybe Lurker Industries is in fact planning for all future UK scenarios...?!  ;D


Title: Re: Junkers 87 B-2/R-2
Post by: kkphantom on September 05, 2019, 04:25:16 AM
One wonders why a forward thinking firm like Lurker Industries has a farrier and cartwright on staff.
Well you wouldn't expect the company secretary to shoe the horses or fix a broken cartwheel, would you?


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on September 05, 2019, 05:47:37 AM
One wonders why a forward thinking firm like Lurker Industries has a farrier and cartwright on staff.
A horse and cart can go where a motor vehicle cannot.  Always a consideration when recovering personnel from *cough* unplanned landings.


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on September 07, 2019, 04:33:51 AM
Aircraft production work is currently suspended whilst the Works Dept. puts a number of issues right with the Company's buildings including the Assembly Shed. However administrative work continues and The Board wishes to thank Mr. Webster, a correspondent outwith the Empire, for his enquiry about Mr. Worcester's career. It is hoped that the following information will be helpful.



Fortunately, or perhaps more accurately unfortunately, Mr. Worcester's early adult life has been rather too well documented by Mr. Wodehouse.  Almost all of Mr. Wodehouse's work, including his biographies of Mr. Worcester, can be obtained in a number of formats, including plain text, and without cost from Project Gutenberg (http://www.gutenberg.org). Some of the more popular biographies are listed below.

Right Ho, Jeeves (http://www.gutenberg.org/ebooks/26303)
The Inimitable Jeeves (http://www.gutenberg.org/ebooks/59254)
My Man Jeeves (http://www.gutenberg.org/ebooks/8164)

Given Mr. Worcester's subsequent career, one can only remark that the remarks attributed to His Late Majesty King Henry the Fifth, by a Mr. Wm. Shakespeare, a most unreliable biographer by all accounts, apply most aptly to Mr. Worcester,

   "How he comes o'er us with our wilder days,
    Not measuring what use we made of them."



Or ...  
Still tied up with redecorating bits of the house so only niff, naff and trivia around the edges of this build are getting done at the moment.

Lurk



Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on October 05, 2019, 04:13:57 PM
Despite complaints from a number of members of staff about the lingering reek of paint in various parts of the Company premises work was resumed a week ago following the autumn fair fortnight shutdown.

Or...

Bulk of fuselage done.  So what's been changed?  Ohh, not a great deal.  Let me see now . . .

Front end has had to be significantly reworked.  The most obvious kit deviation from the prototype is the top line of the nose.  The kit is a smooth line from cockpit to prop. whereas the prototype has an asymmetric air intake which is sort of flat.  The underside isn't quite right either.  The kit fuselage line is more like a Hurricane or Spitfire.  A gentle curve from the LE up to the prop.  Whereas the prototype is flattish under the cockpit angling down roughly 15 to 20 deg from the LE to the back of the rad. housing and quite sharply angled up after the rad housing to the prop.  Oh and the rad. housing on the kit wasn't quite deep enough and flat bottomed rather than rounded.  Umm what else?  Weel.... the proportion of the rear part of the fuselage isn't quite right either, so, that had to be ermm tinkered with.

As I was rejigging the front end I've decided to go for a removeable noseblock because the kit setup looks like it's only really suitable for hand winding.  Which, given the kit's original target market, is fair enough.  The removeable noseblock also makes it easier to represent the prototype's lines a little more closely.  

And just for fun I'm going to try representing the bomb aiming window with an inset "tent".  One side pale blue the other silver or something that suggests reflective glass.

What's left to do?

Strip and replace F3-F6 stbd short lower with something a little less like an oak roof beam.  
Cut and fit the rad. inlet and final stringers
Fit motor peg panels
Infill over the top between F1 & F2 and a fillet for the asymmetric inlet shape.
Some infill to support the exhaust stacks.
Probably some infill over the top of the nose.


Lurk.


Title: Re: Junkers 87 B-2/R-2
Post by: Andy Blackburn on October 05, 2019, 05:31:01 PM
> Front end has had to be significantly reworked.

Look on the bright side - that's got to be at least 5 and possibly 10 penalty points...  :)

Watching with great interest.

A.


Title: Re: Junkers 87 B-2/R-2
Post by: Russ Lister on October 06, 2019, 01:34:43 PM
Änderung verboten  ;)


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on October 06, 2019, 03:52:58 PM
Quote from: FreeFlightModeller
Änderung verboten  ;)
I've started, so I'll finish... :)

So much for plans.  Got the "beam" replaced, motor peg panels in and the rad. housing is started.  Unfortunately the radiator grille looks more like a cheesy grin than a rad.  and it's not quite symmetrical.  Bother.  Rivet counters will also note that it isn't as deep as it should be for scale accuracy. Partly the limits of the material, the presence of the lower keel and the builder's limitations.

The construction is a very simple.   A 1/32" ply reinforcer cut, pierced and glued behind F1 which is then pierced.  The bottom 4 stringers are cut deep and curved outwards.  The plan is to infill with soft 3/32" and shape to match these curved stringers so that I can represent the belling out of the housing on the prototype.   

The bottom keel within the housing will be extended to the bottom of the housing and initially the gap won't be filled.  Plan is to leave the space between the inner stringers and the keel open so that main ballast can be glued to the extension.  It may get filled in after that, it may not.  We'll see.


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on October 07, 2019, 07:26:04 AM
Quote from: TheLurker
... Plan is to leave the space between the inner stringers and the keel open so that main ballast can be glued to the extension.  It may get filled in after that, it may not.  We'll see.
Change of plan.  Nice big noseblock opening with lots of clearance for fingers (well tweezers) so mount platform above lower keel between F1 & F2. Stick initial ballast to that. Will also do for flight trimming ballast as well.  Much neater. Amazing what a few hours kip can do eh?


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on October 07, 2019, 04:20:37 PM
Oh dear, yet more letters from the various Ministries wanting to know why production so slow at Lurker Industries....

Plodding on.  Four, count em, four!, bits of infill fitted tonight and the air intake rough shaped.   The profile of the air intake will have to wait for the nose-block before final sanding to get the line, but it looks about right at the moment.  Unless I have a massive brain-wave as to how to represent the intake shape of the port side moderately well I'm going to leave the top port side of the nose flat.


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on October 12, 2019, 04:08:52 PM
Fuselage, nearly, done.  Have to make up the nose-block to before I finish shaping the line of the air intake, but it's close enough to be worth showing progress so far.  Only taken a fortnight. :)

I'm calling the rad housing a score draw. The modification for the rad. intake would have worked better with a 1/64" ply reinforcement rather than 1/32", the 1/32" is too hard to work easily in a fragile area.  However the "chin" has worked pretty well and the overall profile is now very definitely Ju87 rather than a "probable" Ju87.  I'll probably stick a rad. image over the top of the pierced intake when it's transferred to the paint shop because I'm not sure I can live with the asymmetry.  The rear part of the rad housing will, probably, be made, in accordance with the kit suggestion, out of card although.... 

For those trying to keep track the kit housing was a bolt-on, card-covered, not deep enough and flat bottomed into the bargain. It's now is incorporated into the formers and is closer to scale depth.

Another deviation from the kit.  Nose is part sheeted. Why?  Werl... Did it for K5083 (VMC Hurricane) and it gave a much better finish over complex nose curves and the top of the Ju 87's nose looked to me like it'd be worth doing for much the same reason.  The rest of the fuselage is surprisingly slab-sided so (one hopes) it'll be a relatively straight-forward covering job.

Oh, yes.  Another change.  The way the wings are fitted.  I'll explain why later in the build when I get to the wings.  Nothing to do with appearance.

Just out of interest.  Am I alone in taking such an awfully long time to fit infill?  It can take me anywhere from 10 minutes to half an hour to get a panel in place and that's if I get it right first time.
 
Pics.  Couple of close-ups of the rad. housing one showing that damned off-centre grille and the rest general views of the fuselage as it is now.


Title: Re: Junkers 87 B-2/R-2
Post by: Crabby on October 12, 2019, 05:41:58 PM
Hi Lurk. I was dreading all the nose infill I had to do on my Rockytop Spitfire, so much that I even dreamt up a solution. What I did in the end was wrap the nose in white tissue and did a full nose pencil rubbing. When the tissue was removed and mounted flat onto 1/16 sheet, I had a perfect pattern from which to cut, and more important it made sense to me. I waited a long time to get this idea to float in, and the build was in a state of revolving hour glass till it appeared in a dream state one night. I get stuck a lot like this, and a build can sit for months till the answer comes. So no I don't think you take too long at all on your builds. Unless there is a time clock next to the door of your hobby space!


Title: Re: Junkers 87 B-2/R-2
Post by: MKelly on October 12, 2019, 08:41:52 PM
Lurk,

I've used Crabby's tissue technique to size infill with good results, also have wrapped masking tape over the desired area, trimmed along stringer and former edges and used the tape cutout as a pattern for the infill piece.  A marginally faster approach was to cut a sheet of balsa crossgrain the width of the space between formers.  Once the width is a nice snug fit between the formers you can just hold it up to the bay you're about to infill with the edge of the sheet butted up against one stringer from the bay, trim that edge if required to match the angle of the stringer, then mark the points where the opposite stringer hits the sheet.  Trim off according to the marks, check the fit and sand if necessary to fine-tune, then glue it in.  With this approach I can infill a cowl area in an hour or so.

Enjoying watching you finagle the Stuka into shape!

Cheers,

Mike


Title: Re: Junkers 87 B-2/R-2
Post by: flydean1 on October 12, 2019, 09:36:48 PM
Another tape to use is drafting tape, the beige color like masking tape, but less sticky.


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on October 13, 2019, 03:56:26 AM
Crabby, Mike, Flydean

Thanks gents, the help is appreciated.  I already use the tissue "brass rubbing" trick, but the tape variation - Flydean's low tack suggestion is noted with interest - is new to me.    It's the sanding to exact fit, especially the chamfering of the edges that lie along the stringer that takes me the time.  Next time around I'll give Mike's x-grain cut approach a go.  Even if I can't knock the time down to as little as an hour it'd be very helpful to make the process a little faster as the nose on the 87 took me somewhere between 3 and 4 hours for 18 panels.

Cheers,
Lurk.


Title: Re: Junkers 87 B-2/R-2
Post by: billdennis747 on October 13, 2019, 04:32:57 AM
Just out of interest.  Am I alone in taking such an awfully long time to fit infill?  It can take me anywhere from 10 minutes to half an hour to get a panel in place and that's if I get it right first time.
 
I can do it pretty quickly. The trick is to do it badly then use lightweight filler and paint. Of course it doesn't work if you are covering for a tissue finish like Mike!


Title: Re: Junkers 87 B-2/R-2
Post by: Crabby on October 13, 2019, 10:01:20 AM
Fiddlesticks Lurk! what's the big rush all about? You have the old sharpened ax hanging overhead? Play some soft piccolo music, and fiddle along with it on your Stuka.


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on October 13, 2019, 03:06:28 PM
As the result of certain errors in construction The Directors have asked that Mr. Stewart (Foreman of the Assembly Shed) arrange lessons in basic numeracy for some members of staff in his Dept.  at the District Mechanics' Institute.

Or ...

When laminating parts remember that part order is n, n+1, n+2 and not n, n+2, n+1.  Even better, remember this before parts n & n+2 are glued together. Idiot.

Quote from: Crabby
Fiddlesticks Lurk! what's the big rush all about? You have the old sharpened ax hanging overhead?

No especial rush, but like most working bods, time for games is limited and the list of plans and kits that I want to get done is not getting shorter and if there are no axes to concentrate the mind there's always the scythe.  :)

Quote from: Crabby
Play some soft piccolo music...
Are you looking over my shoulder as I work!?  The pictured disc* has been one of a number on the gramophone whilst I've been working playing this weekend.

Lurk

*UK readers may be amused to note that that LP is on the SAGA** label.  All too appropriate no?
**No connection I'm sure, but an amusing coincidence nonetheless.


Title: Re: Junkers 87 B-2/R-2
Post by: Andy Blackburn on October 13, 2019, 03:48:12 PM
...Another deviation from the kit.  Nose is part sheeted.

I have instructed my legal team to argue that this does not constitute a "significant" changes and should not, therefore, attract points...  :)

...Just out of interest.  Am I alone in taking such an awfully long time to fit infill?  It can take me anywhere from 10 minutes to half an hour to get a panel in place and that's if I get it right first time.

I use the method outlined by Mike above ("...cut a sheet of balsa crossgrain the width of the space between formers...") and I think it's reasonably quick, with practice. But it does rely on the formers being square to the keel.

Just out of interest.  Am I alone in taking such an awfully long time to fit infill?  It can take me anywhere from 10 minutes to half an hour to get a panel in place and that's if I get it right first time.
 
I can do it pretty quickly. The trick is to do it badly then use lightweight filler and paint. Of course it doesn't work if you are covering for a tissue finish like Mike!

You're OK with a tissue finish if you use either a) balsa-tinted filler (which is what I do) or just add a bit of acrylic paint to the white filler. And then, of course, if anyone mentions it you act outraged without actually denying anything.


Title: Re: Junkers 87 B-2/R-2
Post by: flydean1 on October 13, 2019, 07:59:50 PM
Recorder??? Looks like what we called a flute-a-phone.


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on October 14, 2019, 07:50:52 AM
Quote from: flydean1
Recorder???
Quite possibly more than you could ever want to know about the Recorder. (https://en.wikipedia.org/wiki/Recorder_(musical_instrument))  Never let it be said that The Lurker Industries Aviation Co. Ltd. is not firmly committed to its wider educational and cultural responsibilities.  :)


Title: Re: Junkers 87 B-2/R-2
Post by: Pete Fardell on October 14, 2019, 09:33:04 AM
There's the screech of fingernails on a blackboard, there's the eardrum piercing whine of feedback from a dodgy PA system, and then there's the screams of a thousand tormented souls being roasted in the fiery pits of Hell. Sweet music, all of them, compared to the terrifying sound of...

...thirty primary aged school kids trying to play 'Go Tell Aunt Nancy' on slightly out-of-tune descant recorders. *shudder*


Title: Re: Junkers 87 B-2/R-2
Post by: Pete Fardell on October 14, 2019, 09:48:14 AM
...thirty primary aged school kids trying to play 'Go Tell Aunt Nancy' on slightly out-of-tune descant recorders.
Which, funnily enough (and to get back on topic), was of course the inspiration behind the Stuka's infamous siren.


Title: Re: Junkers 87 B-2/R-2
Post by: flydean1 on October 14, 2019, 11:37:33 AM
Most I remember was in 6th grade.  The band director from the local Middle School conducted a music class using flute-a-phones made of some sort of black plastic.  Probably he was looking for band prospects.  I distinctly remember having some sort of reaction to the plastic in that after about 30 minutes, my lips started to go numb.  Other classmates reported the same.

To this day, I can play a radio, and that's about it.

Now back to your regularly scheduled Forum.


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on October 14, 2019, 12:54:18 PM
Quote from: abl
Quote from: TheLurker
...Another deviation from the kit.  Nose is part sheeted.

I have instructed my legal team to argue that this does not constitute a "significant" changes and should not, therefore, attract points...  :)

The Lurker Industries Aviation Co. Ltd. legal representatives, Messrs Grasping, Lyre, & Cheetham (Attorneys at Law, Public Notaries & Commissioners for Oaths) have received instructions from the Company's Drawing Office in the person of Mr. Barnes-Norway to contest this.  The Drawing Office maintains that no-where in the original design is any reference made to any means of sheeting by infill on any part of the main fuselage surface. The use of tissue covered card to cover the area around the tail-wheel is not considered by the Drawing Office to be sufficiently like infill to be classed as prior art as it uses both different material and construction techniques and is used primarily as a means of covering an area lacking stringers or other structural members which could not be covered by tissue alone unlike the nose which could be so covered.  Mr. Barnes-Norway and his team therefore feel that use of sheet infill is an entirely novel and therefore significant amendment to this particular design.  Mr. Barnes-Norway also said, "Yar boo sucks!", but that was after his second sherry and it may be that he will inclined to apologise unreservedly for this remark when he has *ahem* recovered his composure.


In other news.  Work continues v. slowly on the nose-block.

Cheers,
Lurk.

P.S.  Pete, be afraid, be very, very afraid.  I still have my Selmer Descant Recorder.  It's so old ermm, gosh it's nearly 50, that it's made of wood and I bet even now that I can make any class of primary school kids sound like world class virtuosi.  :)


Title: Re: Junkers 87 B-2/R-2
Post by: Andy Blackburn on October 14, 2019, 05:22:03 PM

...Mr. Barnes-Norway and his team therefore feel that use of sheet infill is an entirely novel and therefore significant amendment to this particular design.


Mr Barnes-Norway will no doubt be aware that according to the OED, "Significant" is defined as "Sufficiently great or important to be worthy of attention"; a "significant" change would surely be (for example) a noticeable change to the profile of one of the flying surfaces which falls outside the variation expected during normal construction work. This particular - minor - change is hardly visible under most viewing conditions, once the model is finished.

Surely, then, considered within the ambit of the finished article, it must be obvious to m'learned friend that the addition of a few minor and hardly noticeable areas of local strengthening in an area where handling is inevitable can hardly be considered to be "important" or "worthy of attention". One has to look very hard indeed to see it at all!




Title: Re: Junkers 87 B-2/R-2
Post by: OZPAF on October 14, 2019, 10:58:34 PM
Barnes-Norway? He must have had 2 fathers with impeccable Aero design capabilities! :)

John


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on October 16, 2019, 03:30:35 PM
Quote from: OZPAF
Barnes-Norway? He must have had 2 fathers with impeccable Aero design capabilities! :)
John

Reply No. 5, Page 1. :)

Well I think this looks like a moderately good representation of the front end of a Berthe.  Not great, wouldn't claim that, but definitely recognisable without squinting too hard.

Unfortunately some filler will be required, but I was expecting this especially around the formers so I'm not going to weep over it.  If I were able to drill holes true in block I would have cut the nose-block from a single piece of wood; unfortunately I can't so I opted for laminated construction.

Pics.
Top of nose with part from an Airfix 1/72 Ju 87 B2/R2 kit (A03089) for comparison, port & stbd views and one from the front.  That awful radiator is going to be covered with a stick on "decal" come covering.

The air intake "shoulder" should project onto the nose-block, but that detail is sacrificed for practicality as is the port side "shoulder".


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on October 19, 2019, 05:39:32 PM
In a previous post I promised to explain what's going on with the wings and this is as good a point as any.

The kit has the wings mounted on a single ply beam pushed into a transverse slot/socket in the fuselage. This beam also serves as the mounting point for the main UC legs. The problem I have with this is that it offers no easy way of covering the wing prior to mating it to the fuselage.  In fact the kit instructions leave covering of the wings until after they are fitted to the fuselage (and the UC likewise fitted to the wing) and require thin strips of postcard to be attached to the edges of the root ribs to serve as tissue attachment points to allow for this. I cannot see me ever getting warp free wings this way or even a half-way acceptable finish to the tissue.

So the following changes are made. 

1.  The UC legs now have a 1/32" ply core which plugs into a socket in the outer section of the wing.  See pic.

2.  The wings now have separate tongues, basically the kit beam cut at the mid-point, fitting into a new wing box on the appropriate former.  You'll see this on the side views of the fuselage in previous posts.

This means the wing can now be covered and, this is the reason for the shenanigans, pinned to a board while the tissue is shrunk and doped. The UC legs can then be glued and plugged in the sockets fitted and the warp free (one can hope) wings can be plugged into the fuselage. The ply tongues should provide enough support on their own, but, if you look back, you'll see that there's some sheet infill that the root rib can be glued to.  Just to be on the safe side.  :)

Why the explanation now?

This change to construction imposes some changes on the build sequence. To be able to test fit bits and be sure that they all align correctly the main UC legs and fuselage have to be built before the wing. This in turn means that that the wheels have to be built much earlier in the programme than is customary.  Which is what I've been doing today.

Build the wheels?  Ahhh... yes. This brings us to another deviation from the kit. The kit wheels aren't at all bad as these things go, but they are undersize and we need want wheels that are closer to scale diameter. Unfortunately neither kit nor built wheels are the correct scale width. To be able to fit scale width wheels you'd need to vacuum form or plunge mould the spats as the laminated sheet technique that is used cannot, for the sake of robustness, give the very thin spat side walls that scale width wheels would require. Never mind, it is kit scale after all.

The other change is to the way the wheel is mounted, see the pic.  The kit instructions require a U shaped bit of wire glued and pushed into the body of the UC leg.  This change also imposes some changes on the detail of the leg construction, but unless anyone's particularly interested I won't bore you with them.

Lurk


Title: Re: Junkers 87 B-2/R-2
Post by: Andy Blackburn on October 20, 2019, 12:35:07 PM

> Build the wheels?  Ahhh... yes. This brings us to another deviation from the kit...

Luckily, wheels are free according to the rules and they can't do you for making new ones. Oh, wait, you want the points... :)


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on October 20, 2019, 02:45:48 PM
> Build the wheels?  Ahhh... yes. This brings us to another deviation from the kit...
>>Luckily, wheels are free according to the rules and they can't do you for making new ones. Oh, wait, you want the points... :)

Points for the wheels?  Nahhh.  They're an utterly trivial deviation, but they're part of the general rejigging of the UC and wing fitting.


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on October 21, 2019, 03:51:27 PM
The Board of Directors are seriously considering moving to piece work contracts as the current rate of production leaves a very great deal to be desired.

Or ...

This evening saw two wheel axles fitted, one wheel wire bent up and glued in place.  There's not much clearance for the wheel, see pics, so it's not a job to rush.   A December finish ? Aye next year. :)

Lurk.


Title: Re: Junkers 87 B-2/R-2
Post by: ZK-AUD on October 21, 2019, 04:46:43 PM
I may have got to this party too late

I used a variation on your wheel spat theme on the little KK Lysander but  with a different positioning of the wire to provide better shock absorption - you can see this at reply #25.  This has proved to work really well in service

https://www.hippocketaeronautics.com/hpa_forum/index.php?topic=24003.25 


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on October 22, 2019, 02:42:19 PM
Quote from: ZK-AUD
I may have got to this party too late...
And you forgot to bring the sherry.  :)

I saw that at the time and was very impressed by it but even though I had the idea ready to steal - and I considered it - I decided to play safe and go with something I knew that I could build.


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on October 24, 2019, 03:42:46 PM
Plodding along.

Wheels painted, core of one leg built - see pics.  Pleased that the leading edge of the wheel cover has held up, was worried it might not.  Likewise pleased that the wheel is not far off centrally aligned.  Just the outer spat sheets to affix next then the really difficult bit; sanding everything to the correct profile.   


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on October 26, 2019, 12:52:07 PM
If you want to see wheels done properly, go to ZK-AUD's Big Lizzie (https://www.hippocketaeronautics.com/hpa_forum/index.php?topic=21366.msg249523#msg249523) build thread and marvel.

Meanwhile; here in the "B" stream the first leg has turned out moderately well.  Still need to do a bit more fine shaping to the top, rear of the spat, as it's a little on the fat side but I'll leave that until I've got the second leg done.  No sense in overcooking it at this point.

I doubt readers will be surprised to find that it took me nearly as long to make up the sanding sticks and profile gauges as it did to shape the leg. With luck the second leg will now take a day or two less to build than the first now I've got a reasonably good feel for the fiddlier steps in the assembly.

Lurk.


Title: Re: Junkers 87 B-2/R-2
Post by: Squirrelnet on October 26, 2019, 01:03:22 PM
Looking good Lurk. I have a Guillows Stuka half built but the undercarriage and lack of strength in the kit version put me off. Your ply doubler is a great idea and should solve the problem . Also I like your range of sanding sticks, I'm inspired to make up some more myself. 

Chris


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on November 03, 2019, 03:47:00 PM

Quote from: Squirrelnet
... ply doubler ... should solve the problem
A thoroughly unoriginal idea, but I'm more than happy to take any credit there may be if it does help. :D  Any chance we can see some pictures of your Ju87?

As for the Lurker Industries example, it marches very slowly.  Second main leg done last night.  Looks the same as the 1st - which is a bit of a relief -  so won't waste electrons or your time on another picture.

Finally got started on the deviant, oooh no... stop messing about missus, empennage. So far.... one rudder waiting hinges. Fin and stab. to be done as / if time allows this week.

The rudder is a mix of wood.  Medium for the rudder LE - to take the hinges - and soft for the remaining 1/16" bits. The 1/32" is probably medium, it was all that the stores wallah had to hand and one doesn't want to upset him unnecessarily :) .  This component was more like a peanut build than KS.  Lots of tweezer work and the gussets were just a wee bit on the fiddly side - but I was expecting that.

Today's lesson.  Dunking 1/32" x 1/16" strip in a mug of boiling water for a couple of minutes will soften it quite well, but not quite well enough that you don't get creases on a tight curve.



Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on November 07, 2019, 03:04:39 PM
Huzzah.  A fin & rudder.

The hinges are some lovely thin tin-foil from a supermarket (Sainsbury's for - southerly - Englandlandshire based readers) quiche base. It comes in at about 115g/m2.  Not many years ago you could have used the foil casing from most pies to repair the bodywork on a car so, "Huzzah! for cost-cutting measures" say I.  I daresay most own-brand pies and quiches have similarly thin tin-foil bases these days.

In lieu of cigarette papers the rudder/fin spacing was set using three layers of 80gsm glued together, the top spacer was 2 layers and the spacer for the stab. slot is 1/16" + 4 layers of 80gsm.  The stab. spacing may be a bit too much, but I wanted to allow for a couple of layers of tissue over the 1/16" framework.  If needs be I can always pack the slot if it is too deep.

Will be covered with pre-shrunk & doped tissue. Used this construction on my Peck M-10 and it worked pretty well.

Pics.  Finished article and a couple of in-progress shots showing spacers in situ.


Title: Re: Junkers 87 B-2/R-2
Post by: Andy Blackburn on November 07, 2019, 05:21:29 PM
So, let's see... that's 5 points for converting a sheet fin/rudder to built-up construction, and at least 1 point for having a moveable rudder. I've said this before, but I have an uncomfortable feeling that this is going to cost me...


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on November 09, 2019, 04:13:01 AM
... and a stabilizer.  

Mr Barnes-Norway is preening himself on having implemented his wizard wheeze of making the final fuselage formers ever so slightly overlong at the top so as to provide a key for the fin.  The rest of the staff in the drawing office think he's too far too full of himself over such a trivial idea and are wandering around muttering about pride going before a fall.

That's the sheet tail dealt with.  Not sure whether to deal with the canopy or the wings next as both will be slightly different to the kit supplied bits.  The canopy will be plunge moulded.  No, I'll rephrase that.  I'm going to try to plunge mould the canopy.  Not having used the technique before the result could prove amusing.

The plan is to make the canopy plug from laminations, see the attachment, for three reasons. One, I guard my stock of block jealously. Two, I'm rubbish at carving and three, the canopy has three distinct sections.  It has been pointed out by the CD that this could result in some unsightly lines on the resulting canopy.  However I think it's worth the experiment as I can always fall back to a three-section plug if it all goes horribly awry.

The wing?  Well it looks like we need a complete new wing.  The image shows what I intend to build compared with the kit version.  The planned wing is a closer, although not exact, match to the prototype's proportions.  The inner, anhedral, section also changes slightly, but the differences are not so marked.


Title: Re: Junkers 87 B-2/R-2
Post by: Andy Blackburn on November 09, 2019, 09:36:08 AM

>  It has been pointed out by the CD that this could result in some unsightly lines on the resulting canopy...

They might not be too bad if you use balsa cement and clamp the joint to reduce the glue thickness to a bare minimum.

A.

P.S. is there anything on this build that you've not changed from the original plan?  :)  I think you've safely exceeded the points required for the full Monte breakfast, as long as it flies for at least 12 seconds.


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on November 09, 2019, 01:10:58 PM
Quote from: abl
P.S. is there anything on this build that you've not changed from the original plan?  :)
A number of Lurker Industries' inter-departmental memoranda have surfaced.  Two of them may shed some light on the situation.


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on November 23, 2019, 02:02:43 PM
It has been remarked upon in the Drawing Office that there is a regrettable tendency to molly-coddle pilots these days with unnecessary and weighty luxuries such as enclosed cockpits.  The elder of the McPhail brothers, James, is particularly irked by the extra weight incurred , but he is regarded as rather too purist even by the exacting standards of the rest of the staff in the Office and he refuses to be persuaded that there are aerodynamic advantages to a well designed canopy.  It is probably as well that he is considering retiring.

Or...
First experiment with plunge moulding the canopy today.  Not a roaring success, but there are grounds for optimism.

In brief.
Some evidence of lines, but they're very faint and a bit more polishing of the plug should deal with that.  If I were better at shaping block it's not a technique I'd use again as it's rather time consuming.

May have to exaggerate the steps at the front and rear sections of the plug to get a crisper step in the moulded canopy, see the profile pic.  Suspect that wouldn't be an issue with vac. forming.

Gun "bubble" works better than I thought it would. Again I suspect vac. forming is what's really needed to pull the material tight to the plug, but there's definitely a bubble.

Need to cut a proper mounting plate for the blank, the test today was with a rough cut bit of hard-board to see if a hot-air paint stripper would be a good enough heat source.  It is.  I think I may need a bigger gap around the plug as I got a very uneven draw of the sheet.  One side and parts of the top are paper thin and wrinkle on sight.  Maybe even some heavier gauge sheet.

As I haven't got any really suitable thin board for the draw plate the plan now is to make a start on the wings and come back to the canopy when I have.

Pics.
Front, rear and side view of the test piece. You can see clearly that the rear step in the top line is more of a slope than a step.
Test piece very roughly cut down and perched on the fuselage to assess the "rightness" of it.


Title: Re: Junkers 87 B-2/R-2
Post by: Andy Blackburn on November 23, 2019, 02:38:19 PM
Dunno what thickness acetate you used, I normally use 10 thou on a canopy that size. Also, I find I have to leave a decent-sized gap around the plug (maybe 1/8") with rounded edges on the plate in order to get a decent canopy. I usually get best results by just shoving the acetate with the base under the grill and then pushing it over the form when it's steaming and gone properly floppy - I've never been able to get a decent result with a hot-air paint stripper, I'm a bit too cack-handed with it so bits of the acetate tend to overheat and bubble.

Had you considered moulding the gun "bubble" separately and then attaching it afterwards with dope or similar?...


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on November 23, 2019, 03:23:54 PM
Quote from: abl
I usually get best results by just shoving the acetate with the base under the grill....
Mrs Gordon, the Staff Canteen Head Cook, is not kindly disposed to staff from other departments encroaching on her domain.   The last time canteen equipment was put to uses other than catering was when one of the junior members of the establishment tried to dry off a freshly cleaned bike chain in an oven. Reader may wish to note that the smell of paraffin is not regarded as particularly pleasant by cooks.   Odd people cooks, everyone knows that, after benzene, it's quite the nicest smell.

Quote from: abl
Had you considered moulding the gun "bubble" separately and then attaching it afterwards with dope or similar?...
I hadn't.  I rather think I'd make a complete pig's ear of it if I tried.


Title: Re: Junkers 87 B-2/R-2
Post by: Russ Lister on November 23, 2019, 07:01:54 PM
Benzene?! It was taken out of circulation at my old school over 40 years ago. Considered quite a carcinogen now I understand. (About the same time as the chemistry teacher stopped walking around the class with radioactive isotopes...)


Title: Re: Junkers 87 B-2/R-2
Post by: flydean1 on November 23, 2019, 08:57:40 PM
As I recall, nitro-benzene was a key ingredient of the old "This Is It" UC racing fuel.  Went to many a speed meet "way back when" and luxuriated in the fragrance of "shoe polish" fuel.


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on November 24, 2019, 04:21:32 AM
Quote from: FreeFlightModeller
Benzene?! It was taken out of circulation at my old school over 40 years ago.
That'd be about right.  We were still using it in undergrad. labs in the early/mid 80s but it was "fume cupboard only" use and very, very rarely used at that. IIRC* toluene was the preferred alternative for use as a solvent.

Quote from: FreeFlightModeller
Considered quite a carcinogen ...
No "considered" about it.


*I may not. It was a long time a go and I was spectacularly rubbish at chemistry. :)


Title: Re: Junkers 87 B-2/R-2
Post by: billdennis747 on November 24, 2019, 04:44:30 AM
(About the same time as the chemistry teacher stopped walking around the class with radioactive isotopes...)
I think ours did that too but we were more interested in playing marbles with pools of mercury.


Title: Re: Junkers 87 B-2/R-2
Post by: Russ Lister on November 24, 2019, 05:20:00 AM
Lurker,
Yes, toluene was the substitute.

Bill,
Eee ... you were lucky. We had to make doo wit' asbestos fibres pulled from mat and put in t'bunsen to make flame turn orange.

How are we all still alive?!


Title: Re: Junkers 87 B-2/R-2
Post by: Russ Lister on November 24, 2019, 05:29:18 AM
As I recall, nitro-benzene was a key ingredient of the old "This Is It" UC racing fuel.  Went to many a speed meet "way back when" and luxuriated in the fragrance of "shoe polish" fuel.

I'll have to look that one up .... in my youth there was not much finer than the whiff of rapidly burning Castrol R 2 stroke oil!


Title: Re: Junkers 87 B-2/R-2
Post by: Squirrelnet on November 24, 2019, 06:39:03 AM
I still use Castrol R in an old bike I have , as you say Russ the smell  ;D

 


Title: Re: Junkers 87 B-2/R-2
Post by: Russ Lister on November 24, 2019, 07:57:39 AM
I've always been the "smellee " rather than the "smeller" if that makes sense?! As much as I have always loved bikes, my glorious collection only runs to a Suzuki ts50er and an Aprilia 125 Futura! The latter was worthy of Castrol, but ran on fully synthetic.

Anyways ... back on thread .... what did a Stuka smell of!  ::)


Title: Re: Junkers 87 B-2/R-2
Post by: billdennis747 on November 24, 2019, 08:24:26 AM
Lurker,
Yes, toluene was the substitute.

Bill,
Eee ... you were lucky. We had to make doo wit' asbestos fibres pulled from mat and put in t'bunsen to make flame turn orange.

How are we all still alive?!
No idea. Another wheeze was dipping fingers in ether and lighting. Found out by practical means that acetone isn't the same as ether.


Title: Re: Junkers 87 B-2/R-2
Post by: Pete Fardell on November 24, 2019, 09:41:20 AM
Don’t forget turning on and lighting a gas tap (with no Bunsen attached) to make an instant flame thrower with a useful 6 ft range.
Our physics teacher used to carefully remove the radioactive substance from its lead-lined box with tongs. However, by the end of the lesson he’d misplaced the tongs so he’d  put it back in with his fingers (but very quickly, before any radioactivity could rub off!)


Title: Re: Junkers 87 B-2/R-2
Post by: billdennis747 on November 24, 2019, 10:46:19 AM
Don’t forget turning on and lighting a gas tap (with no Bunsen attached) to make an instant flame thrower with a useful 6 ft range.
Our physics teacher used to carefully remove the radioactive substance from its lead-lined box with tongs. However, by the end of the lesson he’d misplaced the tongs so he’d  put it back in with his fingers (but very quickly, before any radioactivity could rub off!)
Yes we all did it in unison as Mr Thrasher (oh yes) turned back to the blackboard. It looked like the opening credits to Dallas.


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on November 24, 2019, 01:13:04 PM
My, my.  What a bunch of ne'er-do-wells and tearaways you all were.  I'm not sure that my mummy will let me play with such bad boys any more.  :)

On gun "bubbles".

I wasn't happy with the rake of the rear canopy, not shallow enough, too near vertical.  So hacked off the existing bump and sanded in a more correct angle before attaching a new bump.  As the bump worked moderately well in the initial test piece I'm hoping that a less "vertical" presentation will give an acceptably good result.


Title: Re: Junkers 87 B-2/R-2
Post by: cvasecuk on November 24, 2019, 02:26:36 PM
Our favourite trick was to blow down the gas taps in the physics lab so that all the bunsen burners in the chemistry lab upstairs would go out!
Ron


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on November 28, 2019, 03:24:05 PM
Another little deviation to keep the judges busy.  A bomb aiming window.  Thought I'd have a go a fitting it whilst other bits are settling.

Construction is dead simple.  The difficult bit is the modified keel with a dent in it which requires a degree of forethought.  The "window" itself is three bits of 80gsm paper.  Sidewalls are black ink, the window is silver crayon and the hinged cover panel is light blue crayon which is a fairly good match for the selected tissue for the underside. All held in place with smears of glue stick.  The camera is pretty unforgiving, but it looks reasonably convincing to the my (middle-aged verging on old) naked eye.

And just for the hell of it the first completed wing section, starboard outer.


Title: Re: Junkers 87 B-2/R-2
Post by: Andy Blackburn on November 30, 2019, 04:06:46 AM
Sadly (for me, anyway), whilst that is self-evidently not a "significant" deviation (I mean, you can hardly see it and it's hidden from view most of the time - hardly more than enhanced decoration, really) most judges would whip out their green pens and assign some penalty points.  :(

(If there are any kit scale judges reading this, please feel free to chip in and contradict - I need all the help I can get here!)

...
And just for the hell of it the first completed wing section, starboard outer.

As previously noted, I think you've safely accrued more than enough static points to earn a Full Monte breakfast at the Super Sausage Cafe, but I'm not going down without a fight. May I say, then, that the half wing looks exactly the same as the Albert E Hatful's original; well done on sticking to to plan, for once...


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on November 30, 2019, 07:24:50 AM
Quote from: abl
Sadly (for me, anyway), whilst that is self-evidently not a "significant" ...
Indeed, hence my use of the adjective, "little".

Quote from: abl
May I say, then, that the half wing looks exactly the same as the Albert E Hatful's original; well done on sticking to to plan, for once...
While it is customary to denigrate some of Mr. Hatful's plans for lack of scale accuracy, quite unfairly and unjustifiably given the relative paucity of good reference documentation available when they were drawn up as well as the commercial constraints required to make Keil Kraft's kits profitable and still provide something that almost anyone could build, it would be deeply worrying if the wing section did not look much the same.  However as noted in Entry No. 77, Attachment No. 4 (https://www.hippocketaeronautics.com/hpa_forum/index.php?topic=24583.msg250144#msg250144) (above) the wings are not exactly the same.  It will be seen that there is a noticeable difference in the sweep-back of the L.E., the shape of wing tip and the size and shape of the flaps.

Quote from: abl
I think you've safely accrued more than enough static points
I've lost track of penalty points garnered so far and there has been a troubling lack of comment from His Honour Judge (Jury & Executioner) Jack Plane so I really couldn't say.  Anyway the real test will be does the blessed thing fly?


Title: Re: Junkers 87 B-2/R-2
Post by: DavidJP on November 30, 2019, 12:10:44 PM
Must confess that I find it slightly alarming that some of you later taught/teach and behaved in such an irresponsible way.  So is such behaviour permitted today? 

I applaud you Lurk on defending our Albert.


Title: Re: Junkers 87 B-2/R-2
Post by: Andy Blackburn on December 01, 2019, 06:28:38 AM
...
I applaud you Lurk on defending our Albert.

I hope that the jury will accept my sincere and heartfelt apologies for any perceived denigration of Mr Hatful's skill and judgement as a designer; it was not my intention to deprecate the reputation or skill of Mr Hatful.

...

It will be seen that there is a noticeable difference in the sweep-back of the L.E., the shape of wing tip and the size and shape of the flaps.
...

Oh, come now - they look pretty much identical to me. Granted, there are some minor changes but they are surely very minor and could scarecely be regarded by any reasonable person as <ahem> "significant". The change in sweepback might just attract the odd point or two if the judge is having a bad day, but seen in the round they look very similar. I'm sure that his honour The Judge will correctly consider that any minor changes to be just that, particularly if they are not visible under the covering when subjected to a casual glance?

(I'm on a loser here, aren't I?)



Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on December 01, 2019, 08:10:30 AM
Slightly OT and joking aside it does sadden me when people have a go at any kit designer for the compromises necessary in a commercial product.  Mr. Hatful's Ju87 is quite a good example of this.  If you compare the wing & wing tip construction in entry 77 you'll see that his design is recognisably a Ju87 wing, uses relatively few complicated components and is well within the talents of the average 11 or 12yo to build well. Whereas my modified wing and wing-tip has some stupidly small fiddly bits and would be a complete non-starter as a kit suitable plan, even with laser cut parts, which were not an option 60 years ago.

Back OT.  Both outer wing sections, sans flaps, done.  UC legs test fitted. They seem OK. Will need to do a tiny bit more fettling to the UC legs to ensure they don't splay come final assembly, but so far, so good.

At the moment hoping for a mid January finish, but mid Feb. isn't beyond the bounds of possibility.

Cheers,
Lurk.


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on December 08, 2019, 01:43:36 PM
Unless anyone is especially desperate to see it I won't re-post the "Deviation Summary" that was lost when Ratz rescued the forum from the horrors of a <DBDGD>*.  If anyone would like a reminder for her or his own reference then please send a large stamped, self addressed envelope togther with a postal order for 5/3d to the Public Relations Dept. at  The Lurker Industries Aviation Co. Ltd.

Yesterday and today spent sorting the nose block and spinner.  Bit of painting to do before it all goes together.

I did think about using my home-brewed thrustline adjuster, but in the end I've gone for a fixed 3D, 3R as even with the slightly larger nose plug it's a bit cramped for the brasswork. If shims are required then so be it.  The airscrew is VMC's finest 6" and the spinner is also courtesy of VMC.  It's the one that comes with Andrew D's Hurricane and is a pretty convincing** substitute for no additional effort on my part. It's certainly more convincing than the original.  Hmmm, I wonder; does this count as another deviation?

Pics.  Setting up the thrustline, ensuring spinner disc and shaft-line are square, test fit of the whole boiling and a snipping from the KK plan showing the original combined spinner & prop.

Lurk
*One for all the DSM-11 (MUMPS) programmers out there. Oh. Just me then? Oh well.


**It's a model, not a facsimile.  Not only that it's also kit scale so while I want to get the overall shape right or as near right as possible with balsa and tissue I am not going to count rivets. :)


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on December 09, 2019, 03:35:54 PM
Thought it was about time I did something about that awful cheese-eating grin of a radiator inlet so this evening was spent testing an idea.  I think it looks a lot better.

Pics.
Testing blank for size, opening the grille out, sorting the rad. mesh and check piece resting in place.



Title: Re: Junkers 87 B-2/R-2
Post by: Squirrelnet on December 09, 2019, 04:21:03 PM
Nice job Lurk . No cheese will be harmed after the making that grill.


Title: Re: Junkers 87 B-2/R-2
Post by: Andy Blackburn on December 09, 2019, 05:09:14 PM
That does look a lot better. Nicely done.


Title: Re: Junkers 87 B-2/R-2
Post by: Jack Plane on December 10, 2019, 03:01:35 AM
You're racking up points faster than one can say "Achtung Spitfire!"


Title: Re: Junkers 87 B-2/R-2
Post by: Andy Blackburn on December 10, 2019, 05:17:15 AM
To be honest, I had originally thought that Lurk might make a few changes and might scrape through with 16-20 penalty points but I had obviously failed to take into account the vast resources provided by Mr Barnes-Norway and his team; I suspect that we're going to end up with 60+ penalty points which is extremely impressive. And in spite of Lurk's protestations, I think that (provided that it's straight and balanced properly) the attainment of the qualifying flight time will be a foregone conclusion.

I am therefore throwing in the towel (for those of you who are late to the party, see post #1 (https://www.hippocketaeronautics.com/hpa_forum/index.php?topic=24583.msg247586#msg247586))... well done, Lurk!  :)


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on December 12, 2019, 12:34:15 PM
Now.  Where were we?

Ah.  Yes.  The MG-15.  How to do the magazines.  I've worked out a moderately good solution.  As usual the execution is not all I hoped it would be, but not so bad that I'm ashamed to show the result.


Title: Re: Junkers 87 B-2/R-2
Post by: flydean1 on December 12, 2019, 10:10:17 PM
No ring sight? ;D


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on December 13, 2019, 03:16:15 PM
Quote from: flydean1
No ring sight? ;D
Of course there's a ring sight.  It's just not fitted yet.  Would you expect anything less of Mr. Barnes-Norway and his staff? :)

This is far and away the easiest bit to make.  Fine wire wrapped twice around a pin to form the loop then twisted to form the mounting post.

I doubt whether I'll bother fitting this come final assembly as it won't survive the trimming flights never mind the rough and tumble of a flying session.

You'll probably need to hit the, "Make It Bigger" button in the attachment viewer to see it.


Title: Re: Junkers 87 B-2/R-2
Post by: Squirrelnet on December 13, 2019, 03:21:14 PM
That's pretty impressive   :D


Title: Re: Junkers 87 B-2/R-2
Post by: strat-o on December 13, 2019, 03:51:25 PM
Let's get a closer zoom so we can see the spider silk crosshairs.


Title: Re: Junkers 87 B-2/R-2
Post by: Crabby on December 13, 2019, 04:56:30 PM
Lurk next time you are near a hardware store get a look at the fluted dowels they make for furniture connections they come in 3 sizes, just right, too big and way too big. You might like to use them on your machine gun. You will see what I mean once you get a look! That limburger-eating grin is really diabolical. Goering is giggling hysterically like a bowl of greasy gristle somewhere!


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on December 16, 2019, 01:47:10 PM
Quote from: Crabby
Lurk next time you are near a hardware store get a look at the fluted dowels...
Idea stolen noted for future use.  Ta.

Things are marching tres lentement ici.  The Humbrol matt yellow enamel (No. 24 for aficianados) is taking 48 hours per "waffer thin" coat to dry on the noseblock and spinner and I'm not minded to do anything else until I've got the nose block and prop. assembly completed.  Unfortunately I haven't got that colour in an acrylic version.


Title: Re: Junkers 87 B-2/R-2
Post by: Andy Blackburn on December 17, 2019, 03:50:44 AM
> The Humbrol matt yellow enamel (No. 24 for aficianados) is taking 48 hours per "waffer thin" coat to dry

That's a bit odd because it's normally bone dry in a couple of hours; I've only ever had that when a member of staff hasn't stirred/shaken it properly, although I could see it happening if the tin of paint was from a bad batch (happens, sometimes, with Humbrol). Perhaps the purchasing dept could persuade your supplier to donate a repalcement tin?


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on December 17, 2019, 04:54:07 PM
Quote from: abl
> The Humbrol matt yellow enamel (No. 24 for aficianados) is taking 48 hours per "waffer thin" coat to dry
... I've only ever had that when a member of staff hasn't stirred/shaken it properly...
Thoroughly stirred to make sure the pigment is well dispersed, yellow being such a very good colour* for covering dark surfaces so will go with your alternative hypothesis of a dud batch.  Hoping to get to a shop sometime in the next few days to pick up some acrylic matt yellow as I generally find acrylic paint far easier to work with.

Nose block close to complete.  The epoxy fillets between the prop and spinner are now hardening off and then slap a bit of paint on to finish off.

Just for fun here's a very short film, courtesy of those awfully helpful fellows at Merton Park Studios, of the spinner alignment testing prior to final fixing.  Alignment Check (https://vimeo.com/380109761)


*May contain traces of irony or even outright lie.


Title: Re: Junkers 87 B-2/R-2
Post by: DavidJP on December 18, 2019, 08:45:16 AM
I have not used Humbrol for a very long time but I do recall intermittent occurrences of problems with drying which I had rather thought has been solved.  I think otherwise the general standard of craftsmanship (which expression is deemed to cover any sexual orientation or gender preference. ) shows continual improvement.  I think though Lurk the standard of your finishes is consistent with paint being  “applied” rather than “slapped on”.


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on December 20, 2019, 03:52:17 PM
A very stiff letter of complaint has been sent by Mr. Grantown, Foreman of the Paint Shop, on behalf of Lurker Industries with the wholehearted backing of The Board to The Humber Oil Co. regarding the quality of its paint and the very poor drying time thereof.

Or...
Dud batch.  Tried some off-white and it was touch dry within an hour or three and rock solid the next morning.  Unfortunately my nearest (only) bricks and mortar stocks only Revell (and they are very poor about restocking) so I've had to go with a less than ideal replacement which is a bit brighter than it should be, but it was that or wait months to get the noseblock finished.  The block & spinner look less garish in natural light.

Various bits and pieces in progress.  Part way through assembling what I hope will be a totally unnecessary jig for wing fitting and playing around with ways of making the main ordnance.  The bomb sort of works, but I'm not convinced it's good enough to fit

Pics. Noseblock and assembly steps for the bomb.  The fins are 100gsm card, the casing 80gsm paper and the nose a scrap of balsa.  You'll note that it took several attempts to make it work. :)


Title: Re: Junkers 87 B-2/R-2
Post by: flydean1 on December 20, 2019, 08:55:50 PM
Where are the nose and tail fuses and safety wires? ;D, and the attachment lugs for the "trapeze"?


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on December 21, 2019, 02:35:46 AM
Quote from: flydean1
Where are the nose and tail fuses and safety wires? ;D, and the attachment lugs for the "trapeze"?
You can't see the fuses and lugs? I am surprised, they're as plain as the nose on your face.  In the words of the advert., "Should have gone to Specsavers."*  :)

As for the trapeze; I'm still pondering the best way to represent that.  A wire representation is likely to need jewellery grade materials and a require a degree of wire bending skill I don't have and, as I said above, I'm not convinced the main ordnance is good enough to fit.  If I can work out a good way of making the trapeze it might fly unarmed.


*For non-UK readers.  A chain of high street opticians that broadcasts allegedly funny adverts.


Title: Re: Junkers 87 B-2/R-2
Post by: Andy Blackburn on December 21, 2019, 04:09:39 AM
> As for the trapeze; I'm still pondering the best way to represent that.

Maybe a bit of plastic rod, bent in a candle flame?...

> I'm not convinced the main ordnance is good enough to fit.

Oh, I'm sure it'll be fine - and in any case, it's usually only visible when the model is in flight.

Of course, if I hadn't already thrown in the towel (see earlier posts), then in my best Dick Dastardly manner I'd be suggesting that you fill the bomb casing with sand or similar to make it more "realistic"... But I have, so I won't.


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on December 21, 2019, 05:02:30 AM
>> As for the trapeze; I'm still pondering the best way to represent that.
abl> Maybe a bit of plastic rod, bent in a candle flame?...
What a very good idea.  See below.

abl>Of course, if I hadn't already thrown in the towel (see earlier posts), then in my best Dick Dastardly manner...
Not only that, but suggesting solutions that may improve the verisimiltude of the model.  Are you quite well old fellow?

abl>  ...suggesting that you fill the bomb casing with sand ...
Well that is one way of limiting the model's endurance.  :)

Thanks to abl's suggestion above I now have four possible solutions.

In order of,  "from least to most likely to look like the prototype" they are,

- Thin card cut to pattern.
- Thin (5 thou) plastic card likewise cut to pattern.
- Slivers of bamboo cocktail stick. The cocking arm on the MG-15 suggests this might be possible.
- Heat stretched sprue. Luckily* I have a reserve kept for this sort thing.

For preference I'd like to make either the thin card solution or the bamboo slivers work as the other materials aren't the sort of things anyone but a dedicated modeller is likely to have to hand.

Lurk.

*MrsLurker's views on my hoard of bits kept because, "it'll come in useful one day" and mine are not entirely congruent.


Title: Re: Junkers 87 B-2/R-2
Post by: Crabby on December 21, 2019, 10:35:45 AM
Empty 500 mg vitamin capsules might make good bombs.


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on December 21, 2019, 03:44:07 PM
Quote from: Crabby
Empty 500 mg vitamin capsules might make good bombs.
They'd certainly make good casings for wing mounted bombs and that's another excellent idea I'm going to nab, but not for this build as the intended scheme for this build is an R2 which carried drop-tanks on the wings. I may duck the drop tanks as they've got compound curves which aren't amenable to the rolled paper tube approach used for the main ordnance.

Right. Who was complaining about the lack of trapeze and mounting lugs on the bomb casing?  Oh yes, I remember... :)

Here we go.  One trapeze, bomb fitted with, untrimmed, mounting spigots and all resting in position.

Split bamboo cocktail sticks work.  I don't think you'd get away with pine/softwood cocktail sticks because of the variable grain.

Take a couple of cocktail sticks, split and take the thicker "half" from each.  Bit of sanding to ensure the flat faces are flat.  Pin to plan* and then cut and fit cross-member and braces.  Use a full diameter cocktail stick for the cross-member.

For the casing mounting points a sliver of bamboo, shaved down to pin diameter.  Poke hole in casing with pin and put the bamboo sliver in place.  

Pics.  Trapeze in place and a pic from the Airfix 1/24th B2 kit - kindly lent to me by a work colleague - showing trapeze mounting detail for comparison.  Come final assembly poke a couple of holes in the tissue and glue the trapeze position.

*Mr. Barnes-Norway insists on drawings and plans for all sub-assemblies.  Quite strict that way our Mr. B-N. :)


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on December 22, 2019, 04:13:37 PM
The drop tanks are definitely going to be, ha  haa, dropped.

I think I can make them light enough.  Cut and shape in two halves out of soft balsa block then hollow out the centre of each half as per the test piece shown and then glue together.  However they look like they'll be horribly draggy.  They are big.  Very roughly 23/4" x 1/2".  The attachment shows the proportions against a wing outer section.  If this were a CO2 or electric build then it'd be worth pursuing, but not, I think, for a rubber powered model when there already some very draggy UC legs hanging down as well.


Title: Re: Junkers 87 B-2/R-2
Post by: flydean1 on December 22, 2019, 10:00:44 PM
Not to mention the need to install sway braces, latches, fuel feed plumbing and get the German stenciling correct. ;D


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on December 23, 2019, 02:49:13 AM
Quote from: flydean1
Not to mention the need to install sway braces, latches, fuel feed plumbing and get the German stenciling correct. ;D
Details, mere details old boy. Hmmm... the latches might be slightly awkward, but the fuel lines wouldn't be a problem as they were all plumbed internally so wouldn't be obvious once the tanks were in position and as this is a Picchiatello* I rather think the various instruction and information legends would have been overpainted in Italian.   :)


*An interesting re-naming.  Picchiatello carries connotations of battery (as in assault &), but also eccentricity or craziness and one wonders which aspect of the Ju87 was uppermost in peoples' thoughts when the name was assigned.  The quite frankly bats appearance of the thing or its capacity for inflicting damage?  It argues a, dark, sense of humour usually absent in the naming of these things.

ETA.  I'd be interested to hear what any Italian members of the parish have to say.


Title: Re: Junkers 87 B-2/R-2
Post by: Andy Blackburn on December 23, 2019, 03:38:53 AM
I wish I was still allowed to indulge in Dick-Dastardly-esque behaviour but that avenue of pleasure has been closed to me [misquoted from "Fawlty Towers", 1979]. :)

I think leaving off the drop tanks is wise. And I admire your courage adding all the weight associated with a 250 kg bomb and trapeze - I mean, it still has to achieve a minimal 12 second flight in order to avoid any unpleasantness with Avocado. How much does it all weigh at the moment?...


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on December 23, 2019, 05:01:20 AM
Quote from: abl
How much does it all weigh at the moment?...

No idea.  I'm expecting it to be a bit of a porker.  The plan is to get all the bits together see how heavy it is and if necessary discard non-essentials like the trapeze, bomb and even the MG-15.   I know that my Camel will fly at well north of 40g and K5083's weight in ballast, prior to trimming, was a fraction under 32g, but both of those have more generous wing area to play with than this one. 

Given the uncertainty over weight and flight capability your seconds are cordially invited to retrieve the towel from the ring where it was dropped quite by accident. :)


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on December 24, 2019, 11:58:32 AM
Last major structural item, the canopy, finally dealt with.  It's a long, long way from perfect, but after five (5) goes at it I'll settle for what I've got otherwise this will never get finished.  FWIW a hot air paint stripper is just about good enough as a heat source, but only if you have no better alternative.  Mid / late January is now looking like a realistic possibility for build complete.

I shall, of course, be using the seminal work on canopy framing (http://www.hippocketaeronautics.com/hpa_plans/details.php?image_id=10475) to complete it.

Pics.  Various views of the canopy in place.


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on January 03, 2020, 01:37:16 PM
"All right, Mr. DeMille, I'm ready for my close-up."  Ladies, Gentlemen, Girls and Boys the Publicity Dept. of the Lurker Industries Aviation Co. Ltd. presents.... the obligatory bones shots.

It is a porker.  Listen to it grunt.  :)  As pictured, sans flaps, main ordnance, trapeze, tailwheel and rad. gills, it registers 25g on the kitchen scales.  Some small consolation (barely a scruple's worth) is that weight (about 32 and half scruples as it happens) is with all the heavy-weight bits esp. the noseblock and main UC in place.  However I think I'm going to have to find my lightest balsa for the flaps.

Disappointed to find that I will need a jig for fitting the wings.  The port side is fine, but there's a bit of play in the slots for the wing tongue in the stbd wing which means it will need something to keep it aligned whilst the glue sets.  Sloppy building that man.


Title: Re: Junkers 87 B-2/R-2
Post by: OZPAF on January 03, 2020, 05:25:35 PM
Not bad - not to bad at all - for the first preproduction prototype! :) Now for the production version :D It looks good Lurk - give the workers a day off!.

John


Title: Re: Junkers 87 B-2/R-2
Post by: Marco on January 04, 2020, 02:13:13 PM
Quote from: flydean1
Not to mention the need to install sway braces, latches, fuel feed plumbing and get the German stenciling correct. ;D
Details, mere details old boy. Hmmm... the latches might be slightly awkward, but the fuel lines wouldn't be a problem as they were all plumbed internally so wouldn't be obvious once the tanks were in position and as this is a Picchiatello* I rather think the various instruction and information legends would have been overpainted in Italian.   :)


*An interesting re-naming.  Picchiatello carries connotations of battery (as in assault &), but also eccentricity or craziness and one wonders which aspect of the Ju87 was uppermost in peoples' thoughts when the name was assigned.  The quite frankly bats appearance of the thing or its capacity for inflicting damage?  It argues a, dark, sense of humour usually absent in the naming of these things.

ETA.  I'd be interested to hear what any Italian members of the parish have to say.
Hi all and happy new year !
My little contribution, to explain the joke behind the name 'Picchiatello' - 'Picchiatello' is said of someone who is happily crazy and nice; to give you an example, Jerry Lewis was called in this way in the italian version of some of his movies. On the other hand, 'dive', in italian,  is translated with 'picchiata'. No relation between the two words, but similar sound - so, in case of the Ju 87, 'Picchiatello' could be used as a funny nickname linked also to the mission of the plane (dive bomber, i.e. 'bombardiere in picchiata').
There are several jokes in the insignia of the Italian Air Force, the three green mice, for instance, on the S79 squadron as well as the black cat that is catching the green mice (on a fighter squadron), or the nickname 'Mammaiuto' ('Help me, mum') for the SAR planes.
Nice diversion...

Marco


Title: Re: Junkers 87 B-2/R-2
Post by: Marco on January 04, 2020, 02:29:52 PM
Just to provide a bit of constructive contribution...if you are going to build a Picchiatello, hereunder you can find a couple of pictures. The most distinctive character of these planes, perhaps, is that they were build as german aircraft, with german markings. Although the markings were coarsely covered once the aircraft were in Italy, they were still visible through the camo...


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on January 04, 2020, 03:52:04 PM
Ahh. Thanks for the unravelling of the joke behind the name Marco,  it makes perfect sense now.   Likewise thanks for the additional pictures; however I don't think my finishing skills are up to doing anything that good. I wish they were.  If you trek back to page 1 or 2 you'll see the scheme I'm hoping to  render.  I was going to do it with the RAF roundels, but as the CD expressed a preference just before Christmas for the original Italian scheme and I'm feeling charitable he can have it that way as a late Xmas present.   


Title: Re: Junkers 87 B-2/R-2
Post by: DavidJP on January 05, 2020, 05:22:50 AM
Have not looked at this topic for a while and am singularly impressed by the “bones” pictures Lurky old fellow.  It certainly looks like an eighty seven.  And the canopy looks good too.  Thank you for the comments on the heat gun - have been wondering how effective they were for that kind of thing.  The last time I did any moulding I used the ring on the gas stove - which worked well.

Marco, thank you for that explanation.  Amusing indeed.  The best I can think of as a match was “Wimpy” as a nic - name for the Wellington because of its plump appearance - after a cartoon character who was addicted to hamburgers! 

There is perhaps something happily crazy about a Stuka - from what I have read and heard you needed to be a little crazy to fly in one particularly if you were in the rear seat but as an aircraft it’s gawky and slightly prehistoric image can touch ones sense of humour.  Thank again for that gem of information.


Title: Re: Junkers 87 B-2/R-2
Post by: Andy Blackburn on January 08, 2020, 07:33:33 AM
Not bad at all, Lurk; 25 grams might sound calamitous but that does include all the heavy parts and I imagine that the c.g is currently in a relatively favourable position. I remain optimistic.

A.


Title: Re: Junkers 87 B-2/R-2
Post by: Jack Plane on January 08, 2020, 02:35:52 PM
Porky is quite okay, dear Lurk, after all it is supposed to dive...


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on January 08, 2020, 03:29:40 PM
Quote from: abl
Not bad at all, Lurk; 25 grams might sound calamitous...
My fingers are well and truly crossed unfortunately this is making covering a bit difficult.

Quote from: Jack Plane
Porky is quite okay, dear Lurk, after all it is supposed to dive...
Umm. Yes.  I'm fully expecting the "glide" at motor run out to be very prototypical but I'd quite like it to not try and burrow into the ground. :)


Title: Re: Junkers 87 B-2/R-2
Post by: Andy Blackburn on January 08, 2020, 04:53:10 PM
May I just point out that it only has to fly for 12 seconds from a hand launch in order to avoid any unpleasantness with avocado? And in any case I'm expecting something over double that (assuming that you're not using the original Keil Kraft 5" propeller).


Title: Re: Junkers 87 B-2/R-2
Post by: OZPAF on January 08, 2020, 06:37:32 PM
Perhaps launch from a high balcony :) With a siren the dive could be more than 12secs and realistic :) Actually I doubt that you will have trouble making 12secs!
John


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on January 11, 2020, 04:40:28 PM
Quote from: OZPAF
Perhaps launch from a high balcony...
I wouldn't want the CD thinking I was trying to cheat.  It just happens to be nothing more than pure, utterly innocent, coincidence that the initial flight trials are planned to be from Sutton Bank*.   :)

Covering and related decorative work proceeds at a glacially slow pace.  The attached pictures represent all progress since the 3rd.  Quite a lot of time gone into drawing and cutting templates as well as the usual experiments to work out the best solution for odd steps.  On which today's top tip is;  when your beloved receives expensive** clothes wrapped in extremely flimsy tissue paper do not throw that tissue paper away.  It may be absolutely useless for covering model aeroplanes, but it's first rate for wrapping around complicated bits of fuselage or wing as the first stage in making a card template.

Pics.  Underside and stbd side covered, a couple of shots of the wings, the underwing fasces and one tailwheel. 

I think I may have to recut the template for the fasces as I'm not quite satisfied with the two currently earmarked.  I'll live with the tailwheel as it is.  It satisfies my interpretation of the 4' rule.

Lurk.


*For non-UK readers.  A popular haunt of the gliding community.  Everyone's favourite search engine will reveal why.
**All ladies' clothing is expensive.  I have no idea why.  It's probably quantum.


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on January 13, 2020, 04:06:21 PM
The Directors have expressed their joint and several concern at the expenditure of the paint shop in recent weeks.

Or...
Five quid for not quite three (3) teaspoons of Indian Ink!?  Messrs Windsor & Newton you really are having a laugh aren't you?  All the way to the bank I'll bet.

Win some, lose some.  Have a satisfactory solution for the yellow band on the nose;  45gsm layout paper with a single v. thin coat of the enamel used to paint the nose-block and spinner; cut to size and glued (thinned PVA) in place.  Colour match isn't perfect; different substrates so to be expected, but it's a much better match than any of the yellow tissue I have and the layout paper means that the base colour doesn't show so doesn't need several coats of paint.  Unfortunately my cunning plan for the underwing fasces; ink on shrunk and doped tissue which are then cut from the carrier and doped in position is a dead loss.  A quick test shows that the thinned dope washes away the ink.  I may try using thinned PVA to tack the fasces in place, it seems to have worked OK for the yellow fuselage banding so it's got to be worth a go.  If that fails I'll be drawing them on 45gsm and colouring in the background with my pale blue crayon.  :)

A chapter in which our Hero utters an Heresy!

I think I prefer EzeDope.  

Nurse!  The economy size bottle of smelling salts as quickly as you like please.  You'd better deal with Abl first he looks rather too peaky to me.

OK, I am seriously out of practice with the grown-up stuff, but I'm not at all pleased with the finish on the fuselage when I compare it with my VMC Camel covered in the same tissue.  It's supposed a bomber so I'd expect and want a matt/flat finish and the dope leaves it with considerably more "shine" than the EzeDope.

Pics.  The fish were biting today and some views of the nose showing the yellow band.


Title: Re: Junkers 87 B-2/R-2
Post by: Andy Blackburn on January 13, 2020, 04:35:39 PM
> I think I prefer EzeDope.

I feel faint. Nurse!??....

A.


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on January 19, 2020, 10:21:33 AM
Aren't scale(ish) models a fiddle to finish off?  :)

Replaced the test bomb-aiming window with the production part today and many of you will be gratified to hear that in keeping with Co. tradition this model also uses domestic Al. tissue albeit only a tiny fragment for the "glass" in the window.

It's too late for this airframe, but you'll see that the lower stringers and keel aren't level enough and the the forward part of the window which should be flush with the fuselage up to the "hinge" line slopes down. An annoyance, but never mind.

Work continues on covering wings and other decorative niff, naff and trivia.

Pics.  Couple of views of the "production" window.


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on January 25, 2020, 04:43:29 PM
Started on the splinter camouflage yesterday and as I feared I am making a bit of a bish of it, but no ticket monies will be refunded as I did state this to be the likely outcome way, way, waaayy back in September. :)

Fuselage done. Result is a bit, "meh".  Stbd wing in progress, still a couple of patches to do.  Had to do re-do the LE panels as separate panels, my, my what a fiddle, because no amount of vituperation or hacking with a scalpel would persuade them to lie any where near flat.   A close up view shows that they're still distressingly "bubbly".  Rather saddened by this as the base tissue covering was (by my standards) good.  Never mind; at squinting distance on a foggy day they'll pass.

On the upside the chosen tissues (VMC Olive, Racing Green & Easybuilt pale blue) are a pretty good match, for KS, to the prototype's scheme.

Pics.  Views of fuselage, the "bubbly" panels and the reasonably good base covering for comparison.


Title: Re: Junkers 87 B-2/R-2
Post by: Andy Blackburn on January 25, 2020, 05:09:14 PM
> ...A close up view shows that they're still distressingly "bubbly"...

Looks fine to me.

However, if you haven't doped the Dunkelgrun tissue yet, you should find that if you carefully slit the bubble(s) and then drop some water on each one from a soft brush, it'll shrink down nicely.


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on January 25, 2020, 05:16:21 PM
> ...A close up view shows that they're still distressingly "bubbly"...
Looks fine to me.
I think I shall reconsider your recommendation to invest in varifocals. :)

Quote
However, if you haven't doped the Dunkelgrun tissue yet...
Too late; already doped and the stores wallahs say they're completely out of shrinking dope and aren't likely to get any in the foreseeable.

ETA.
Hang on a mo.  Did you mean the Schwartzgrun?  Because that hasn't been doped "properly", just "thinners flooded" onto the doped Dunkelgrun base.


Title: Re: Junkers 87 B-2/R-2
Post by: RolandD6 on January 25, 2020, 08:25:20 PM
Is there anything in the kit scale rules that say you must use colour tissue for such things as splinter camouflage?

I have been experimenting with Faber-Castell Pitt pens and brushes. The inks are claimed to be water proof “India” ink and the pens come with brush tips, a medium sized fibre tip and a fine fibre tip. I have found it possible to paint a 1 mm line using the brush tip and a suitable guide held well off the paper. The tissue paper needs to be sealed with dope or ink to prevent wicking along the edges.

There are a lot of colours available as individual pens, at least there are at art shops near me.

For what it may be worth

Paul


Title: Re: Junkers 87 B-2/R-2
Post by: Andy Blackburn on January 26, 2020, 09:18:55 AM
> Hang on a mo.  Did you mean the Schwartzgrun?

Did I not say Schwartzgrun? Oh dear. I meant Schwartzgrun; sorry, should have been paying attention.

<ahem> if you haven't doped the Schwartzgrun tissue yet, you should find that if you carefully slit the bubble(s) and then drop some water on each one from a soft brush, it'll shrink down nicely.

<RolandD6>
> Is there anything in the kit scale rules that say you must use colour tissue for such things as splinter camouflage?

The 2020 rules don't seem to be out yet but the 2019 rules had this clause "It is expected that most models will have a coloured tissue finish with painted, printed, transfer  or  tissue  markings.    Fully painted  models  or  those  using  extensive  computer generated colour schemes will not be excluded but will have 5 marks deducted from their static score.".

So, if you've drawn it on the tissue yourself, I think you're OK. Unless they've changed that clause for 2020.



Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on January 26, 2020, 11:40:10 AM
> Oh dear. I meant Schwartzgrun; sorry, should have been paying attention.
Ah. That makes more sense.

Starboard wing bar flaps and some discreet water shrinking, see above, camouflage is complete, nothing new to see there.

UC test fitted and all levelled up so that, barring variations in wheel circularity*, it'll sit level.  One UC main leg covered and recognition number applied.  Covering went reasonably well, but there are bits that I can improve on for the stbd leg.  

Referring to the extract from rules above.  The recognition number digits are cut from pre-shrunk tissue with a coat of matt white acrylic (Revell if matters) and stuck on with thinned PVA.

If I were counting rivets the top third or so of the leg would be Dunkelgrun rather than Schwartzgrun ,see the Airfix scheme reference, but I'm not so yar boo sucks. :)



*Still sanding wheels to shape by hand.  Will sort out some sort of "lathe" at some point.  Eventually.  Maybe.


Title: Re: Junkers 87 B-2/R-2
Post by: Squirrelnet on January 26, 2020, 12:48:04 PM
That's looking very smart Lurk. The markings work very well.

 


Title: Re: Junkers 87 B-2/R-2
Post by: USch on January 26, 2020, 05:05:03 PM
…. Will sort out some sort of "lathe" at some point.  Eventually.  Maybe....

Lurker,
a few weeks ago we made a journey to Marocco and your remark brought back a "lathe" I had seen and photographed at the souk/market of Marrakech. Not to good a picture but the guy was so incredibly fast, the light was much less than ideal and me not prepared to see something similar.

Anyway, the lathe, made out of 3 wood blocks, was laying on the floor, had 2 center pins to hold the raw wood piece and the rev's where applied by hand with sort of a bow which you may just immagine in his right hand (red arrow). The cutting tool was held by hand at one end and pressure applied by the right foot. In less than a minute the guy turned out the pendant shown.

You see, with just a wee bit of imagination you can do a lot of things without spending a fortune  ::) ;)

Urs


Title: Re: Junkers 87 B-2/R-2
Post by: OZPAF on January 26, 2020, 05:13:27 PM
Very effective and neat covering effort Lurk.

John


Title: Re: Junkers 87 B-2/R-2
Post by: vintagemike on January 27, 2020, 05:52:46 AM
Its amazing what the Moroccan turners can turn out given their rudimentary equipment. Some stuff turners in this country wouldn't tackle even with the latest in variable speed lathes and the latest specialised tooling! Needs must I suppose, they are all trying to make a living. I will stick with my 35 year old Record lathe making my few bits and pieces to try and earn a crust!


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on January 27, 2020, 03:15:20 PM
Quote from: abl
...you should find that if you carefully slit the bubble(s) and then drop some water on each one from a soft brush, it'll shrink down nicely...
It does.  Thanks for that.

Quote from: USch
...a journey to Marocco and your remark brought back a "lathe" I had seen and photographed at the souk/market of Marrakech.
His wife is going to have a fit when she sees the state of her best carpet.  Thanks for that; all I've got to do now  is persuade MrsLurker to let me set up a bow or pole lathe in the dining room.  :)

Quote from: USch
...with just a wee bit of imagination you can do a lot of things without spending a fortune...
Oh I like not spending a fortune and I have a cunning plan involving what's left of my Meccano, but I've got to rescue it from the loft first.

In other news.  Stabiliser stripped this evening and being re-covered.  Had picked up a bit of a warp and steaming it to get rid of it made things worse.  Mildly annoying.


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on January 31, 2020, 03:47:08 PM
Canopy framing done, stab. re-covered and fin and rudder almost covered.  

Pics:  
Canopy in progress & finished.
Snippet from the Airfix 1/72nd kit scheme notes for comparison.  You'll see I've made some simplifications.
And a part covered fin & rudder.  Tissue is pre-shrunk.

You'll note that the framing around the gun bubble is more elliptical than circular, that's down to poor fabrication of the moulding plug.  I was following the curve of the bubble in the acetate, but it's good to know for future reference that circular canopy framing with tissue is not impossible given a good curve to follow.

Most of the bottom border of the canopy, barring about 1/16", will disappear into slots in the fuselage covering.

Tomorrow will dig out a 000 or 0000 brush and go over the canopy framing with thinned dope, bit too late today for any more "fine" work.


Title: Re: Junkers 87 B-2/R-2
Post by: Squirrelnet on January 31, 2020, 04:03:10 PM
The canopy lining has worked brilliantly Lurk.

 I will be stealing this method  ;D. I have a stalled Guillows Ju 87 project and one of my stalling points was the canopy and finishing it... along with plastic nose which you have also shown me an alternative way of doing it with your KK version

Yours looks light and delicate... mine looks like an exercise in basket weaving  ??? I think I need to reach for the sand paper...

Inspiring stuff  (Please don't laugh too much at the picture)



Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on January 31, 2020, 04:27:09 PM
Squirrelnet>The canopy lining ... I will be stealing this method
Well that is flattering.  :)  It's not difficult, but it is time consuming.  It took about 5+ hours, a good deal of which was "walk away" time to let the glue (50:50 pva) go off between sections of framing.

> Yours looks light and delicate... mine looks like an exercise in basket weaving  ??? I think I need to reach for the sand paper...
> Please don't laugh too much at the picture
It looks like a straight and clean build to me, nothing to be embarrassed about there and thanks for the pic. 'cos the more contributions to the thread the merrier and the more instructive and entertaining it becomes.

Guillows do seem to make their kits on the robust side.  I assume that's because they have sell to a very wide range of builders from glue-happy 10 year olds to those of a more *ahem* mature disposition to stand any chance of making a profit and a robust kit is more likely to get from board to airborne than something more delicate so boosting the chance of repeat business. 


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on February 01, 2020, 05:02:17 PM
Plugged together what I've got so far to see how close it's going to be to what I was trying for.   Ahh, the moment when cold hard reality collides with the dream.  :)

Still quite a few days effort to go before build complete.  Oddly enough the things that're causing me the most grief are the exhaust stacks.  I had them pegged as any "easy" task.  Hmmph!

Obvious things wrong
1) Canopy needs* remedial work to line of tissue on stbd side.
2) The canopy doesn't sit as well as I thought it would.  So much for that bright idea.
3) Stbd UC leg. I could have sworn I'd smoothed the curves on that better than that.

Pics.  Plugged together waiting quite a fews bits & bobs.

*Needed.  Done, but need to wait to see if "fix" has worked.
 


Title: Re: Junkers 87 B-2/R-2
Post by: OZPAF on February 01, 2020, 06:34:03 PM
Not bad Lurk. Very Stukerish actually :)

John


Title: Re: Junkers 87 B-2/R-2
Post by: Pete Fardell on February 01, 2020, 07:39:34 PM
Looking good! I really like the tissue camo/yellow nose contrast. The cheeky grin effect in the front view shot is most endearing (although if a real one was homing in on me with its siren screaming perhsps it wouldn't seem quite so cute).
Amyway, nice work and an interesting and entertaining build as usual.


Title: Re: Junkers 87 B-2/R-2
Post by: Andy Blackburn on February 02, 2020, 04:16:41 AM
Looks excellent, Lurk. I think you've successfully captured the essence of Stuka. I do like how it looks, even before the markings are applied.

We shall see what his honour The Judge thinks (if we can persuade him to stop being Nautical for an hour or so) but by my reckoning you're on somewhere between 50 and 75 penalty points, which is an excellent achievement of which you must be very proud. If you can persuade it to remain airborne for at least 12 seconds (which, if its sufficiently straight, will not be a problem) then the top prize of a "fry-up at either the establishment of the contestant's choice, or the Super Sausage cafe, Towcester" is yours. Well done.


Title: Re: Junkers 87 B-2/R-2
Post by: OZPAF on February 02, 2020, 04:22:44 AM
"Super Sausage Café" ?? The horrors oa 12 sec flight must be worth it for that! :D

John


Title: Re: Junkers 87 B-2/R-2
Post by: SP250 on February 02, 2020, 04:35:14 AM
You sure you want to go to the Super Sausage Cafe at Towcester for the prize fry up?
Lots of those ruff tough bikers go there - might be a bit intimidating for you arty / intellectual aeromodeller types!

John M


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on February 02, 2020, 02:40:47 PM
Quote from: OZPAF
Not bad Lurk. Very Stukerish actually :)
Aye, "ish" but it is kit scale not open so I'll take "ish" and gladly at that.

Quote from: Pete Fardell
The cheeky grin effect...
Oh dear, and there was me hoping to achieve, "menacing".

Quote from: Pete Fardell
... entertaining build as usual.
Why thank you folks. I'm here all week and don't forget to tip the waitress.  Just as well these builds are entertaining, one hopes they are, it's large part of the fun for me, cos they don't have much else to recommend them.

Quote from: SP250
Lots of those ruff tough bikers go there - might be a bit intimidating for you arty / intellectual aeromodeller types!
I'm sure that they are all nice boys and kind to their mothers and small animals.  Anyway I'm not afraid cos, as any fule kno, Abl is a big ruff tuogh biker type and will uterly tuogh any oiks up if they lack manners.  Hello birds, hello sky.

Now, why did I come here?  I'd better go back downstairs and see what I've forgotten ...
Grams: Footsteps down in to cellar & back up.

Oh yes, now I remember.
Tidying up the unsatisfactory canopy and ....

Quote from: abl
... like how it looks, even before the markings are applied.
... but by my reckoning you're on somewhere between 50 and 75 penalty points

... applying Squadron codes and the stbd wing fasces as well as adding another tiny detail, stbd air inlet, missing from the KK kit in a desperate attempt to squeeze even more penalty points out of it.

For those interested.  The squadron codes are as the aircraft recognition number on the UC legs, details above, and the fasces are Indian ink on pre-doped tissue with a spritz of aerosol satin varnish for water resistance. Indian Ink doesn't seem to "take" especially well to doped tissue as I discovered while applying the first upper wing fasces, bad words may have been said, hence the varnish. They're held on with 50:50 by vol PVA, water.

As for the canopy; the Schwartzgrun should extend to some of the framing, but there's attention to detail and there's masochism so I'm content to run it into the lower frame and come final assembly run fillets of the appropriately coloured tissue in to hold it in place.  If I don't stuff it up I think the result will be OK.


Title: Re: Junkers 87 B-2/R-2
Post by: Rhys on February 03, 2020, 10:09:42 PM
So sorry I'm just now replying to you fabulous built, TL !  Your execution of the build is really inspiring. Reminds me of a  plastic 1/24 scale Airfix kit I assembled for an IPMS meet in the latter 1970s. The splinter camp is ideal. What was your incentive to use the Regia Aeronautica rather than the Balkankreuz? I like your choice.
Again, really nice craftsmanship  ;D

Rhys


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on February 04, 2020, 11:41:15 AM
Quote from: Rhys
Reminds me of a plastic 1/24 scale Airfix kit....
Funny you should say that, a work colleague lent me his as yet unbuilt 1/24th kit over Xmas.  Was v. useful for a number of details esp. the trapeze. Interestingly they're still using the 1970s moulds for the 1/24th and they're still regarded as v. good as far as scale details go.

Quote from: Rhys
What was your incentive to use the Regia Aeronautica rather than...
Reasons of conscience.  See your personal messages.

Quote from: Rhys
Again, really nice craftsmanship  ;D
Careful now, the rest of the staff at Lurker Industries are already making pointed remarks about needing wider doors to the boardroom and it's yet to fly soo.... :)  But thanks for the kind words.


Speaking of plastic kits.  Any member of the parish interested in the 1/72nd kit?  I bought it as a reference for this build and as I have about 8 (yes 8 or is it 9?) 1/72nd Hurri kits ahead of it in the queue it's never going to be built up by me.  


Title: Re: Junkers 87 B-2/R-2
Post by: Jack Plane on February 04, 2020, 03:38:46 PM

We shall see what his honour The Judge thinks (if we can persuade him to stop being Nautical for an hour or so)...


His Honour is keeping right out of it... until the endeavour is complete and ready to be assessed.

 ;D


Title: Re: Junkers 87 B-2/R-2
Post by: Andy Blackburn on February 04, 2020, 05:52:37 PM
Apropos nothing, I happen to have a bottle of Navy Rum sitting on the sideboard. I don't drink it but I'm sure it would make Admiral Baron Von Markovitz' onerous judging task pass so much quicker...


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on February 05, 2020, 03:00:14 AM
Oh I say! That's really not on.  A blatant attempt by those bounders at TTOR to influence his Honour the Judge.  Not only bribery and corruption but offering inducements of a sort likely to affect his hard earnt and well deserved reputation for clear thinking and reasoning by intoxicating him.  I really must protest.  I shall be taking this up with the STC of the BMFA and failing that I shall be resorting to The Hague.  Harrumph!


Title: Re: Junkers 87 B-2/R-2
Post by: Andy Blackburn on February 05, 2020, 03:46:47 AM

...A blatant attempt by those bounders at TTOR...


I have been authorised by The Board to convey their thanks for this belated recognition of their talents, albeit a little late in the day. It was worth a try, since nothing else has worked...  :)


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on February 05, 2020, 03:49:06 PM
And today's lesson O Best Beloved is, "How the Ju87 got his Exhaust Stacks and Why It Should Not Have Taken Half so Flaming Long as it Did."

Pics.  Some exhaust stacks of very indifferent quality and a reworked bomb cos I wasn't happy with the earlier attempt; which is also shown for comparison.

Why the pics of such unremarkable bits?  Well, you see the bits - I'm sure there's a German compound word running to 10 syllables for the part, but we'll stick with "bits" - that curve around the nose block?  Yes those bits.  It took between 6 & 7 hours all told  with various starts, abandonings and restarts to get the inner curves on those to sit nicely against the nose-block.  Now this is foolish.  If I had been thinking about it with even half one quarter of my brain cells I would have cut slots in the nose-block with nice,  easy to cut straight edges and slid the curved bits into them.  It would have taken and hour, tops, and the join would have been near invisible.  There are times - oh so many times - when my stupidity astounds me.


Title: Re: Junkers 87 B-2/R-2
Post by: ffadict on February 05, 2020, 09:57:50 PM
Following along with great interest here. I think the prospects of avoiding the dreaded green hash toast are looking very good  :). 

There are times - oh so many times - when my stupidity astounds me.

When I am beset by the same problem (with great frequency I may add) I find that the best solution is to get out my unicycle and see how fast I can go. This ritual is usually followed up by a sound of scraping along asphalt as I discover that my top speed (18 mph) the hard way  ;D

But more to the point, any way you look at it your work is beautiful. My unfinished models are looking at me with accusing expressions, asking why they aren't progressing so well. Happy building!

Paul


Title: Re: Junkers 87 B-2/R-2
Post by: OZPAF on February 05, 2020, 10:02:37 PM
Perhaps you could have moulded a wet noodle around the cowl for your exhaust pipes Lurk.  :) They look ok to me.

John


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on February 08, 2020, 02:06:03 AM
Quote from: OZPAF
Perhaps you could have moulded a wet noodle around the cowl...
I shall try that next time I want to do something like this.  Seriously.

It occurred to me last night that we (as a group) generally only post when we're happy content with the results so for a change I thought a pic of stuff that needed more than a few goes to get right would be in order.  I wish I'd thought to do this earlier in the build.

Pic.  Attempts to get the fasces sorted.  This is the second set of attempts with a second stencil.  I binned the first set weeks ago.

I think for any future build thread I shall make a point of photographing and sharing the blunders as well as any successes.  I wonder if there enough electrons to spare? :)


Title: Re: Junkers 87 B-2/R-2
Post by: OZPAF on February 08, 2020, 05:44:16 AM
Ah takes me back to my manual draughting days. A 0.8 pen and possibly 0.35 for the lighter lines with a 0.25 or 0.18 circle.
You didn't do that all freehand Lurk did you?

John


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on February 08, 2020, 04:24:26 PM
Quote from: OZPAF
Ah takes me back to my manual draughting days....
You didn't do that all freehand Lurk did you?
Aye, right. A right wee Leonardo da Vinci I am.  Nooo.  Stencils* and my ancient drawing kit from when I when did O grade Tech. & Geom. Drawing.  I was just going to use felt pens, but I didn't have one that gave a bounding circle with a card stencil that looked the right thickness so that was done using springbow pen compass and Indian ink.  A picture for (the other) wrinklies of the parish who remember a time before CAD.

In other news; final assembly has started.  Had hoped to have it done today, but I'm pausing before I do something careless.  Really hoping to have it all done and dusted as far as construction is concerned by this time tomorrow.

Lurk.

*Reminds me, must get my hands on some No. 13 (parrot beak) blades.  The 15s are not sufficiently fine to give a good narrow curve.  If you look at the bottom of the fasces you'll see that the rounded ends are a bit ummm, variable.


Title: Re: Junkers 87 B-2/R-2
Post by: flydean1 on February 08, 2020, 10:21:07 PM
Lurk,

That shot of your drawing instruments awakened old memories of my Engineering Drawing class in High School.  That's about 57 years ago.  I still have it.  Almost identical to yours.  Mine was a Dietzgen, I think.  Probably speled rong.


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on February 09, 2020, 10:05:02 AM
Quote from: Messrs. Grabbit, Scuttell & Dashe
Dear Sirs,

My client has directed that a protest be submitted as he feels that the board of Lurker Industries has identified a (regrettable) gap in the rules; my client informs me that the member of staff responsible for drafting the rules will of course be subject to the usual sanction.

As you will no doubt be aware, the Ailerons and flaps of the Ju 87 sit below the wing trailing edge and the standard Keil Kraft plan mirrors this arrangement by using small pieces of 1/16" square to fit the flaps to the wings, as shown in the bottom right-hand corner of the plan.

However, the most recent picture of Lurker Industries' Ju-87 build appears to show the ailerons and flaps attached directly to the trailing edge of the wing.

Now, obviously, this departure from the plan should be covered by rule #4 ("If the judge considers that a particular change is detrimental to the overall character of the model, no points will be awarded for that change.") because it clearly changes the overall look and character of the model, but my client considers that this sanction is not sufficient.

The reason for this unusual and forthright view is that my client has submitted the pictures to a number of independant aerodynamic analysts, the unanimous opinion of whom is that moving the ailerons and flaps up to the trailing edge will confer a significant aerodynamic advantage by reducing the drag associated with the original 1/16" wide slot, thus making the achievement of a minimum 12 second flight even more likely than it already is.

My client considers that a fair and reasonable penalty for such a gratuitous change would be:
For each surface that has been moved (6 in all), remove 10 points from the total of penalty points that have already been awarded, and
For each surface that has been moved (6 in all), add 2 seconds to the minimal duration requirement.

I await the judgement of the court with some degree of interest.

sincerely

J Grabbit (acting for the board of Testwood Towers Operational Research)

Mr Barnes-Norway, after much careful and considered thought had the following to say, "Awa bile yer heid..."  and he, most unusually for a Sunday afternoon, not having yet had his accustomed sherry.

After a little further thought (and a fortifying glass or two of sherry) he went on to say, "If there is a gap in the rules then no rule can have been infringed so no sanction is applicable. " he also went on to point out that the flaps are attached in a similar manner to that indicated in Mr. Hatfull's plan; split cocktail stick replacing 1/16" balsa strip and that TTOR's ambulance chasing shysters should be,  to use a delightful American phrase, "Run out of town on a rail."  Nor does this trivial difference represent a change to the overall look or character of the model.  The enclosed photographic reproduction is presented as evidence of adherence to the spirit as well as to the letter of the rules as originally drafted.




Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on February 09, 2020, 10:54:14 AM
The Lurker Industries Aviation Co. Ltd. is pleased to announce the roll-out of its latest machine, a licence built Junkers R2.  The Board of Directors has expressed every confidence that this will be a market-leading addition to the already highly regarded range of aeroplanes constructed and sold by Lurker Industries Aviation and many export as well as domestic orders are expected to be placed desite some doubts expressed by other, less well regarded, aeronautical concerns.

Or...
Ladies, Gentlemen, Girls & Boys, Tobitd has been reached.  Despite Abl's late protest I'm calling construction done, barring the shouting. I've still got to fit the stabilizer braces and elevator mass balances but I need to do that slowly and carefully so am downing tools for the day to rest my patience and powers of concentration.

That was the good news.  Now the less good.

Unballasted (with a few cocktails sticks thrown is as make-weights for the stab braces) it tips the scales at 33g cf 30g for K5083.  More worryingly it's balancing between the LE & main spar and given that wing plan I'd expect it to further back than that so tail weight (*shudders*) may be required on an already weighty machine.  I am now cursing my attempt at the open rad inlet which has left some 1/32" ply reinforcing up front.  Am also seriously considering drilling holes in the back of the nose-block to ease the nose-heaviness a little.  I had harboured the, wildly optimistic, hope that it might be light enough to fly indoors, but I'm not that surprised that it's not.

ETA - That 12s qualifying flight time is looking pretty ambitious now.

Pics. Various views of the beastie as it is now.  Heir to the usual Lurker tissue wrinkles and build asymmetries* but it looks not unlike a Ju87.  

I'll post a bit more when I've had a natter with the CD who is, despite the weather, out gallivanting somewhere at the moment and not answering his telephone.

*A polite way of saying, "cock-ups".  :)




Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on February 09, 2020, 01:11:12 PM
Quote from: flydean1
...Engineering Drawing class in High School.  That's about 57 years ago.  I still have it.  Almost identical to yours.  Mine was a Dietzgen, I think.  Probably speled rong.
You have the advantage of age experience over me. :) 
My drawing kit, Berrick, is slightly younger than yours; it only dates from 1977.


Title: Re: Junkers 87 B-2/R-2
Post by: Squirrelnet on February 09, 2020, 01:19:37 PM
My congratulations to Lurker Industries for a very good looking Ju87 a credit to all the team involved.

Personally I think the threat of avocado toast has passed, if it looks that good it can't fail to fly


Title: Re: Junkers 87 B-2/R-2
Post by: Pete Fardell on February 09, 2020, 01:30:15 PM
That's one really good looking Stuka, Lurks. I'm sure it'll fly, indoors as well as out.
(And it is a dive bomber after all, so you'll only need tail weight if you want to replicate the pull-out section of the flight as well as the screaming-swoop-of-doom part.)


Title: Re: Junkers 87 B-2/R-2
Post by: Russ Lister on February 09, 2020, 01:52:01 PM
Very nice Lurker .... it has to fly  :)


Title: Re: Junkers 87 B-2/R-2
Post by: USch on February 09, 2020, 02:02:05 PM
Compliments to the Lurker Industries Aviation staff, great bunch of technician's. Couldn't have be done by a single worker  ;)

One thing though, does Lurker Ind. have a specialist for acoustic matters? The Stuka did indeed have a alarm siren to scare the population during the attacks.

Urs


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on February 09, 2020, 02:06:00 PM
Thanks Gents; the kind words are appreciated, but if TTOR's last challenge carries any weight with His Honour I'm doomed, doomed I tell ye.

Sirens?  Blast! I knew there was something I'd forgotten!

To business.  

Earlier I said I'd post more if the CD telephoned. He has.  I am now honour bound to tell you that what you see is not the Keil Kraft Ju87, but I think most of you had already worked that out.  It started out as the KK kit, but the points of similarity between the original* plan and a B2/R2 were few and far between so we have ended up with a brand new plan.  In my defence I will say that the LE of the fin/rudder and the KK kit are the same and in keeping with Keil Kraft's idiosynchratic wood selection policies I made no attempt to select especially** light wood from my stock so that (in spirit at least) it is a Keil Kraft production.

Pleasingly (well, sort of, in a "oh you juggins" sort of a way) I managed to get one thing notably wrong and that is the cross-section of the fuselage near the tail;  it should be more oval than rectangular so Albert gets his revenge for my presumption.  I didn't pick up on this until I had the built fuselage in my hands, seems there's something to be said for modern 3-D tools after all eh? Unfortunately my build schedule didn't have enough slack in it for a brand new fuselage to be built.  It isn't an irretrievable foul-up though as it only requires a change to one frame and a slight rejigging of stringer alignment to correct.

It only remains to say that if it flies (and you can see now why I'm a mite worried it might not) the, corrected, plan will be published somewhere. Although it might involve signs saying, "Beware of the leopard."

Lurk.

*The more I look at the KK plan, the more I think it's meant to represent a Dora rather than a Berthe.
**Given the weight I now wish I had.  Hey ho. :)


Title: Re: Junkers 87 B-2/R-2
Post by: Andy Blackburn on February 09, 2020, 02:24:53 PM
I have to say Lurk that notwithstanding the outstanding protest, it looks quite Ju87-ish. Very nice indeed. It's not until you look at the top view that the length of the nose becomes apparant. If it's still a problem after the rubber is installed, then maybe you could move the rear peg back one bay? It's not a big job because there's no paint to touch-up.

> ... but if TTOR's last challenge carries any weight with His Honour I'm doomed, doomed I tell ye.

Nonsense, my good man. Pull yourself together - you don't find me complaining, do you? Well, then...  :)

I am very confident that your Ju-87 will attain the minimal duration expected of aeroplanes produced/designed by TTOR*

A.

* 25 seconds.



Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on February 09, 2020, 02:32:46 PM
Quote from: abl
...maybe you could move the rear peg back one bay? It's not a big job because there's no paint to touch-up.
It's certainly worth considering.  It would mean re-numbering and re-applying the tail band, but that's all tissue work so it wouldn't mess up the appearance too much.  See how it goes with flight trials.  If it flies acceptably as is I'll leave this particular airframe well alone and mark up the plan with the alternative peg location.   

Five and twenty seconds!?  Oh dear, please excuse this fit if hysterical laughter I thought you said 25 seconds.... oh, wait, you did.  Tell me, is there a remedy for incurable optimism?

Quote from: abl
> ... but if TTOR's last challenge carries any weight with His Honour I'm doomed, doomed I tell ye.
Nonsense, my good man. Pull yourself together - you don't find me complaining, do you? Well, then...  :)
Aye, but you like avocado.  :)



Title: Re: Junkers 87 B-2/R-2
Post by: Andy Blackburn on February 09, 2020, 04:22:17 PM
But I'm going to have to fork out the brass to pay for your 300 tons of black pudding...


Title: Re: Junkers 87 B-2/R-2
Post by: OZPAF on February 09, 2020, 07:57:36 PM
Black pudding? The staff of Lurker Industries deserve a reward surely. :)

I think Lurker Industries could be trusted with an order for more licence built Stuka's after this fine effort. Pat the man on the back but don't give him black pudding.

That's a fine drawing instruments set Lurk - I was a manual draughtsman from around 1970 to 93 and my set is nowhere near as good!

John


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on February 10, 2020, 01:22:01 AM
Quote from: abl
But I'm going to have to fork out the brass to pay for your 300 tons of black pudding...
It'll still be cheaper than 3oz of Hand Picked Sun Ripened Avocado mashed with a Blackthorn Shillelagh on Artisanal Sourdough Toast with a Sprinkling of Freshly Milled Hedgehog Spines served on a Mess Kid Hand Carved by Traditional Forest of Dean Bodgers from the Keel of A Genuine Sixth Rate Battleship in some teeth-grindingly up-to-the-minute pop-up bistro.  Which, as I understand it, is the forfeit.  :)

Quote from: OZPAF
Black pudding? The staff of Lurker Industries deserve a reward surely. :)
The staff at Lurker Industries have been known to cut up very, very rough when the canteen has been unable to provide Black Pudding.  In one now notorious incident the the company lost 3 days production because the staff walked out over this very issue. You can be sure that Mrs Gordon, Canteen Head Cook, is now extremely careful to ensure there are adequate stocks.

Quote from: OZPAF
That's a fine drawing instruments set ... and my set is nowhere near as good!
I expect my drawing instruments have seen rather less active use than yours so perhaps not surprising? :)


Title: Re: Junkers 87 B-2/R-2
Post by: DavidJP on February 10, 2020, 01:15:52 PM
I always coveted those sets of drawing instruments as a lad but never did any of that kind of thing so my desire went unsatisfied.

I think it was Victoria Street in London that contained many shops that sold them and their window displays meant I spent hours admiring seemingly huge cases with dozens of those wonderful instruments in them - quite why any draughtsman would need about 100 different instruments I never did understand.  They were mainly German I am sure and this was, looking back, a bit surprising, because the War had not long been over so how they arrived here is somewhat of a mystery.  They were absolutely beautiful.  Now all the skill and artistry is gone - just touch a few buttons on a computer and stand back for ten minutes of so.  I used to watch them in the engineers office at a place I worked once. Shame, but I suppose anything goes in the name of progress.

But Lurk that is an exceedingly nice Stuka. Don't worry about the siren - they made an awful racket.  I don't think you will have any problem with duration... is there anything in the rules about launching from 6 or 7 storeys up?   You could get a very realistic flight.   


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on February 10, 2020, 01:53:01 PM
Quote from: DavidJP
.... is there anything in the rules about launching from 6 or 7 storeys up?   You could get a very realistic flight.  
A charabanc from the Lechlade, Fairford and District Motor Traction Co. has been engaged to transport the flying staff to Sutton Bank when suitable weather for flight trials presents itself, but that's between you, me and the gatepost; the CD would have an absolute fit if he found out.  ;)

Quote from: DavidJP
Now all the skill and artistry is gone - just touch a few buttons on a computer and stand back for ten minutes of so...
Indeed, but then again you don't get numbskull mistakes such as rectangular instead of oval frames, see above, nor bad cases of "wobbly stringer" as seen in the Keil Kraft Minimoa and you can run off multiple, accurate, copies of a plan without the distortions and blurring that creep in over multiple of generations of photocopying so it's not all bad. Having said that it is still quite satisfying to draw up bits of plan "properly".

Thanks for the compliment, does the ego a power of good.  Now, I really must sort out an appointment with my hatter, this hat has become unaccountably tight, and see about getting those Boardroom doors widened. :)



Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on February 14, 2020, 04:09:47 PM
The air here turned a very, very, very deep shade of blue here tonight.  Now if this had been the result of a flying incident I wouldn't have been angry at all, disappointed?, sad? yes, but because it was my damn stupid clumsiness in letting something slip from my hands....

Stab braces now fitted.

I was joking with Abl about hammering the elevator mass balances out of lead, but that's looking less and less like a joke.  I've managed to take somewhere between 0.4g & 0.5g out of the nose by removing the piece of sheet inside the front that was intended to take any nose ballast that might have been required, hah!, and drilling a 3.5mm hole into the back of the nose block.  No dice.  Even with stab braces in place it still balances just on/in front of main spar and test glides onto the bed have no glide about them - noses straight in.  Take the noseblock off and the glides aren't bad.  Green goo on toast here we come.  *sigh*

For info.
Fuselage et al.           25.95g
Noseblock assembly     7.25g

The prop has already been balanced, but I'm wondering if there's any point in shaving it down a bit more.
ETA. Probably not.  An unbalanced prop of the same sort tips the scales at 2.5g.

To end on a positive note I borrowed the 4 strand 3/32" motor from No. 5 and it's a surprisingly easy job to fit the motor.  I was a little concerned given the lack of room in the fuselage that it might be a bit of a fight.

ETA.
Also thinking about making up a new spinner & prop assembly to seeing if I can make a lighter one as well as stripping the paint off the nose-block and repainting with the new yellow as the dud pot lead to many more coats going on that ought to have been necessary.


Title: Re: Junkers 87 B-2/R-2
Post by: Andy Blackburn on February 14, 2020, 05:18:43 PM
I think you're going to have to move the rear peg back a bay or two. Failing that, there are three options:
  • Add tail weight, or
  • Add some more negative tailplane incidence, or
  • Man up and order some Avocado on Toast...

A.

P.S.
And don't think I didn't notice the Sutton Bank Subterfuge. You want to watch it on those hilly roads, very dangerous, they are. Particularly the ones that are mined...


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on February 14, 2020, 05:30:24 PM
It's tail weight or nothing.  The stab. is well and truly fixed and moving the peg back is a non-starter for two reasons.  First and insuperable is the fact that the frame 9 is solid.  Even if it were open there'd be no room to get a stuffing stick in which is, partly, why 9 was made solid.  The other reason was I didn't think open frames 9 & 10 would be sufficiently robust.

I don't much care about having to eat the green goo, but I am deeply, deeply narked that it's not going to fly well and I am sorely, sorely tempted to bin it as a bad job.


Title: Re: Junkers 87 B-2/R-2
Post by: OZPAF on February 14, 2020, 10:48:07 PM
Don't do that Lurk - you have put too much good work into this model. If the tail plane is glued on with PVA I would suggest considering removing it by painting the glue line with water using a small paintbrush. When the glue turns a milky white it can be removed by gently twisting fore and aft and levering up and down. This should remove it with minimal damage if any at all.

I would then incorporate a adjustable elevator - which will help move the CG back. The new Cg withe tail resting in place(not glued) can be checked and if necessary weight added to the fuselage inside under the tail.

The elevator will give you the option of adding a bit more decalage if necessary.

John




Title: Re: Junkers 87 B-2/R-2
Post by: flydean1 on February 14, 2020, 10:48:57 PM
Don't move the rear peg, whatever you do.


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on February 15, 2020, 01:32:21 AM
Quote from: OZPAF
If the tail plane is glued on with PVA...
Unfortunately it's not. I'm going to try the brute force and ignorance approach first, i.e. tail weight although adding it feels like far more of a defeat than having to eat three portions of green goo on toast.

flydean,  moving the peg back isn't an option short of starting from scratch and given that it's taken nearly 5* months to get to this point then, short of it not flying at all that's not going to happen.

Now what is it they say about pride and falls?  :)

Cheers,
A still slightly hacked off Lurk.


*More like 10 if you include the prep work.


Title: Re: Junkers 87 B-2/R-2
Post by: Andy Blackburn on February 15, 2020, 02:38:45 AM

> and I am sorely, sorely tempted to bin it as a bad job.

Don't do that, whatever you do - whatever legal objections might have been submitted in a last attempt to claw back some points, it's very far from a bad job. I think it looks excellent.

Firstly, I'd try installing a slighty bigger motor which might move the c.g. back a bit - my (admittedly rathere heavier) VMC Spitfire needed 4 strands of 0.100" on a 6" VMC prop.

Secondly, If you have to add tail weight, it probably won't be very much so I'd try it to see what happens.

If that hasn't fixed the issue to your satisfaction, then all is still not lost; if you've glued the fin on with balsa cement or CA then it should be possible to soften the joint with either thinners/dope or CA debonder, in which case I think the best approach is to build a new fin and stabiliser (with a little more negative incidence) and moveable control surfaces as suggested by OZPAF. Even if you've epoxied the fin on, it might be possible to cut through the glue line, given sufficient patience.

Even if you have to add tail weight, it'll still be quite light for a KK Stuka (which, in spite of recent protestations, is what it started out as).

A.


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on February 15, 2020, 03:22:00 AM
This morning's works have managed to cut the nose assembly weight further from 7.25g to 6.88g.   Careful, very careful, removal of the spinner disk, and opening out of the existing void in the back of the nose block.  This has pushed the balance point back a bit, not much and nowhere near 1/3+ of root chord, but enough to be noticeable and it will reduce the amount of tail weight needed so better half a loaf.

abl> ... if you've glued the fin on with balsa cement or CA...

Aliphatic & CA.  Aliphatic to give me enough time to tweak alignment & touched up with a few dabs of CA to give a solid joint when the aliphatic has cured because I've had 1/16" fins work loose using aliphatic alone.

abl>  ...my (admittedly rather heavier) VMC Spitfire...

What was its eventual weight sans motor?   One finds the forum search a little less than helpful.

abl> ...best approach is to build a new fin and stabiliser (with a little more negative incidence) and moveable control surfaces as suggested by OZPAF

Aye and it would be worth doing simply to improve its chances of flying well indoors, but at 5 months or so into the build phase I'm not sure I can face another block of significant (for me) effort.


Title: Re: Junkers 87 B-2/R-2
Post by: Russ Lister on February 15, 2020, 06:08:38 AM
You started this build on such an 'up' .... you can't let it finish on a low!  :) I hope that the Kit Scale Police haven't got to you .... I'm thinking James Cagney in Angels With Dirty Faces! ::)


Title: Re: Junkers 87 B-2/R-2
Post by: Invader3 on February 15, 2020, 06:59:11 AM
Come on, Lurk - you've got all of us watching in the background hooked on this build! You can think of something!
And if it means not eating the "A" word, even tail weight has got to be worthwhile, surely!!

Seriously, I'm sure I'm not the only one who's been watching and learning and enjoying the banter - please don't give up now!

regards,
John


Title: Re: Junkers 87 B-2/R-2
Post by: LASTWOODSMAN on February 15, 2020, 07:33:23 AM
Hi Lurker.  I echo Newbie John's sentiments also.   I smashed up five nice bipes trying to get them to fly,  and each one took 4 months to build, so I am just keeping them for display.   I can relate, though.   I hope you don't bin it.

LASTWOODSMAN
Richard


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on February 15, 2020, 07:38:24 AM
After much imitation of a flock of decapitated Gallus gallus domesticus and not a little rummaging around for the sackcloth and ashes by the design and assembly staff at Lurker Industries a plan has been decided upon.

1. No major structural revisions or redesign at this stage.
2. Test fly with tail weight to see whether or not item 1. is worth doing.
3. In the meantime get sloshed on the best sherry the Directors can turn up.

Or...
After a little further nose weight reduction effort balance is achieved at 50% +/- of root chord with 3.6g of tail weight.  Which gives a likely initial weight sans motor of 36.5g.  I started the build hoping for a ballasted weight of 35g or under so a significant overshoot.  I'm (desperately) hoping that the CG can be shunted a touch further forward to knock a few tenths of a gramme out of the tail weight.  A 14", 4 strand 3/32" motor is about 2.9g so I'm looking at a flying* weight at best a breath under 40g and possibly well over depending upon motor used.

*Now there's optimistic.

I was expecting No. 18 to be heavier than K5083 as there's significantly more additional detail and if it had been, as usual, tail heavy it would have required additional ballast up front so perhaps given the changes made this is about the best I could have expected.

For comparison
My K5083 last flew at 31.5g
Abl's Blue PR VMC Spitfire went into proving at 32.8g
Jack Plane's Pink PR VMC Spitfire at 31g ditto.
All weights without motor.

If No. 18 shows signs of flying even moderately well as it is then a return to the drawing board will be justified otherwise it'll be written off as a monument to my hubris and I will with, great reluctance, a heavy heart and a packet of indigestion remedy by my side, eat some green goo on toast. :)

Quote from: Russ Lister
You started this build on such an 'up' .... you can't let it finish on a low!  :) I hope that the Kit Scale Police haven't got to you .... I'm thinking James Cagney in Angels With Dirty Faces! ::)
Just a bit disappointed that it looks like it's going pear shaped at the very last step. I'll get over it.

Perhaps, given the potential for a,  metaphorical, shooting down in flames "White Heat", "Made it, Ma! Top of the world!" might be a more appropriate reference?  :)

Quote from: Newbie_John
...please don't give up now!
Don't worry, the staff at Lurker Industries have recovered a measure of equanimity and composure and will not give up until it is proved beyond doubt to be an utter Meleagris gallopavo.  :)

Quote from: LASTWOODSMAN
I smashed up five nice bipes trying to get them to fly,  and each one took 4 months to build,
Ouch.  Rather puts my pitiful woes with this one into perspective.


Title: Re: Junkers 87 B-2/R-2
Post by: Indoorflyer on February 15, 2020, 10:37:40 AM
Lurk, what is the wing area? If you end up with a flying mass of 40 g, the incremental increase spread across that big wing may not be so bad after all. What wing loading would that give you?


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on February 15, 2020, 11:15:30 AM
Quote from: Indoorflyer
Lurk, what is the wing area? If you end up with a flying mass of 40 g, the incremental increase spread across that big wing may not be so bad after all. What wing loading would that give you?
Dunno. Too scared to work it out.  :)

ETA.
Using all my fingers and toeses, ignoring the wing tips and underestimating the area a bit more to allow for an/dihedral I get a single wing area of 1.77dm2 (3.54dm2 total) which at 40g gives a wing loading of 11.3g/dm2.

Further ETA.  Using http://www.ef-uk.net/data/wcl.htm which does the arith. for you that comes out at 3.7oz per square foot or a wing cube loading of 5.9.

Dunno about anyone else, but that seems worryingly high to me.

Now, given that MrsLurker does all the household accounts because, despite having done A level maths and Stinks to degree level with a garnish of Physics, my arithmetic is utterly attrocious* I would take that figure with a whole bushel of salt.

Lurk.

*True story.  Maths class.  Teach is dishing out the jotters having marked the homework when he comes to mine, "Boy Lurker!", "Sir!", "What's three threes?" Quick as a flash I answer, ... "Six"  Whereupon I am struck upon my, non-bald** but utterly dense mid teenage, bonce.

**Hard to believe I know, but it is true, there once was hair upon this hairless pate. I have photographic evidence from a time before Photoshop.


Title: Re: Junkers 87 B-2/R-2
Post by: Andy Blackburn on February 15, 2020, 01:14:40 PM
> Dunno about anyone else, but that seems worryingly high to me.

Executive summary : It'll be fine.

Arithmetical Evidence:

You can work out the wing area from Wikipedia; since we know that the KK Stuka is 19" span and the full size spans about 45 ft 3.5 in, the scale factor must be ((45 x 12) + 3.5)/19 = 28.6 . The wing area of the full size is about 343.37 sq ft, so the area of the model wing must be (area/(scale-factor x scale-factor)) = 343.37/(28.6 x 28.6) = 0.419 sq ft =~ 60 square inches. I think the difference is partly because the "standard" wing area always includes that bit of the wing covered by the fuselage.

That means that the wing loading at 40 grams is 40/0.419 = 95 grams sq ft. The equivalent figure for my VMC Spitfire at 46 grams was 113 grams sq ft. I think the best that managed on about 800 turns was about 27 seconds.


Title: Re: Junkers 87 B-2/R-2
Post by: billdennis747 on February 15, 2020, 02:16:42 PM
I once worked in agricultural research and we had a machine that measured area. You fed grass leaves through it and up came the area. I seem to recall once cutting out a paper  tailplane of a model I was worried about and feeding through the machine. Eventually I realised that small tailplanes are rarely a problem and stopped worrying. Only a Ryan S of St L  was tricky and a Halberstadt impossible


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on February 15, 2020, 03:01:56 PM
Quote from: Andy Blackburn
... the area of the model wing must be (area/(scale-factor x scale-factor)) = 343.37/(28.6 x 28.6) = 0.419 sq ft =~ 60 square inches.
 I think the difference is partly because the "standard" wing area always includes that bit of the wing covered by the fuselage.

Working back from the area taken from the plan and approximating 1 sq ft to 9dm2 I get 0.4 sq ft for the wings ignoring fuselage and 0.42 sq ft treating the area of the fuselage as a part of the lifting surface.  Point 4 gives an upper limit of 100g/sq ft.

Quote from: Andy Blackburn
...equivalent figure for my VMC Spitfire... 800 turns was about 27 seconds.
You have no idea how just how cheering your figures are.  If I can get anything over 20s from this I'll be very pleased. However...

... I think I need to go back to the plan and see what can be done to limit the tendency to nose-heaviness.  With that chin and UC I think it's always going to tend that way, but a few things strike me that can be done without destroying the look of the end result.

1 - Lose the infill on the nose forward of the cockpit.  If you scallop the frames* you'll still get a decent curve without it. That should knock about 0.05g/panel out forward of the CG. Saving somewhere between 0.7 and and 0.9g.

2 - Don't try for the open rad. inlet.  It doesn't work and adds the dead weight of the ply reinforcer.

3 - Don't fit a ballast plate.  There's plenty of space on the back of F2, which is hidden by the rad. gills, for any ballast that may be needed.

4 - Use 1/32" sheet for the spinner plate and cut it out when the nose assembly is completed.  You could use 1/16", but 1/32" will be easier to remove without damaging anything

5 - Lose the short doubler strips fitted to provide a hardpoint for the exhaust stacks.  They aren't necessary.  The top line of the exhaust stacks stack coincide with a stringer run.  See the pic.

6 - Build voids into the noseblock laminations.  Amusingly enough I considered doing this to start with but then I thought, "Nah it'll be tail happy and I'll need the weight up front."  Hah!

7 - Use a square nose plug, 12mm nominal as per VMC's MfM kits, rather than the rectangular plug I used.  The rectangular plug was because I had originally planned to fit a thrustline adjuster.

8 - Don't use so much paint on the nose block.  Yeah, I know obvious, but there are more coats on this than there should be because of that dud tin of yellow.  I may yet sand back and repaint. It won't save a lot, but it will save something.

All told I think those changes would be good for a reduction of at least gramme forward of CG with a corresponding (hopefully larger) reduction in tail weight.  If my estimate is any good at all that would bring the flying weight with down to about 38g with a 14", 4 strand 3/32 motor which gives a wing loading of ...

  10.8 g/dm2
  3.4 oz/ sq. ft.
  ~90 g / sq. ft.

Another marginal weight reduction might be to cut voids in the two in-most UC leg lamina, as per the central ply core. That would probably net another 1/5 to 1/4 g, again forward of the CG.

Cheers,
Lurk.

*I meant to say some time ago. I scalloped the frames on this build (a Lurker Industries first) and was very pleased with the result when it came to covering.


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on February 15, 2020, 03:08:30 PM
Quote from: billdennis747
You fed grass leaves through it and up came the area.
Now that's interesting.  How did it work?  Analogue or digital computing?


Title: Re: Junkers 87 B-2/R-2
Post by: billdennis747 on February 15, 2020, 03:19:33 PM
Quote from: billdennis747
You fed grass leaves through it and up came the area.
Now that's interesting.  How did it work?  Analogue or digital computing?
This was back in the 70s. I think it had a row of tiny lights and receptors that recorded when light was blocked off, linked to the speed of the feed through. It was a Heath Robinson device, probably made in the workshop. It was effective though


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on February 15, 2020, 03:26:10 PM
Quote from: billdennis747
Quote from: TheLurker
Quote from: billdennis747
You fed grass leaves through it and up came the area.
Now that's interesting.  How did it work?  Analogue or digital computing?
This was back in the 70s. I think it had a row of tiny lights and receptors that recorded when light was blocked off, linked to the speed of the feed through. It was a Heath Robinson device, probably made in the workshop. It was effective though
Ahh.  I like that.  Lot to be said for straight-forward solutions.


Title: Re: Junkers 87 B-2/R-2
Post by: kkphantom on February 16, 2020, 05:37:08 AM
Have you considered using a balsa prop? Certainly lighter and probably more efficient than a plastic one.
Gary


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on February 16, 2020, 09:48:08 AM
Quote from: kkphantom
Have you considered using a balsa prop? Certainly lighter and probably more efficient than a plastic one.
Very briefly.  I have always considered prop. carving to be deep magic and far, far beyond my wood-butchering skills.  There's a reason I use laminations so very much for all my builds. :)

Just out of interest what would be a likely pitch and diameter to replace the 6" plastic paint-stirrer used for this build? And what sort of weight would you expect it to be?  For reference an unbalanced 6" VMC supplied prop. averages 2.5g.  I've never bothered to weigh a balanced prop. There never seemed to be any point with most models being tail rather than nose heavy.

In other news the final planned bits fitted;  the elevator mass balances.  A tweezers & beta-blockers job and one I'm glad I didn't try to cram in last weekend.  Fiddly? I'll say. They're slightly overstated, too deep, but I'm content to let that ride.

Now a case of cutting some matching lead tail-weight (*sobs*) to glue just ahead of the rudder post, making up a fresh motor and then waiting for reasonable trimming weather.

Given my stocks of strip I'm planning a 14" to 15" 4 strand 3/32" (0.094") as used in my Camel which flies at about 42g.  Anyone care to offer an opinion as to the wisdom or folly of this choice?

Lurk.


Title: Re: Junkers 87 B-2/R-2
Post by: Andy Blackburn on February 16, 2020, 11:08:31 AM
> Given my stocks of strip I'm planning a 14" to 15" 4 strand 3/32" (0.094") as used in my Camel which
> flies at about 42g.  Anyone care to offer an opinion as to the wisdom or folly of this choice?

Personally, I'd go perhaps a little bigger for outdoors. Maybe 4 strands of 100 or 109 thou...?

A.


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on February 16, 2020, 12:55:47 PM
The stores wallahs tell me that all they have to hand are the items listed below and given the expenses incurred for both materials and overtime on this project already discussed in these memoranda (https://www.hippocketaeronautics.com/hpa_forum/index.php?topic=24583.msg250168#msg250168) it is unlikely that Mr. Chisholm will approve any further expenditure.  

1/4"    0.25
3/16"   0.19
1/8"    0.125
3/32"   0.09
1/16"   0.063

Or...

OK, proposed motor is a little under-powered but not ludicrously so for initial flight trials.  If it gets through the 12 second barrier, a story soon to be rendered for the Kinema by director David Lean and starring many of Britain's finest actors and actresses with staff from The Lurker Industries Kinematography Club in supporting rôles, then we shall explore the possibilities of an uprated motor.


Title: Re: Junkers 87 B-2/R-2
Post by: Rhys on February 18, 2020, 01:03:56 PM
Wonder if anyone has ever employed a small device wheras you could check the fuselage nose/tail balance as you build?  A simple frame with withdrawing metal pins of size on each side. Just a feeble thought.

 Sturzkampfflugzeug looks Fantastisch!!!

Cheers
Rhys


Title: Re: Junkers 87 B-2/R-2
Post by: Graham Banham on February 19, 2020, 05:32:55 AM
Lurk: apologies if i’ve missed something but have you actually tried to fly it other than bed glides (which will usually tell you nothing in practical terms)?

You may be worrying needlessly as the solution could be as simple as a couple of acetate tabs bent up on the tailplane, or nothing at all once it’s powered up.


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on February 19, 2020, 11:39:49 AM
Quote from: Rhys
...looks Fantastisch!!!
Aye, well.  Until and unless it flies it doesn't matter how good (or bad) it looks, and I'm still deeply narked I dropped summat on the stbd wing, nonetheless the compliment is appreciated.  Thanks.

Quote from: Graham Banham
...have you actually tried to fly it other than bed glides...
I drew back the curtain, to see for certain, what I thought I knew... aye, it's still blowing half a gale and raining stair-rods, or καρεκλαποδερα for the more cosmopolitan members of the parish, and forecast  to do much the same for the foreseeable.  Nope  :) 

It's a teeny bit annoying; had I managed to finish the build anywhere near my planned end date I would have had 2 or 3 days of calm, warm(ish) still weather towards the end of Jan. to test it.

Short of removing and resetting the stab with more neg. incidence the acetate tab idea is well worth considering.  Ta.


Title: Re: Junkers 87 B-2/R-2
Post by: Squirrelnet on February 19, 2020, 01:39:24 PM
Quote
Short of removing and resetting the stab with more neg. incidence the acetate tab idea is well worth considering.  Ta.

or even adding a gurney flap to the top surface of the tail ???

Personally I still think your black pudding is safe....


Title: Re: Junkers 87 B-2/R-2
Post by: Andy Blackburn on February 19, 2020, 04:02:30 PM
...

Personally I still think your black pudding is safe....

It pains me to say so, but I agree. I think you've got this one in the bag, Lurk. Protests notwithstanding, of course.

A.


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on February 23, 2020, 02:55:52 PM
The Met. wallahs keep piling on the misery here.  Absolutely no chance of flight trials for heaven knows how long so I've been getting on with correcting the "dud" formers so that the after part of the fuselage looks right.  Well, less wrong.

While I'm here.  It has been suggested, see discussion above on nose-heaviness, that the peg position be moved back to bulkhead No 9.  Now this strikes me as a nice idea, but given the width of the fuselage at that point I'm not sure that it's terribly wise.  It looks to me that F9 can't be opened up enough to give good access for a stuffing stick without making everything too fragile to take a fully wound motor.  See the progression pic for F9, the test formers are laid on a 1" grid

Question is; if, hypothetically, you were building a model to this plan would you risk opening up F9 so that the motor peg could be moved back?

Pics. 
Progression through formers to "correct" shapes,  test stringer fitting to be sure that the lines are OK and the fuselage of the current incarnation showing the boxy aft section for comparison.


Title: Re: Junkers 87 B-2/R-2
Post by: Russ Lister on February 23, 2020, 03:57:40 PM
Quote
The Met. wallahs keep piling on the misery here.  Absolutely no chance of flight trials for heaven knows how long so I've been getting on with correcting the "dud" formers so that the after part of the fuselage looks right.  Well, less wrong.

We should contact Kew Gardens ..... get them to grow some genuine Keilkraft grass under glass. We just need to persuade them of the need to fly model aeroplanes over it. Could happen ...... currently a higher probability than flying outside.


Title: Re: Junkers 87 B-2/R-2
Post by: flydean1 on February 23, 2020, 04:34:07 PM
Never, ever, ever, ever move a peg back.  I will cause far more problems than it will solve.

Sort of like the government.


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on March 19, 2020, 03:56:46 PM
His Honour the Judge Herr Baron von Markovitz having retired to chambers to consider the protest, below, lodged by a firm of low scoundrels, rogues and ambulance chasers on behalf of Testwood Towers has handed down his decision. In summary he finds in favour of Lurker Industries.  His full judgement his given below.

Quote from: Messrs. Grabbit, Scuttell & Dashe
Dear Sirs,

My client has directed that a protest be submitted as he feels that the board of Lurker Industries has identified a (regrettable) gap in the rules; my client informs me that the member of staff responsible for drafting the rules will of course be subject to the usual sanction.

As you will no doubt be aware, the Ailerons and flaps of the Ju 87 sit below the wing trailing edge and the standard Keil Kraft plan mirrors this arrangement by using small pieces of 1/16" square to fit the flaps to the wings, as shown in the bottom right-hand corner of the plan.

However, the most recent picture of Lurker Industries' Ju-87 build appears to show the ailerons and flaps attached directly to the trailing edge of the wing.

Now, obviously, this departure from the plan should be covered by rule #4 ("If the judge considers that a particular change is detrimental to the overall character of the model, no points will be awarded for that change.") because it clearly changes the overall look and character of the model, but my client considers that this sanction is not sufficient.

The reason for this unusual and forthright view is that my client has submitted the pictures to a number of independant aerodynamic analysts, the unanimous opinion of whom is that moving the ailerons and flaps up to the trailing edge will confer a significant aerodynamic advantage by reducing the drag associated with the original 1/16" wide slot, thus making the achievement of a minimum 12 second flight even more likely than it already is.

My client considers that a fair and reasonable penalty for such a gratuitous change would be:
For each surface that has been moved (6 in all), remove 10 points from the total of penalty points that have already been awarded, and
For each surface that has been moved (6 in all), add 2 seconds to the minimal duration requirement.

I await the judgement of the court with some degree of interest.

sincerely

J Grabbit (acting for the board of Testwood Towers Operational Research)

Quote from: Press Office Lurker Industries
Mr Barnes-Norway, after much careful and considered thought had the following to say, "Awa bile yer heid..."  and he, most unusually for a Sunday afternoon, not having yet had his accustomed sherry.

After a little further thought (and a fortifying glass or two of sherry) he went on to say, "If there is a gap in the rules then no rule can have been infringed so no sanction is applicable. " he also went on to point out that the flaps are attached in a similar manner to that indicated in Mr. Hatfull's plan; split cocktail stick replacing 1/16" balsa strip and that TTOR's ambulance chasing shysters should be,  to use a delightful American phrase, "Run out of town on a rail."  Nor does this trivial difference represent a change to the overall look or character of the model.  The enclosed photographic reproduction is presented as evidence of adherence to the spirit as well as to the letter of the rules as originally drafted.


Quote from: His Honour Baron Von Markovitz
Gentlemen,

I've now pondered the matter for the requisite period of time, and my judgement in the matter of Alterations is:

Ratio Decidendi: in favour of Lurker Industries.

Obiter Dicta: if Lurker Industries fails to achieve the minimum flight time as previously agreed, then the above judgement is annulled and Testwood will be deemed the winner.

The losing party will need to provide photograph evidence of his consumption of the green goo.

No judgement is given as to costs (i.e. both parties will carry their own costs) and no leave is given for either party to appeal.

HH Baron Von Markovitz

My, but I am cheesed off with this blasted weather.  Doesn't seem to have stopped raining or blowing half a gale since mid January.  All the fields here are quagmires if they're not actually under water.  Beginning to wonder if I'll ever get this thing tested.


Title: Re: Junkers 87 B-2/R-2
Post by: Andy Blackburn on March 20, 2020, 05:09:18 AM
Bah...

I am, however, advised that I should ask for a Judicial Review from the Lord Chancellor.

And I still think that a mere 12 seconds will be easily achiveable.

A.


Title: Re: Junkers 87 B-2/R-2
Post by: OZPAF on March 21, 2020, 04:53:17 AM
At a indoor site perhaps?

John


Title: Re: Junkers 87 B-2/R-2
Post by: Jack Plane on March 21, 2020, 06:32:28 AM
Or a decent slope...?  ;)


Title: Re: Junkers 87 B-2/R-2
Post by: Andy Blackburn on March 21, 2020, 11:33:51 AM
That settles it - I'm going for a judicial review.  :)


Title: Re: Junkers 87 B-2/R-2
Post by: TheLurker on March 21, 2020, 12:55:21 PM
Quote from: OZPAF
...indoor site perhaps?
Alas.  As of last night all "gymnasia" are closed.  I expect that to include sports halls as well and even if they weren't I should imagine any that are attached to a school are unlikely to be available following the closure of schools on Friday.  I do know that the Newbury hall (a school building) used by some members of this parish has shut up shop of its own accord.

Quote from: Jack Plane
Or a decent slope...?  ;)
Sutton Bank has been considered, but White Horse hill is considerably nearer.

Quote from: Andy Blackburn
That settles it - I'm going for a judicial review.  :)
Hmmm, now... who was it tried to bribe His Honour the Judge with spirituous liquors? Hmmm?  :)


Title: Re: Junkers 87 B-2/R-2
Post by: Jack Plane on March 21, 2020, 03:48:22 PM

Hmmm, now... who was it tried to bribe His Honour the Judge with spirituous liquors? Hmmm?  :)


Indeed a bottle of rather fine single malt turned up on the doorstep with a note saying it was from Lurker... but I rapidly saw through his ruse!


Title: Re: Junkers 87 B-2/R-2
Post by: Andy Blackburn on March 22, 2020, 04:14:07 AM
...
Quote from: Andy Blackburn
That settles it - I'm going for a judicial review.  :)
Hmmm, now... who was it tried to bribe His Honour the Judge with spirituous liquors? Hmmm?  :)

Bribe? Me? Surely not.  :)

A.