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Outdoor Free Flight Forum => Free Flight Scale => Topic started by: Prosper on December 22, 2017, 09:29:12 AM



Title: Little [s]Brown[/s] Natural metal Jug.
Post by: Prosper on December 22, 2017, 09:29:12 AM
⌠ Hi gang. Ho! ho! ho!

  Hi gang. Bahhh, humbug. ⌡  Take yer pick.

This project was started as a companion for my "Flying Scale Models of WWII" Grumman F6F model. 1/24 scale for rubber power.

The fuselage will use the same building method as the F6F, and the wing uses the style of S&T wingbuilding I adopted from early days. Ultimately there's little left of the 'FSM of WWII' design - I guess that's why I rarely build from other people's plans: I can't stick to 'em more than a second. I respect the I. E. Coleman plan nevertheless: scale tail area, scale dihedral and scale wing thickness.

The P-47 wing aerofoil is listed as the Republic S-3 which pleased me because it's thin, but it soon became obvious that this was wrong: I guess it should be listed as "S-3 mod", because my best measurements from pictures give a 14% root thickness and about 10% at the end of the aileron. The 'distinguishing feature' of the foil is its very sharp nose.

I'm no geometrician but it seems to me that for an elliptical wing to maintain a consistent thickness-to-chord ratio (or a consistently changing t/c ratio) along the span, the wing must curve in front elevation as well as in plan, like the Spitfire's wing. The P-47's wing appears to have constantly tapered spars. This precluded using an image-editor simply to resize the scale root rib outline in order to obtain the outline of each subsequent rib. Instead I had to make an EPS wing, on which I marked rib stations and spar positions, before slicing it to give me the rib shapes. With hot-wire cutter and a coarse sanding block this didn't take long.

The ribs are medium C-grain 0.8mm balsa, the spars are 0.8 x 2mm straight grain, the L.E. sheeting is light 0.4mm straight grain and the T.E. is fairly hard 1.6mm C-grain 6mm wide.

Stephen.



Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Prosper on December 22, 2017, 09:32:58 AM
Here's a start on the fuselage. It took some time to draw fuselage former outlines that I was happy with. They called them Razorbacks for a reason - the dorsal spine is more concave and with a much sharper spine than in the FSM of WWII book. In fact it looks like a cutthroat razor :).

I drew the outlines direct onto thin card then cut out the centres.

The laminations are from light straight-grain balsa ≈0.3mm thick, cut into 2mm strips (pic 1). Strips (five in this case) can be coralled into the template (pic 2). This is the hardest bit because the individual strips want to escape back to the wild and it's easy to snap one accidentally whilst herding. Using tape helps but taping un-CA'd strips is a bit risky, again because of the strips' fragility.

Pic 2 shows the stage where I've got one single drop of CA onto the lowest part and marked that point. Reference markings on these frames are necessary during fuselage construction. Things become progressively easier now; pics 3 and 4 show how you can work round the template snugging the laminations to it and dropping single drops of thin CA at intervals. Once the strips are bonded, tape can be used with less caution.

Pic 5 shows the frame ready for release. It might look as if it's joined at the top but it's not: my strips weren't quite long enough. I'll have to insert an extra piece at the top or use some other bodge. Joining ends to make a continuous loop does present a challenge: with the F6F I cut the ends into long opposing wedges, but achieving a good joint this way is a task. Since all these frames will end up with extra structure (cross-braces etc) I may simply butt-join square ends where I know they'll be reinforced with extra structure.

Once released from the template the frame can be liberally dosed* with thinnest CA on its other face then re-dosed on the top face (because it's only been 'spot-welded' hitherto) (pic 6). Weight after a gentle sanding is 0.2g but it will need some additional bracing.

A more orthodox method is simulated in pic 7 where the template is pinned to a non-stick surface and pins keep the laminations next to the template. The first method is clearly quickest. I've used both. In the latter case I run round the thin card template with a thumbnail to raise the edge somewhat. This makes a more secure nest for the laminations.

*the CA will "smoke off" as it runs along and into the laminations so keep your nose well clear!

Stephen.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Prosper on December 22, 2017, 09:33:32 AM
pic 7


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Crabby on December 22, 2017, 10:26:08 AM
Superb craftsmanship going on here. Are you going for the big nasty 4 bladed blender up front? I am thinking those fuse formers would be easier on your handing if they were basswood. You don't want a fabrege egg to deal with.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: strat-o on December 22, 2017, 10:41:18 AM
Most graphic editors worth their salt will let you scale each axis independently.  If you start with a basic airfoil and scale the x to the chord and the y to the thickness you should achieve a usable airfoil for any occasion.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Prosper on December 22, 2017, 12:00:20 PM
Interesting points, Crabby and Marlin. I use two image programs, one ancient and one modern. The modern one scales the axes independently if desired, and I think that in the case of very small deviations 'tween x and y as would be the case here, I'd have been more sensible to derive the rib shapes that way as you suggest. I got it into my head back in the mists of thyme that this wouldn't work because each one of a large number of rib stations would need to be rescaled in proportion to their place along the chord to get a faithful rendition of a given (but fatter or thinner) section. I don't honestly know if that's right, but it put me off scaling axes independently ever since I dreamed it up.

The Fabergé egg concern is a very valid one Crabby, and when I made the formers for the F6F I feared the same; they seemed too flimsy. I was less poetic about it though - no Fabergé egg, just "they're way too $(^&O* weak!" In fact though, s'long as they're strengthened adequately across the beam they're fine. The one I really stiffened up was the one where I'd hold the model for launching; coincidentally the one that holds the motor peg. It'll be the same for this old bucket I hope. Yayss, four blades - naturellement, M'sieur ;D.

Hot off the press is this F9 (the smallest). I had to roll the strips slightly (i.e. compress them from the inside using a pen as a rolling-pin) to get them round the small-radius curves. I don't like this because it inevitably crushes the wood to some degree, but never mind. To get the ends joined I overlapped them before they were CA'd and sliced right through: youc'n see the razor slice into the white card. Then when butted together they needed a thin packing piece to make the join. I made the outlines of the rear frames increasingly oversize as I went back, anticipating that the stringers will be sanded thinner as they go back. The "1.0" scribbled on the template means the stringers should be 1mm thick at this point.


Stephen.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: -John- on December 22, 2017, 11:51:50 PM
Your aerofoils look spot on Prosper. The P-47 is a nice subject as the full size ones are quite large(The Spit looks somewhat small in comparison).


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Work In Progress on December 23, 2017, 04:37:26 AM
It is indeed a monster, for a single-seat single piston engined fighter. And a highly charismatic one too.

The wing is not really elliptical in the sense of its underlying design adn construction logic. Structurally each wing panel consists of two tapered trapezoids, the chordwise boundary being located at the flap/aileron dividing line. The leading edges are of course basically straight and the straight-edged rear boundaries of the two trapezoids are the mating surfaces for the flaps and ailerons. The curvy trailing edges of the wing are all fudged into the structures of the ailerons and flaps.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Marco on December 23, 2017, 06:57:46 AM
 I am ready in the armchair with my pop corn to watch this great build that is going to come along ! Interesting approach to laminate inside a former, rather than around it.
Marco


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Prosper on December 23, 2017, 10:27:25 AM
C'mon, Marco, you're Italian - surely you can come up with something better than popcorn? Some bruschetta perhaps? :) While following your MC200 thread I may adopt the David JP option of Port and Stilton - since it's Christmas - or maybe some Welsh rarebit with Dijon mustard if the weather gets cold again.

Yes the size of the P-47 is one reason I chose it. I've found 1/24 rather too small a scale for my hands and eyes where detailed all-sheet models of average-size subjects are concerned, but I found the S&T F6F no problem. I want something that flies less well than the F6F (to suit my flying field) and the '47 has less wing area, a big fat fuselage and a four blade prop, so it ought to perform less well. I may well be larding it with paint too.

That's right about the wing but I'm still curious because it seems that with a straight tapered spar, the thickness-to-chord must decrease towards the middle of the span then increase again. I can't see that this would be good aerodynamically.

I finished the basic formers this a.m. These came out much more easily than the F3/F4 I described in earlier posts - partly because they're open-ended but mainly perhaps due to practice. In fact they seemed so easy I made a new F3/F4 to replace yesterday's one, and made it stronger (6 laminations). This 'un weighs 0.3g compared to 0.425g for the un-notched F2 seen in the last picture. The card template for F3/F4 has now been used three times and is still serviceable.

Pic 1 shows how the dry laminations fit into the template pretty closely merely by their own springiness. I got them all fitted like this then did a mass-CA'ing, one after the other.

Stephen.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: strat-o on December 23, 2017, 10:39:28 AM
Hi Stephen.  In case your P-47 requires field assembly, I've located this video for you.

https://www.youtube.com/watch?v=Noqms4AhTJA (https://www.youtube.com/watch?v=Noqms4AhTJA)

Marlin


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: steveair2 on December 23, 2017, 11:53:34 AM
Very nice!  I've been wanting to try this method. Thanks for such nice pictures of process.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Prosper on December 24, 2017, 10:16:35 AM
Thanks Marlin - the ingenuity is fantastic - designing the aeroplane must have been a doddle compared to that. Steveair2, you're welcome.

This is the Jug jig. Now, it's reely important for the jig to be straight and well aligned, and that it doesn't move during assembly. So don't make a jagged Jug jig or jog it.

Stephen.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: MKelly on December 24, 2017, 12:24:50 PM
Jumpin' Jehosephat, that's a jewel of a jiggy jug jig!


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Prosper on December 25, 2017, 10:24:15 AM
;D ;D


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: ironmike on December 25, 2017, 01:18:06 PM
Seriously, MK


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: OZPAF on December 25, 2017, 05:38:01 PM
Another interesting build Stephen - full of different and new(to me anyway) approaches as usual, all very carefully done. The multiple J jig caught my attention as well.
Incidentally I guess you would have sanded the elliptical plan form EPS wing to shape before slicing it with a hot wire cutter?

Merry Christmas and hope you manage some flying in your neighbour's field.

John


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Prosper on December 28, 2017, 11:10:35 AM
Hi John, all the best for 2018. The EPS wing was mostly shaped with a wire cutter to minimise sanding, then I sliced the sections with a razor.  I've been put off S&T wings that aren't constant chord because of this business of deriving accurate rib shapes, but rushing up an EPS wing like this isn't much fuss after all.

The first part of fuselage assembly was to tape the 'keel stringer' to the jig. Next I tacked the front former to the jig and slotted in all the hoops. A good deal of squinting and tapping and muttering ensued, then I removed each hoop to sand it so that it met the keel stringer fairly, reinstalled it, did more squinting, tapping and grumbling, then fixed each hoop to the keel with a dot of CA. The first few stringers took a long while to fix because of all the eyeballing and checking of trueness. After a couple of pairs were in place though the structure had enough stiffness to look after itself pretty much, and adding the others was very quick. I've had to miss out a couple of stringers because of clashes with the spruce uprights of the jig. I'd guessed this would be the case. For the same reason four of the stringers aren't fixed to the rearmost frames yet.

The stern former is missing altogether: I still only have a vague idea of how the tail surfaces will integrate with the fuselage and thought I'd get a better idea when I saw the actual thing in 3D.

There's one frame - F3 - which several stringers  run over without touching. I guess it's slightly asymmetrical. That'll need some packing between frame and stringers. Other than that the assembly looks okay - any slight undulations appear to be well within what a light sanding can make good. Next I shall lift the fus. off the jig and see whether it goes banana shaped. If it does I'll stick it under the tap for a dousing, re-attach it to the jig and let it dry. Come to think of it I may just do that anyway, to clear any stresses out of it.

Incidentally, I should explain the scrambled title of this build, on the offchance that someone might read this who's too young to've been jiving and jitterbugging in the 1940s :). The 'new topic' field doesn't seem to recognise HTML code or it would have read 'Little Brown Natural metal Jug', Little Brown Jug being a swing ditty popularised by the Glenn Miller Orchestra in 1939.

Stephen.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: duration on December 28, 2017, 11:22:27 AM
Prosper;

That's some really pretty quarter-sawn balsa you are using for the jig!  Have you decided that it is time to start using up your stash of good wood? Or are you like me and buy every nice-looking piece of balsa no matter what the weight?

Seriously, nice work. I really enjoy simple solutions to jigs.

Louis (Who has a piece of 20 pound 1/32 with speckled quarter grain that I bought at least 30 years ago---finally found a use for it on the non-flying Samokish F1B wingtip that I made for the 2014 NFFS Sympo cover.)


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: USch on December 28, 2017, 12:01:43 PM
By the look of it Prosper's balsa is between 5-7 lb/ft3.
My heart is bleeding  :(
I'm in the same group as Louis buying every piece of quarter grain I see (actually not to much lately)

Urs


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Prosper on December 28, 2017, 12:42:36 PM
Hi Louis, Happy New Year., and also to you, Urs.

Quote from: USch
By the look of it Prosper's balsa is between 5-7 lb/ft3.

Naaw, much heavier than that; twice as much I should think, maybe more. Maybe the light shining through it is deceptive. And note the streaks - hard and soft bits. I have more C-grain than straight grain by far, because it's what I use to make all-sheet models. In fact I had only one sheet of 1/16" straight grain remaining to provide the stringers. I value sheets more by the consistency across the width of the sheet than by weight alone. That's not to say I don't value lightness. I've read of this legendary (¿mythical?) "6lb wood" but when I converted that into units I understand,  I realised I've only ever possessed a couple of sheets that might even be in that neck of the woods.

Stephen.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Prosper on December 30, 2017, 12:25:04 PM
A couple of evenings ago I hoiked the skeleton off the jig, and it seemed inclined to maintain its shape so I didn't soak it.

Now I'm plodding along with the remaining work. This fuselage will end up heavy - I keep adding things to it. I've added stringers in the hope of achieving a jug-like fuselage. I've infilled quite a bit of the front too, and there are wide wing saddle pieces - wide in order to provide an anchor for the wing fairings. It may be heavy but it's also a lot stronger than I anticipated. I don't think any cross-bracing of the formers will be needed, though I haven't yet figured out how to mount the wings, and that may involve cross-pieces.

Stephen.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: OZPAF on December 30, 2017, 06:38:32 PM
Neat. Heavy? :) I don't think you will have a problem there Stephen.

Happy New Year.

John


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Prosper on January 02, 2018, 11:47:56 AM
I've been mucking around with ideas for making the razorback, and with other bits, without much result, but anyway here's a bit of progress. . .I've made the engine cowling and roughly shaped the plug for the plunge-moulded nose cowling.

The main piece is a repeat of my F6F cowling: three frames held by four longitudinal members, the whole being planked with softish 0.8mm balsa. The first plank, seen fixed in pic 1. is key - any skew or twist in the bare framework will be set in place when the first plank is attached. Once a few planks were in place but while there was still side access to the longitudinal members, I pared a lot of material off them, and once fully planked I cut the rear formers back a lot too. The item weighs 2.25g which seems a lot. The Hellcat cowl was tissue-covered but the tissue could barely cope with the double-curvature, and this one's at least as curvy, so I'll be finishing it with CA.

Stephen.

 


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: MKelly on January 02, 2018, 01:44:07 PM
That's a great technique Stephen.  Do you find it easier to plank and sand the cowl off the fuselage?  I'm thinking that with your light construction methods there would be a significant risk of breaking stringers and/or formers if one were to try to carve and sand the cowl while attached to the fuselage.

Nice work!

Mike


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Prosper on January 02, 2018, 02:14:59 PM
Quote from: MKelly
I'm thinking that with your light construction methods there would be a significant risk of breaking stringers and/or formers if one were to try to carve and sand the cowl while attached to the fuselage.
No, I don't think so Mike - at least in terms of stringer or former breakage. The CA coating might be a problem if the cowl and fuselage were one piece; that's because the CA coating is so much harder than uncoated balsa that to sand it fair needs a determined briskness, and any slip with the sanding block might lead to a few fus. stringers being suddenly half as thick as they ought to be! No, the separate cowling is in imitation of the F6F which has a separate cowling as per Bill Hannan's intentions IIRC. I found that very convenient regarding the wing mounting. With no firewall forward, the fuselage is wide open close to where the wings join it, so you can work on the wing joint from the inside, so to speak. That's why I'm not particularly worried that I haven't yet worked out how to join the wings. I know I'll have full access to them until the firewall forward is glued on.

Regarding the planking, yes that's surely easier on a free-standing item - see one of the pix where the planks haven't been trimmed off at front or back. That job is a quick trim with a razor and a quick sand with a block. If the planks had to be individually shaped at the back as well as the sides before fixing, that would add to the work considerably. Anyway it's a damn sight easier than infilling between stringers. I've had my fill of infill for now :).



Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: strat-o on January 02, 2018, 02:57:43 PM
I thought this was a neat picture.  It's from a site that is documenting the rebuilding of a P-47 razorback.  http://www.aircorpsaviation.com/project/p-47d-23-razorback/ (http://www.aircorpsaviation.com/project/p-47d-23-razorback/)

It's almost certainly a computer rendering and I think it's an isometric projection judging the way the port wing looks too long.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: OZPAF on January 02, 2018, 06:13:06 PM
That's a very neat practical way to do the cowl Stephen. Identifying the main areas of distortion and working around them seems to be a trade  mark of your work. All your efforts with micro delicate structures  obviously helps :)

John


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: fred on January 03, 2018, 01:28:24 PM
Fascinating build sequence full of interesting techniques.  Thank you
 Was initially wondering How? you were going to line up all those barrel hoops into a fuse ..
 But you managed nicely, albeit  (to My mind :-) in a complex, Seriously taxing for precision method.
 I would have thought a removable central spine/strongback could have worked as well . Mebe not?
 Cowl is interesting as well. 
Merely as idle curiosity: did you consider making a Plug and then vacuforming a Plastic cowl ?
 Results in a few spares 'just in case'


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Prosper on January 04, 2018, 01:46:06 PM
Hi Fred, if you mean making the whole cowling from plastic, I should think that would be incredibly heavy. Even the plastic nose cowling is 1.5g.

I've waded into some treacle today. Yesterday I had time to make the tail surfaces and refine the nose plug; today it seemed that sanding the tail surfaces took as long as making 'em, and after plunge-mould number. . .I've lost count. . .No. 4? 5? I still haven't got a suitable nose cowl. The one atop the cowling in pic 2 is my emergency reserve but I want a better one. The trouble is that the styrene gets a lot thinner at the trailing edge than I'd shaped the plug for. That wouldn't happen with successful vacuum-forming I imagine, but I don't have that facility.

Edit: since writing the above I've churned out a cowling that fits and is very light (0.65g; pic 3) but flimsy. I aim to reinforce it at strategic points using bits cut from the aforementioned failed efforts.

Stephen.

 


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: strat-o on January 04, 2018, 03:10:53 PM
Latest cowl looks great!  Is this plastic purchased for the purpose intended or was it some sort of supermarket packaging find?


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: cast_off_vortex on January 05, 2018, 04:23:32 PM
Quote
Latest cowl looks great!

Took the words right out of my mouth. Mighty fine cowl!


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Prosper on January 06, 2018, 01:49:28 PM
Quote
Quote
Latest cowl looks great!
Took the words right out of my mouth. Mighty fine cowl!
Ta, gen'lmen. There's a bit of progress here, but in the way that more things are nearing completion though nothing's yet complete.

The tail end is close to a finish and the razorback is more or less puzzled out (you can see it radiating out of the 12 o'clock of the fuselage nose in pic. 1: balsa/aliphatic sheet). I've coated the balsa cowling with CA but it still needs a bit more attention; I've made the nosecone (which in this instance refers to the gearbox of the R-2800 engine) and I've reinforced and nearly finished the plastic nose cowling.

The nose cowling is painted because the plastic was covered in a rash of tiny pockmarks - the result of being overheated before plunging. The plastic itself is too thin to have sanded the pockmarks out. I couldn't tolerate the pockmarks but couldn't tolerate the thought of making yet another moulding either. So I slavered the cowl with multiple lashings of paint, and the pits are pretty much filled.

Stephen.

 


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: OZPAF on January 06, 2018, 05:22:14 PM
It's looking very much like a Jug Stephen . How do you think you will handle the nose plug? You make precise work look easy. It depresses me a bit at times :)

John


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Prosper on January 07, 2018, 07:20:44 AM
Quote
Is this plastic purchased f. . .
Sorry, forgot to answer this. It's just regular 40 thou (1mm) styrene sheet AKA plastic card.

Quote
You make precise work look easy.
Ah well that's interesting John. Of course you only see the photos and don't hear me growling and cursing. But seriously, this seems to be a build that I'm prepared to go a few extra yards on. I'm highly confident that the model will fly to some acceptable extent, being a tried design (I'd be surprised if the many changes I've made will impair its stability much - just its duration). That's not true of most of the own-design efforts I turn out. I find it really hard to make that extra effort in finish when the project may well not fly in da foist place, so my models are often slapdash and I often fly them before they're cosmetically finished. If they do fly then I immediately want to make another one, only well-finished: but that plan gets lost in the long "to-do"list. . . This model though could fall at the covering stage. I don't have a clue as to how to cover the fuselage.

Quote
You make precise work look easy.
Well here's a fiddly bit of work. The plan recommends "dead soft" 1/8" balsa, to which I suppose tissue would be attached. I used balsa/aliphatic sheet, and getting the two halves joined at the bottom with a smooth transition round to the trailing edge took some patience. And I still have to affix (as instructions used to say when I was a nipper) tissue to the main part of the rudder without an unsightly border between the tissue and the sheet. That'll be a game. . .

The first side wasn't so bad because I had access to the inside, although trimming the bottom seam to a straight edge was ticklish (pic 2). The second half was harder because there's no access to the inside and the sheet has to be trimmed bit by bit until it meets the first side in a butt-joint. In the end there was a slightly raised edge (4) but this was easily sanded fair.

Incidentally the sheet I used was salvage from a failed 16" span Miles Hawk Major I started a few yrs ago. It pleases me to find that the sheet hasn't degraded over time in any way, so far as I can judge.

All the while I was doing the above I was thinking it would have been quicker, lighter and better-looking to've made the whole rudder from sheet material. That's why probably my forays into S&T models of stressed-skin scale subjects will be occasional only. I reckon the simpler models like the F6F give plenty of bang-for-buck, though, and I must admit I was letting the idea of a hoop-formered L1049G run through my mind last evening.

Stephen.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Prosper on January 08, 2018, 11:17:30 AM
Not much done today - workplace 9°C - too flippin' cold - hands don't work properly.

Normally I'd make a pair of wings concurrently but didn't in this project because I was rather vague about how the wings would meet the fuselage. I had expected to make some kind of one-piece wing or at least, two wings with a strong bridge between them. This would have meant cutting bits out of fuselage formers 4 & 5 and today I veered off that idea for sentimental reasons. Pore ickle laminated formers! Couldn't bear to do it. So the stbd wing has a slanted root rib as per the original design, and I'll somehow have to work one into the (already finished)left wing too. The angled rib very close to the root rib is just to act as an anchor for the wing/fuselage fairings.

Normally a wing made this way will hold together without glue but I used a little diamond file to cut the spar and rib slots, and the slots make a sloppy fit with the 1/32" ribs and spars. This has slowed the work too as things can shift about and there's more checking to be done before gluing starts. In the 3rd and 4th photos here, just the rib/T.E. joints, and the bottom rear spar are CA'd in place.

Also with previous wings made this way I've not used a strip leading edge; the thin sheet wrapped around the nose has made a very good L.E. In this case though I was worried about the sharpness of the Republic S-3 nose, so there's a strip leading edge under the balsa sheathing.

Stephen.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: dohrmc on January 08, 2018, 01:24:13 PM
Nicely done! This is really excellent. I have always wanted to do a Thunderbolt, I doubt I could do as well.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: faif2d on January 08, 2018, 01:52:30 PM
The first model I ever attempted was a WW2 Comet P-47.  This was the one with cardboard formers and pine sticks.  I did manage to get the fuselage built but one of the sets of ribs out toward the tips of the wings was gone, I had traded a cap gun to a neighbor boy for the kit, and I had no idea how to recreate the missing rib.  I did score a WW2 Comet kit about 30 years ago and I guess I need to build it while I still can! I do still remember the dents in my finger from the single edge razor blade that I used to cut out the cardboard parts!!


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Prosper on January 09, 2018, 02:09:06 PM
Hi dohrmc and faif2d. Yes, forcing a single-edge razor to cut cardboard would make an impression on a fingertip. Sort of a 'razorback' impression?

I almost finished the stbd wing today but didn't have time to convert the root of the left wing to the same spec as the right. I fixed ≈ 2° of washout into this (stbd) wing. Varying the wash can be achieved best as the leading edge sheathing is CA'd in place.

My F6F model has 2° washout and no wash on the port wing: this seems to me to give a bit too much right-roll, but I figgered that the Thunderbolt will be less affected by that same 2 degrees because of its elliptical(ish) wingtip as against the broad square tip of the other.

Stephen.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Prosper on January 12, 2018, 12:20:42 PM
I made a canopy plug and produced a test moulding. Apart from being strongly reminiscent of an old electric steam iron, the plug is very big - like everything on the P-47, except the wings unfortunately. I keep thinking I've made the fuselage to 1/24 scale but the wings to 1/26 scale by mistake. . .

Although the canopy moulding is thin it weighs 0.8g; more than I'd bargained for. In fact this model is piling on weight at a rate of knots.

Note the slightly bulging canopy sides - this is intentional.

Stephen.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Prosper on January 15, 2018, 06:11:34 AM
The picture shows the airframe lumped together to get a first idea of weight and balance. It's 4.5g heavier (that's ≈1/3 heavier :o ) than the F6F in the same state, and doesn't yet have its wing/fuselage fairings which will weigh a good bit. The balance is at mid-chord of the wing at the root. The prop will move that forward and the tissue and paint will move it back. I hope it might get by without added noseweight.

Now the wing fairings. I'm calling them that and not 'fillets' because although minimal, they continue unbroken, right around the wing. For the highly-curved parts at the front I'm moulding paper on a small balsa form as shown. To make the long rear panels I thought I'd just drape wet paper over the airframe structure, since there's little double-curvature. However this has proven to be frustrating work. I found a long spring to keep the drying paper in place which has helped a lot but this won't be the quick job I expected. The fairings are necessary not only for appearance's sake but because I find that if the wings are slotted fully into their saddles they have a lot of sweepback. In other words only the front part of the root rib sits in the saddle, and the rear portion is left dangling in space, if the correct 3° sweepback is to be obtained.

Stephen.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Prosper on January 17, 2018, 11:05:44 AM
Quote from: Prosper
I thought I'd just drape wet paper over the airframe structure, since there's little double-curvature. However this has proven to be frustrating work.
I gave up. The sheets of paper draped along the wing/fuselage join didn't dry in a way faithful to the curves they were supposed to follow - they were just vaguely curved wavy sheets of paper. I'll have to retry later.

However I did have success with the front fairing. I decided to try moulding both top and bottom fairings at the same time. The very visible overlap between the two was sanded smooth before sealing the paper. The result, with one coat of paint to show up blemishes, is shown. There are a few blemishes, but these are from the roughness of the balsa mould and not due to any shortcoming in the procedure, so I can live with them.

I'm giving preshrunk and prepainted tissue another try for the flying surfaces. More later.

I've covered half the fuselage. I thought I'd try with a single piece of tissue but had little expectation, given that the Jug has a fat curvy fuselage that looks like a. . .a. . .well, a jug. I
nearly reviewed Bern's Youtube tutorial to give my morale a boost, but remembering the main points (1.Wet a large sheet of tissue. 2. Apply it to the fuselage), I jumped in.

At first it looked highly unlikely that anything could come of it, the folds and wrinkles were so many - but gradually my hopes rose (always a dangerous sign). The tissue was absolutely drenched so I had to keep manipulating it for some long time before it stuck. I finally had to admit that it's worked :o. I took the close-up picture below to ask HPA if tiny puckerings, such as these seen below the top stringer, are a fact of life. After 20 minutes or so I checked the fuselage and even these have gone! Swipe me.

Now, I trust tissue covering about as far as I could throw one or two models I've made in the past, so I'm fully expecting to wake up tomorrow to find the fuselage either C-shaped or exploded, or the tissue split wide open or somesuch, but for now I'm pretty bucked.

Stephen.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: DHnut on January 17, 2018, 01:37:37 PM
Stephen,
              You are providing the usual enlightenment during the build. I have used this technique that was in the Model Builder book on WWII aircraft as used and documented by Doug McHard. I have used it on the Hurricane and the Me 109 in that book. I agree it is a delicate process but works well using dope and thinners as the adhesive. The tension on the tissue does not seem excessive and stress is distributed better over the panel. It is certainly less fiddley than individual panels.
The fairings are always a challenge, for the Hurricane I used a mold as you have done and used layers of tissue and it worked well. The rear fairing was paper rolled around a dowel and was a bit of a pain. I found an art paper for the Magister fairings that when dampened molded nicely and was nuch nicer to handel. It is heavy though.
 Photos to follow.
Ricky


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: OZPAF on January 17, 2018, 05:57:32 PM
Interesting result Stephen. It looks pretty impressive. I would say you have just about mastered tissue covering.
Did you use the dope and thinners approach? I just checked his video and noted Bern actually used glue stick and a hot air dryer!

Would you consider moulding the rear section of the wing fillet similar to what you have done with the front section?

John


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Prosper on January 18, 2018, 12:57:00 PM
Hullo Ricky and John. I must admit I'd missed that Doug McHard tutorial in the book so thanks for pointing it out. The Bern covering video is good for dimwits like me, but is anyway worth a look for entertainment value alone. Although I see the value of dope-and-thinners in some cases (I'm thinking of complex and delicate structures; I was encouraged to try it by George K and Marco and it makes the impossible seem possible. . .), in this case I used my SOP which is a wallpaper-paste type glue applied to the perimeter only. And no hair dryer :). I just kept tweaking and tugging and stroking until things looked tolerably OK. Unlike Ricky's description I found I was using quite a lot of force, or so it seemed to me. Covering the other side will be more difficult I suspect but I have a good excuse for leaving it a while - I want the glue of the initial fixing to be absolutely dry and hard before wetting it again with more glue.

I'm reluctant to make moulds for the rear portions of the fairings because they're so big. I'm just going to see what happens when the wings and fuselage are joined. The advantage of this paper+CA is that it's tough, stable and virtually waterproof. It is heavy though - I got a rough measurement once of 80GSM. In my all-sheet models I use it structurally but in this case it'll just be dead weight.

I managed to cover a wing today with preshrunk and prepainted tissue.

Stephen.



Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: strat-o on January 18, 2018, 01:37:29 PM
Quote
I'm reluctant to make moulds for the rear portions of the fairings because they're so big.

What about carving moulds out of foam?  Foam being cheap and easy to carve.  Then you would have some possibilities along the direction you were going or even try some tissue machet.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: ZK-AUD on January 18, 2018, 01:42:41 PM
Any method Stephen chooses seems to be the right one! but just to add to the discussion this could be an application for Hearty Clay either as an easy method of forming a suitable form,  or even as the part itself, suitably hollowed out once dry


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: DHnut on January 18, 2018, 03:42:51 PM
Stephen,
             There always other options and you have demonstrated another method. It seems that provided the adeshive sets before the shrinking takes place the method will work. It is the ability to capitalise on the stretch in the tissue that matters. I must admit the first time I tried it it was some trepidation that did the Hurricane but it worked a charm.
The rear fairings were not molded but dampened and formed free hand while damp, so hardening with cyano to lock the form would work well.
The wings look good and a testament to you covering ability as I think the silver tissue is a real challenge to get right.   
Ricky


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: OZPAF on January 18, 2018, 11:19:09 PM
Another good covering job there on the wing Stephen. The printed tissue looks neat. Did you print on white tissue or silver?

John


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Prosper on January 19, 2018, 04:16:25 AM
Hi fellers. In principle making these rear fairings with their minimal compound curvature should be easy, and I'll be unhappy if I have to revert to fancy solutions especially as this build is 'over time and over budget' already. I recall that you've mentioned Hearty Clay before Mike, it interests me and I've just seen that it's available in Blighty.

Quote from: Ricky
It is the ability to capitalise on the stretch in the tissue that matters.
Spot on Ricky. When I'm cursing Esaki for its fierce, distorting shrinkage, I should remember that it's the same property that allows it to conform so well to curvy shapes.

Having said that, I can't really curse the tissue on the wing for overshrinking and bending several ribs :(. Seriously, that's what greets me thismorning. They're only very slightly wavy but the air's very humid - might worsen over time. My fault for cutting too much out of the 1/32" ribs.

Just to clarify on the tissue - it's white lightweight Esaki which I've painted. The insignia and stripe were done with brush and stencil and the lines drawn on with pencil with the control gaps emphasised with black pen. The pencil drawing is just a test. The other top wing surface was done first, using a 5B pencil - mistake, it's far too dark and obtrusive! The pictured wing was done with an HB. Consequently, assuming I can cover the other wing successfully the lines will be a lot darker. Oh well, it's an experiment. I think it could be used to good effect with some practice.

I hope to get more done this weekend.

Stephen.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Work In Progress on January 19, 2018, 06:26:07 AM
That fuselage covering job seems impossible, and yet there it is.
Would some kind soul provide a link to this YouTube video?


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Prosper on January 19, 2018, 07:42:26 AM
Hullo WiP try this:

https://www.youtube.com/watch?v=_GYNskBwap0

Stephen.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: OZPAF on January 19, 2018, 07:43:50 AM
Here you go -I need to watch it as well.

https://www.youtube.com/watch?v=DrO-0ktP1qk  part 1
https://www.youtube.com/watch?v=_GYNskBwap0  part 2

John


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Crabby on January 19, 2018, 08:05:09 AM
After I saw that video, that's now the way I cover all my fuses. It's such a relief from laying in bed or driving around town dreaming of all those ^%$#ing tissue bits you are gonna have to fit. Those crazy-canuck-balsa butchers really have figured out the fast way to the flying field!


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: John Webster on January 20, 2018, 04:08:16 AM
Many years ago I watched/handed tools to Ed Fisher (Zippy Sport designer) as he built a pair of fuselage/landing gear leg fairings for a Cassutt racer.

First he taped Saran Wrap to the area where the fairings would be plus a couple of inches at the top and bottom.

Then he applied modelling clay and sculpted it into the fairing shapes.

Then he cut pieces of thin woven fiberglass cloth to size for two layers on each fairing.

Then he soaked the cloth in resin and applied it.

After the cloth set but before it had hardened he used a single edge razor blade to carefully cut through the fairings along the trailing edge of the inside of each gear leg.

After the cloth hardened he wiggled the fairings off of the clay, slid them down the gear legs, spread them at the slit and slipped them off of the gear legs.

Then he removed the clay and Saran Wrap, trimmed the edges of the fairings, slipped them back in place and drilled mounting holes for flat head screws.

Then he took the fairings back off, did some filling and sanding and painted them before re-installing them.

His fairings wound up being about 1/16" (1.5mm) thick but they were on a full size 210 mph airplane.

Around the same time a fiberglass cloth salesman gave me his business card which was made from a hardened resin filled sheet of fiberglass cloth. It was .004" (.1mm) thick.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Prosper on January 21, 2018, 09:31:58 AM
Hi John, that's a nice memory. Stylish craftsmanship.

Covering the other side of the P-47 fuselage didn't go so well; there's a monster patch of wrinkles at the bottom of the fuselage under the wing, and some minor icky bits. Mind you, it went better than I'd dared hope so I'm happy with it. I felt there was no point taking the tissue off. Other attempts would be just as likely worse than better. Anyway, stripping the second half would jeopardise the first. It seemed that the most conservative approach would be to try a patch over the dodgy area, before considering more drastic intervention. This seems to have worked - it's introduced a wrinkle or two of its own, but that's nothing compared to what's underneath.

While measuring the size of the fuselage insignia from a photo I realised that I've got the wing insignia wrong. I thought there was something funny about them. When I made the stencil I was thinking of the earlier version as applied to my F6F model, the style with the red border (much better-looking IMO). I reasoned that since this later style had just two colours and a blue border then it couldn't have blue next to the blue border or it wouldn't be a border, would it? No, so it must have white next to it, so the star must be blue.  Perfect logic.

Oh well, I may try to correct the wing insignia if time allows.

Stephen.





Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Prosper on January 24, 2018, 09:04:46 AM
There's work going on here but no progress, it seems. Messy work trying to remake the U.S.A.A.F insignia - doing the one on the flat surface was okay but the one on the finished wing was touchy. I've also been trying to make waterslide transfers (unsuccessfully so far) and doing some covering jobs - I'm currently waiting for some air with humidity < 95% to see whether the cobbled or reptilian look, which is just visible on the fin and rudder (it's in fact much worse than the photo shows), will disappear.

I had planned a snazzy colour scheme based on transfers (AKA decals) but if I can't make these it'll end up as a bland, generic Razorback but with yellow go-faster stripes.

Stephen.



Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: RalphS on January 24, 2018, 11:32:54 AM
I've also been trying to make waterslide transfers (unsuccessfully so far)

Lots of hard work going on here. 

When you get a few minutes send for a trial pack of decal paper (white/clear/transfer) from Mr Decal Paper off ebay.  This material works for me.  I am using an Epson printer that does not use the waterproof ink - wrong purchase - but after a quick spray with gloss clear acrylic varnish the colours do not run.  Microsol helps to float the decals into position and shrink them down to the surface as they dry.

As a kid we used to find drop tanks in the fens, that supposedly came from 'jugs'.  Lovely big planes.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Prosper on January 24, 2018, 12:35:40 PM
Thanks for the lead Ralph, I've bookmarked the site. I did try commercial paper once before but it was very pricey. This seems reasonably priced. I'll carry my experiments through and buy some of this stuff if they fail.

Yes I suppose the Jug is quite handsome in a way. . .built for comfort not for speed, you might say, although in fact it was very fast once it got steam up, especially 'in the direction of downwards'. Apparently the RAF said that if fired upon, the Thunderbolt pilot could dodge the bullets by scurrying around inside the fuselage.

Stephen.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Prosper on January 26, 2018, 06:18:49 AM
There's now just a wing to cover once the panel lines are drawn on the tissue, but I may cover the fin again as it's wrinkled. The close-up of the fuselage shows where there had been a tiny ruck in the tissue - I think it had snagged on a bit of dried glue on the stringer. Muggins is irritated by this and tries to tease it out. . .turning it from an almost unnoticeable ridge into a major blemish. . .It's fair to say that silver shows up every little flaw, but then so does white, or black, or. . .

For comparison the tailplane including hinges weighs 0.012g/cm2 whereas I would consider 0.016g/cm2 to be an acceptable weight for a balsa/aliphatic sheet tailplane.

Stephen.



Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Prosper on January 26, 2018, 11:02:03 AM
I managed to finish today with something that looks quite reminiscent of a P-47. . .the tails's not 'buttoned up' yet but the razorback is fixed on. This has caused some distortion (as in waviness) of the tissue between the two topmost stringers. The decking is balsa/aliphatic sheet and is so much stiffer than what it's fixed to that it has tried to bend the S&T fuselage to its shape, rather than vice versa. The conjunction of S&T with balsa/aliphatic sheet is something I wanted to investigate and this build has provided the chance. It's worked okay where the rudder tissue is fixed to a sheet part (purple arrow). Maybe I should have fixed the razorback to the fuselage before tissue covering.

While I still had access to the inside of the fuselage I pasted two tiny tissue patches under the blemished area in the previous post, which allowed me to smooth the lumpiness out. After all that faff, it now looks about the same as before I tried to repair it in the first place.

For the first time I have a very close estimate of its final weight. I nearly had a heart attack when I mistook a 10g weight on my balance as a 20g weight, but in fact although - inevitably - a good bit heavier than the F6F, it looks as if it'll weigh about what I expected at the outset.

Stephen.



Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: OZPAF on January 28, 2018, 01:11:12 AM
Pretty good Stephen. You are your own "devils advocate".

I putting my money on a good flying and looking model.

John


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Prosper on February 05, 2018, 10:21:31 AM
Here is where I am with the 'bolt: about nowhere. I had little modelling time last week, and the time I had was used up messing with transfers, using commercial waterslide paper as recommended by Ralph. Pic 1 is my first attempt at application. Can anyone spot that it's a transfer - or does it blend invisibly into the tissue?

I built up layers of acrylic varnish patiently over days to make these transfers. I had found in the past that just a sprayed coat or two was okay for small items but wouldn't hold large transfers together, so I made 'em good and thick, and it seems that they're too strong for the tissue. I thought also that they would carry enough sticky stuff on the back of them to adhere to the tissue when applied (when I made Airfix kits as a boy they would stick okay). Obviously not.

I sprayed the first acrylic coat and then painted the additional layers. Blasting on too much in one go causes the printed devices to split as the arrowed "4" did. I'll try a couple more with glue underneath to fix them - if that don't work it'll be "Plain Jane" rather than "Hun Hunter".

Stephen.



Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: RalphS on February 05, 2018, 03:54:19 PM
Possibly too much varnish.

Looking at Mr Decal Paper's instructions he says that too much varnish can harden the decal making it difficult to apply.

I only give the decal sheet two thin coats of Humbrol Clear Varnish (rattle cans).  I was introduced to "hot-spray" system paints
in industry and when using spray cans I always put the can in a jug of very hot water for a few minutes.  This thins the paint
and increases the pressure giving a fine coat.

I read, in a plastic model magazine, about the use of Microsol to float the decal into the correct position and flatten the decal as it dries out overnight.  This works well and I don't bother to over-spray the decal once in position.

In my pics, all lettering and insignia are decals.  Some are painted first as a sheet then cut out, some are inkjet printed on clear decal paper, the insignia are inkjet printed then cut out. 

As I was told, as an apprentice, "don't give up while there is material in the stores".  ;D
 



Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Prosper on February 05, 2018, 05:02:32 PM
Ralph, those beautiful models. . .geez. That Hawker Fury is a major lovely. That was the scheme I was going for on a Hawker Fury I started several years ago and failed to finish because I couldn't cover the wings. It's good to see how it should have looked!

I didn't miss your mention of Microsol in your earlier post, but thought that it might not work with, or might attack even, the silver paint I've used. I hate to buy something and find that it doesn't work and that there's no other earthly use for it.

Yes I think the transfers are too thick and crispy. Perhaps the bigger ones willl work with some fixative underneath them. I agree completely with the 'material in the stores' thing and generally live by it - but the material I find lacking presently is time! [discussion: is time a material?]

Regards,
Stephen.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: OZPAF on February 05, 2018, 05:07:41 PM
You'll get there Stephen. A minor setback for someone with your detailing talent. :)

John


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: billdennis747 on February 05, 2018, 05:32:12 PM
Stephen, I echo what Ralph has said. I give just one coat - enough to stop the ink running. I recently used Humbrol Decal Fix which seems to do the same as Microsol. They claim it lets you apply the decal to a matt surface.
I do, however, give a sealing coat, otherwise I find bits chip off eventually
Bill


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Pete Fardell on February 05, 2018, 06:27:48 PM
Ralph, those beautiful models. . .geez.
I was just thinking exactly the same when I saw those three pics. I mean, we already knew each model was a little gem, but when you see them all lined up in a nice row like that... well, sheer class and somehow (like all the best modellers) with an indefinable unifying style.
(I won't go on though. Don't want to embarrass the poor chap!)

When it comes to producing decals, I'm quite good at producing two kinds: the run-when-wet sort and the thick-hard-need-nailing-down sort. The in-between kind, not so much.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Prosper on February 06, 2018, 03:47:06 AM
Thanks all, for the advice and encouragement. My printer is u/s at the mo, but I can take another shot when it's running again. Meanwhile I'll see what I can do with the rest of the sheet I've produced. And anyway there are many other jobs to do on the model - I just wanted the transfers on before assembling the airframe - much easier to work on single components rather than the whole doodad. I'd knock the tail off while concentrating on the nose, or something.

I'm no footie fan by any stretch, but don't they also have trouble getting their transfers done before the season closes?

Stephen.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: OZPAF on February 06, 2018, 04:46:51 AM
Too much fixative? :)

John


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Prosper on February 13, 2018, 09:12:44 AM
Update - or perhaps downdate would be more accurate. This project has been overtaken by work, meaning I only have odd bits of time to spare at present. What's more with the possibility of Spring appearing in a couple of months my priorities have changed. I'm using most available time to prepare balsa/aliphatic skin panels for models that will need long grass for trimming flights. Cutting a panel then wetting it and binding it to a mould takes a few minutes and little thought: the panel's then left 8 or 10hrs to dry, released, and another one bound when a few minutes are available.

However I had a go at covering the right wing of the P-47 this morning. I shouldn't have tried with fingers stinging and part numb with cold, nor with a forefinger out of action through injury. But without those handicaps I'd probably have messed the task up anyway - that's my way with tissue covering.

I seem to remember covering the left wing with dry tissue that was good and flat. Because the prepainted tissue panels for the right wing had been lying around for weeks they had taken on a cobbled texture, and I had to wet them thoroughly so that they would shrink taut and flat. When applied, the bottom panel slithered around and then grabbed very unevenly, introducing a great bow to the trailing edge once dry. I had to tug the top covering as hard as possible to eliminate this bow, and when the dust settled I saw that the taut top covering had slackened the bottom covering; that the bow was still there and that the cobbles were still visible on both sides.

Oh yes - I also wrecked the covering of the fin a few days ago by attempting to glue the curly transfer (previous post) into place. this worked but the springy slab of transfer plus the glue were much more solid than the tissue once dry, the result being wrinkled tissue around the transfer.

No steps forward, two steps back is no good for me at the moment. I'm setting the Thunderbolt aside until I can take a clear run at it to get it back on track.

Stephen.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: strat-o on February 13, 2018, 02:18:29 PM
Quote
No steps forward, two steps back is no good for me at the moment. I'm setting the Thunderbolt aside until I can take a clear run at it to get it back on track.

Still, it's cool to see this.  Doesn't tissue covering tend to taughten over time?  If you set it aside for a time, it may resolve itself.  Nice seeing the details like the shell ejector chutes on the underside of the wing.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: OZPAF on February 13, 2018, 10:46:13 PM
Hey it doesn't look that bad Stephen. I'm wondering how 3 - 5 thou mylar would work on these light structures?

That's a funny dance you're describing.It would leave your partner in limbo!

John


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Prosper on February 14, 2018, 06:24:54 AM
Hi Marlin and John. I think if the tissue shrank some more it might efface a few of the wrinkly bits - but would warp the wing more too. The bowed t.e. I mentioned means that there's maximum washout where the yellow stripe is, then it decreases toward the wingtip. I think this preshrunk and prepainted tissue may have no more 'shrinkability' anyway, other than any I lent it by tugging it taut during application.

I expect Mylar would work for one knowing how to use it. I tried Mylar some years ago and realised it was a technique in its own right, not just a variant of tissue covering. Another thing to be learned and mastered, with the time and effort that implies. . .it doesn't hold enough interest for me to get that involved.

Quote
It would leave your partner in limbo!
that's where the "clear run at it" comes in John! Lots of steps back then a run to catch up - it's called the "Merry Dance". The partner, name of Esaki Tishoo in this case, stands there looking relaxed and smug, while I scurry round agitatedly :).

I'll get back to this model later this year I expect.

Stephen.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Prosper on December 13, 2018, 05:47:45 AM
Quote from: Me, last Christmas
Hi gang. Ho! ho! ho!

Hi gang. Bahhh, humbug.
My Leopard Moth has been temporarily shoved aside to finish (cough) last yr's (cough) Christmas project. My reasoning is that if I can finish it, it will look so gaudy, tinselly and colourful that there'll be no need to put up any other decorations.

I left off (see reply #70) because of tissue covering problems. One wing had a bowed trailing edge and the other had more twist than a propeller blade. The fin was all pebbledashed and pockmarked. The twisted wing was the straw that broke the camel's back - the thought of trying yet again was too much - but a year later, trying again seemed like a piece of nothing, so a few days back I made some new wing coverings, pre-painted on glass. Then I stripped the old coverings off and noticed that after a short time the twist and the wavy ribs of the balsa structure re-straightened of its own accord. So it wasn't that the wing structure was too weak but that the tissue was pulling too hard (I think). Nevertheless I beefed both wings up a bit with gussets and stiffening strips on the inner ribs.

I was very nervous about covering. I cut each tissue cover from the glass at the last moment (to keep it flat) and kept it dry. I used my usual wallpaper-paste-type adhesive. The first wing - first the bottom then the top - went okay, a few wrinkles but I still felt relieved. The second wing, yesterday morning, didn't work so well. The dry tissue and undiluted paste gave very little working time and when I applied the top cover the tissue had stuck firmly at the wingtip while I was still intensively smoothing the inboard edges, so I had to work the tissue to tearing-point to try to get it smoothly round the wingtip. The result was more wrinkled than great-aunt Ermintrude, and even in a warm and very dry part of the house it didn't un-wrinkle that much.

However, thismorning, Lo! the tissue is reasonably smooth and the trailing edges are - well, not ruler-straight, but not too offensive to the eye. I'm hoping things will stay that way. The only thing is that if there is wing twist discernible I think it's the wrong way, as in some washout on the left wing and maybe some washin on the right. I may have to accept a model that circles the opposite way than I'm used to. . .

Also yesterday I re-tried the waterslide transfers I printed last yr. These were a stumbling-block too. The test one I tried last year curled up and effectively destroyed the fin covering on one side. This time I've managed to get the design "40" on the fuselage side. I applied a thin brushing of wallpaper paste before sliding each numeral into place, and the transfers have dried overnight without curling up () so far. I was disappointed at how transparent the printed blue is - the result is a darkish metallic blue not a bright light blue, but hey-ho, live and learn etc.

So, at the moment it's looking like I've got all the doings of some kind of flying machine. I'm going to stick it all together however wrinkly, curly-transfered or twisty it gets. It's supposed to be a Funderbolt, for Christmas, really.

The pictures show first how it all looks as of thismorning, then a sequence showing the painting on glass. All the painting is brush-painting, and I took special notice of Richard rudder flutter's point that the side bars of the U.S.A.A.F. star are not central but raised a bit. To mark panel lines I made a paper template of each wing surface, with the panel lines marked in black. Then I lifted the sticky tape at the edge of the glass and slid a template under the painted tissue. The black lines just showed through the silver paint as a guide, so I could draw the panel lines on the paint with ruler and pencil. They're not very visible in pictures but look quite effective. I used an HB pencil; a softer pencil (but not so soft as 5B - I tried it) might be better.

Stephen.



Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: charlieman on December 13, 2018, 12:47:54 PM
How did this gem of a thread miss me for near a whole year??!!
OUTSTANDING as per your usual.
I particularly liked  observations about airfoil progression as exhibited on full size P-47. Even AT-6 and P-40 wings, with ostensibly"simple" straight tapered planforms don't have have airfoil sections progeessing from root to tip in obvious linear fashion. Both  have near identical split fap arraingment as Spitfire's outer panels. All three compromised thier theoretical airfoil progressionto accomodate flap and ailerons. Spit's airfoil progression less compromised l on top surface, although overall all more complex(more faceted sectios). T-6/P-40 also compromised their upper surfaceairfoils with spar/skin attachment whichis straight intermediat line, which also cross"normal" percntage progession line. Both appear to me to use normal progress ion to section/rib at end of a flap, then describes a different line of progression for aileron. So, I'm surmising only root ,flap aileron section, and tip uses normal progression. Everything between those sections would be compromised. P-51 wing does that a couple more times!

charlieman aka packardpursuit



Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Prosper on December 13, 2018, 02:27:20 PM
Thanks Packard, it's always good to hear from you and learn from your deep-down knowledge. The older I get the more I want to know about the technical aspects of aviation design and history. The P-51 wing was a strange one all right. Very fat at the root (17.5% IIRC) just as other companies were busting a gut to make thinner wings. Oddly enough, rather than using huge technical input chasing laminar flow (they prob'ly couldn't afford to) Martin Baker used the RAF 34 section on their MB-5. The RAF 34 was ancient and was used on such things as the  ABC Robin ultralight of 1929 - a kind of giant model aeroplane. It just happened to have some of the features (the section, not the Robin!) of laminar flow foils developed a decade later. De Hav liked the RAF 34 too.

I'm rushing this model at the moment, and of course quality and accuracy suffer. Today I started on some cockpit detail - this will be sparse, but I suppose it needs a panel of sorts, armoured glass, a gunsight. . . I made the exhaust outlet from mashed paper and made the cooling gills at the back of the engine cowling, so now I can try to apply the transfers either side of the cowling, which carry on to the gills. I did the last stencilled insignia but not the filling-in of the blank bits. I covered and painted the fin for the 5,087th time, and slapped red paint on the nose cowling. This is erring to the scarlet to be closer to the muddy orange-red of my "Hun Hunter" transfers. A day or two back I painted red onto the silver base of the cowling, only to find that the red paint is so transparent that it would take 5,087 [h'mmmm - coincidence?] coats to cover the silver. So today I had first to repaint the cowling white as a base coat, and it will take a few more red coats to look at all even.

Incidentally the colour and markings info come from the William Wyler propaganda short "Thunderbolt". I haven't watched it for a year or more but I think the featured squadron were on Corsica, carrying out ground-attack. The cameras must have been there a while because the aircraft started with yellow stripes and later sported black lining to these stripes. The colour of the print I D/Ld from youtube is washed out and it's hard to see - or guess - what shade of red the 'planes used.

Stephen.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: vtdiy on December 13, 2018, 04:07:32 PM
This is a truly fantastic thread. I love the part also where you paint and detail the tissue off the plane and using a brush and stencils. Great stuff, and a beautiful plane and workmanship!


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Prosper on December 14, 2018, 12:24:36 PM
Thanks vtdiy. The prestretched and prepainted tissue thing seems to me good for covering where there's little or no double-curvature. As I've just reminded myself, being able to paint - either freehand or with stencils and masks, and either brush or airbrush - is much easier on a flat surface with a firm backing. The end product is different though - it's less likely to wrinkle and is tougher, by dint of the paint. But by the same token it's less keen to conform to compound curves. I've yet to discover what its limits are regarding curvature, but I'll probably just use it for covering simple shapes.

Today I got some more done at the front. The nose is really a copy of the F6F Hellcat model I made - a printed 'engine' and some very crude detailing just to give the impression of depth. Tommora's forecast to be wet, cold and windy so maybe I'll get further on and snap a few photos to post.

Stephen.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Prosper on December 15, 2018, 01:23:09 PM
Well I was steaming along nicely this a.m. despite the cold, and I thought I'd get the cockpit area done as well as the nose firewall forward - that was until I looked for a brass thrust-bush to carry the propshaft. I have a little collection of such items 'pre-owned' as in from defunct models, but none to fit this model. A new one involves making 1mm I.D. brass tube into 1.2mm I.D. tube 6mm long. Why this horrid exercise should take over an hour and great anguish is too convoluted to tell here but involved a 1.2mm drill nearly new but completely blunt; a finished bush dropped and lost (maybe under the skirting board?); brass tube bent so that even a 6mm length would be suspect for straightness; red hot brass (no not the colliery band playing the local town hall) and the bush seen in the photo wasn't separated from the parent tube by a saw but was sheared off in rotation. I don't know when I'll see the funny side of this - 2025?

The gearbox housing, or whatever the correct name is, could do with another coat of grey and some gloss varnish. The waterslide transfers went on easily tho' perhaps I should wait to see that they don't curl at the edges before sounding too pleased. It now seems to me that they're much too thick - this after experiences a year or so back of homemade transfers disintegrating before they could be positioned. When the thick edges of these transfers catch the light they look pretty ropey. And there's the business of a white undercoat to be addressed. I'm not sure what this squadron emblem represents - is it an oozlum bird?

I want to do a bit more finishing work on the fuselage before fixing the wings, and when the wings are in place the nose section can be fixed too.
 
Stephen.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: tom arnold on December 15, 2018, 03:10:28 PM
Stephen, I have a couple of questions on this fine build. The first is: what do you use for your masks for the insignia and what do you use to stick them down on the painted tissue? Do you have "bleed under" of the masks using a brush (which is much juicier than air brushing)? The other has to do with the cowl opening. I can imagine the fabrication of the crankcase but can you run over the sequence of events to install the air duct mouth below the engine?
Many thanks in advance. This is a beautiful job on one of my favorite airplanes and you have taken on SILVER in addition. Brave men, you Brits.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Prosper on December 16, 2018, 05:07:52 AM
Hi Tom, thanks for the interest. The star-and-bar stencils were cut out of paper. This is where the advantage of painting on glass shows: because you've got a firm base to work on you can use all the fingers and thumbs you can muster from one hand, to keep the stencil in place, and have the other hand for the paintbrush. With the stencil flat on the tissue there was very little bleed-under and what there was I think I could have avoided with a bit more care and patience. Now, the stencil for the rear fuselage insignia shows the difference. Keeping this in place with Mk.1 fingers was near impossible, and getting the edges snugly on the surface of the double-curved fuselage was impossible. The left-side job was a mess. The stencil had very wide borders to stop overspray. Then a cog went round in my head and I realised there was no need for these borders when brush-painting. Duuu-h. So I cut the borders right back which allowed the stencil to fit to the fuselage much better, and used two thin strips of 'Yellow Frog tape' to keep it put. That gave me a few free fingers to press the stencil edges down where the brush was working at any moment. The right-side insignia came out better! However this was on a surface replete with stringers and pretty tough. Doing the same on a wing with just a few ribs. . .unsupported sagging tissue. . .hmmm. I used a square-ended brush. The particular mix of black, white and blue inks dries very quickly which helps a lot, and I try to think of the stencil edges as a guide rather than as a safe protection against bleed-under. Which means I paint around the stencil bit-by-bit - definitely no sweeping a paint-loaded brush across the whole stencil. The gaps left by the stencil were filled in freehand. I might touch-up the arrowed flaws in the pic - or I might not. In the past I've been stuck in a neverending loop of touching out the flaw with the other colour/making a bloop/painting out the bloop with the first colour/making another bloop/painting out the bloop with the other colour/wondering where the day's gone/

For simple straight lines as in the yellow stripes I used Frog tape on the tissue but it has to be peeled off vaiiry slowly and gently or it'll rip the tissue. I think for another build I'd use an airbrush, and try harder. With an all-sheet model Yellow Frog tape can be stuck directly to the surface, but it still needs great caution when peeling off.

The air duct mouth is just trickery. It's just a bit of a failed plunge-moulding with the correct radius - probably from this build or perhaps my very similar F6F model. Glued on to the front former of the fuselage. The walls separating the different intakes are balsa/aliphatic sheet folded in two to give a smooth face on both sides. TBH this is all very sketchy and based on a couple of distant pictures. The real insides of the P-47 cowl might be completely different.

Stephen.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: vtdiy on December 16, 2018, 10:33:01 PM
Thanks, Prosper for explaining that. I was wondering myself how you could paint with a brush and paper stencils. It's not magic after all, just skill and finger dexterity! Well, and fast drying ink -- (I was thinking paint). I would like to try it some day, and I guess if I was doing it off of a plane and on glass, it could just be a kind of practice and not actually running the risk of ruining anything.

It must be very satisfying to know you did all that, as well as it looks, using just hand skills.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: tom arnold on December 17, 2018, 02:10:17 PM
Thank you, Stephen. I think you are more of an artist than you give yourself credit for.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Prosper on December 20, 2018, 04:20:31 PM
. . .I guess if I was doing it off of a plane and on glass, it could just be a kind of practice and not actually running the risk of ruining anything.
Exactly. It occurs to me that perhaps someone has asked themself, why doesn't the paint stick the tissue to the glass? Well it can do, and I'm still getting a line on this: if you put on lots of paint it bleeds through the tissue immediately and ought to cause the tissue to stick hard - except that the tissue wrinkles up and naturally separates itself from the glass, and the process of drying and shrinking flat is one of movement, which prevents sticking. If you  brush on paint sparingly and slowly it will dry before it's penetrated the tissue and so form a barrier to subsequent brushings.* I think both these statements are true, but tissue does stick to the glass to some extent either way. It can be peeled off easily, or in this case I made a 'spatula' from paper and pushed it between the tissue and glass, and it separated any stuck bits easily. Next time I try this method I will put a sheet of adhesive-backed plastic film on the glass as this is very non-stick and may avoid any sticking at all.

I got two or three hours in today, enough to do the armoured glass and reflector sight c/w leather crash-pad. The reflector sight had a ring-sight next to it but that's just too much to attempt for me. I may add the post with the bead on it, ahead of the windshield, if I remember. Maybe I'd have done the canopy framing today too but got sidetracked into attempting a pilot bust. I measured a few dimensions and sketched them on my cutting pad, and I swear he looked like the All-American hero, but after 20 minutes chipping balsa the result looks more like Lefty McGoohan of the Islington mob.** Still, mustn't judge a book by its cover, eh?

Stephen. * I'm talking about acrylic paint here. **I just heard Lefty's not pleased with the likeness and he's put out a contract on me. :o



Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Prosper on December 21, 2018, 02:48:42 PM
I decided I couldn't bear having so evil looking a pilot figure in my (scratch built ;D) model Thunderbolt so went to work on Lefty and came out with a more likely lad. He seems to be sticking his neck out a bit - I might do something about that. He weighs 0.2g - bless. I got a start on the canopy framing (painted sticky tape) before laying off. I'm not looking forward to getting the thin strips into position.

Stephen.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Crabby on December 21, 2018, 03:24:00 PM
Cut his head off and turn it 30 degrees. He's looking for a scrap!


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Mefot on December 21, 2018, 06:11:00 PM
I wouldn't in a million years question your building accuracy or skills but I think I am right in questioning your rendition of the pilot. No P47 pilot worth his salt would embark on a sortie without flying helmet,goggles and an oxygen mask. Personally I would start again and carve another pilot that was more historically accurate. I am thoroughly enjoying this build and only wish I had half the ability and skill you demonstrate in your builds. Put simply, a pair of goggles, mask and helmet should be simple to carve. Don't throw your current rendition away though. I could think of a thousand prototypes he would suit !!!  ;D ;D ;D ;D


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: cast_off_vortex on December 22, 2018, 04:59:08 AM
Having built the Comet P-47D three times, each time a little better than the previous build, I have to say you have perfected the egg shaped cowl. I never could get it symmetrical  :-[. Excellent work on the cowl flaps as well.

Just an all around fantastic effort. I am really itching to see this put together.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Prosper on December 22, 2018, 02:04:47 PM
Quote from: Crabby
Cut his head off and turn it 30 degrees. He's looking for a scrap!
No sooner said than done! He's definitely looking for something. . .I think it's Italian girls.

Mefot you're right, but I must admit I considered that doing the mask/goggles thing would be harder than shaping a rudimentary fizzog. Maybe next time. . .I still keep changing my mind as to the need or suitability of pilot figures in the first place.

Thanks COV, I appreciate it. Now the canopy's in place I should be able to assemble the model in the coming days.

The sticky-tape canopy framing was a faff to be sure, and the result isn't great by any means. I'll be adding more paint here and there and I see from the photo I forgot the join-line between hood and windscreen. And the rear-view mirror. Never mind - all this cockpit stuff (as the whole build really) is 'impressionistic' - as in based on what I remember from a photo I looked at the day before - rather than exactingly measured, prepared, checked and built.

Stephen.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: charlieman on December 22, 2018, 02:31:16 PM
cast off,

I noted a HUGE improvement in my personal skills when I started to embrace some advise I got from a professional model maker. His mantra was: Build in, or use "controls", at every opportunity. A mechanical cut is better(for accuracy) than a freehand cut. Which is also why a sanding block is to be preferred over sand paper, held in the hand. It's a mind set, actually. As you look for opportunities, new applications and situations will become more  apparent. Start simple. Fuselage symmetry is enhanced when 1/2 formers are cut-out and finalized together (held together with rubber cement) . When separated and 'un-folded" you have identical Rt/LT formers.  When carving block materials, precision shaping is less troublesome if the block is cut on a mitersaw , providing an exacting placement for paper or even  ply (and symmetrical!) patterns can be introduced into the re-glued block. Having a positive former IN the block is, in my opinion preferred to using a negative cutout, at guesstimated section placement, over the block. One pretty much tells you exactly when to  stop removing material. The other is constant guess, check, guess again, re-check....etc.  Contrasting colors of the pattern against the block is an additional form of control.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: John Webster on December 22, 2018, 09:52:11 PM
Smooth the edges of the armor glass panel and apply a coat of transparent green paint to them.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: vtdiy on December 22, 2018, 11:19:59 PM
Prosper, I like your pilot just the way he is. Gives it character, and I'm sure someone somewhere in history must have taken a P47 up one flight naked faced, and looked out the cockpit sideways, too!

Me, I never did put pilots in my planes, but after a bunch of people started asking for one when I built my Morane Saulnier, I broke down and did it. Not having made one before, the first thing I had to figure out was how big to block out the little foam guy (or gal).  I mean how big a head, shoulders, how thick body, how tall from seat, etc, etc.

Sitting down with a measuring tape and paper and pencil I measured my head and upper body while seated -- wrote those figures down. Then I figured out the scale by comparing the full size wing with the wing I'd built. Then I used that scale factor to multiply each of the pilot feature sizes.

Blecchhh! That's the hard way. Repetitive arithmetic. Time for a simple tiny spreadsheet, and I figured I could use it for different models at different scales in the future. It worked. You just enter the full sized plane's wingspan, and your model's wingspan, and it scales the pilot's dimensions.

If you're interested I can post it, though I guess that would also take permission and assistance form a forum administrator.

Anyway, your man is beyond the birthing stage, and seems quite happy in his jug!


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: charlieman on December 23, 2018, 12:13:57 AM
Or, one can go on line and see if here's any handy info available to art and ergonomic students, seeking proper human proportions??? Once you know the scale of your model and you decide how tall you want your particualr pilot figure, scale ruler, even if it's just a quick pencil sketch with hand drawn increments,  makes the math non-existent.

 I tried measuring my own body for a full scale seating arrangement, once. Seems I couldn't  fit my HUGE melon inside the aircraft! ;D


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Jack Plane on December 23, 2018, 03:35:55 AM

I noted a HUGE improvement in my personal skills when I started to embrace some advise I got from a professional model maker. His mantra was: Build in, or use "controls", at every opportunity. A mechanical cut is better(for accuracy) than a freehand cut. Which is also why a sanding block is to be preferred over sand paper, held in the hand. It's a mind set, actually. As you look for opportunities, new applications and situations will become more  apparent.  [...]


Charlieman, I don't disagree with your view, but to add to it:

The late David Pye, professor of furniture at the Royal College of Art in the 60s and 70s (and architect, boat-builder, industrial-designer, turner and wood-carver), analysed the difference between Workmanship of Risk and that of Certainty in his book
 The Nature and Art of Workmanship (https://www.amazon.co.uk/Nature-Art-Workmanship-David-Pye/dp/0713689315):

‘ … simply any kind of technique or apparatus, in which the quality of the result is not predetermined, but depends on judgment, dexterity and care which the maker exercises as he works. The essential idea is that the quality of the result is continually at risk during the process of making; and so I shall call this kind of workmanship “The workmanship of risk”.’

Risk gives rise in the finished object to diversity which he believed valuable, and which I agree with.  Increasing the degree of certainty or regulation in making (e.g. templates, jigs, fences, stops, etc) increases making speed and reliability, and so becomes economically-efficient, but - in my view - at some aesthetic cost to the object and a philosophical one to the maker.

It is difficult to sometimes put into words the difference between - at either extreme - the 'quality' of a properly hand-made object and a production-manufactured version of identical design.  But I believe that - like the difference between an original painting and a high-quality print of it - the hand-made object, even one made to the highest levels of precision, carries in it a trace or aura of the human.  A sensitive observer will feel this immediately.

There is always satisfaction in working out 'regulated' solutions for repeat operations to save time, money and tedium (one reason why I've got large machines to make initial processing of materials radically more efficient) but, especially where it comes to our hobby, there is also the 'meditative' quality of passing time, hour by hour, week by week, as each part of the model comes together.

PS: Stephen, I hope you don't take this as a 'high-jack' of the thread:  your work, like that of many others, exemplifies to a very high degree what is possible with working by hand and at risk.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Prosper on December 23, 2018, 05:14:08 AM
Absolutely not Jack Plane, that's really interesting and I intend to explore further when time allows. In fact I've always thought that time is the risk element. If someone took a lifetime to build one scale model, I expect it would be a very good scale model. As soon as time comes in one's taking chances with quality and fidelity. Broadly I prefer scale models where there is (ideally) absolutely no evidence of the builder whatsoever. In other words, all Spitfire and no Prosper. This is impossible to achieve in practice but does tend hard towards charlieman's  "control" viewpoint. This model by contrast is more of a 'freehand' or 'freewheeling' effort, however I'd still rather have a model that shows the P-47 and not my creative skills and lack thereof. I know there's a strong following for models that clearly bear the signature of their designer or maker, or clearly  signal the builder's high art and mastery, but that sits a little ill where scale models are concerned IMO. I'd rather efface myself from the business, the better to show a layperson what a 1930s Leopard Moth (for instance!) was actually like.

You're right John, I think the armored glass frame is primer green - or at least not bare metal as I was imitating (see pic). That's what comes of working from memory. With my 'more serious' builds I pay much more attention to these kind of details (where the evidence is available to me, that is). Anyway it's too late now the canopy's glued down.

I've just made the gun shrouds.  I was going to plug the rolled paper shrouds through the leading edge - I put a backing plate behind the L.E. in anticipation of this - but these were so easy to make that I think I'll treat them as semi-disposable and glue 'em straight onto the wings. That saves weakening the L.E. and saves time. If one gets knocked off or lost I'll only be semi-annoyed.

I'm happy to work from measurements vtdiy but thanks for the offer. This fellow is 1/24 scale and I wanted not to oversize him, in order to emphasise the bigness of the P-47 by contrast. Yes, I imagined him doing a quick airtest after they'd fiddled with the mags or changed the plugs or something. That means what he's really looking at is the airfield, in case the engine conks.

Stephen.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Crabby on December 23, 2018, 09:16:24 AM
Guys who make pilots for the first time usually put the eyes too high. Also, hair has sculpted elevation as well as other features. Stephen, in my unsolicited opinion your guy looks very competent. Relaxed to be sitting in a powerful contraption of stick and tissue!


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Prosper on December 26, 2018, 10:44:03 AM
Wing fillets. . .aaaarghhh. . .I almost wrecked the whole model - as in having to re-cover the fuselage and one wing, which would probably have led to me putting the project firmly back on the shelf.

When I made the fuselage and wings in the first place I made sure that where the fairings would attach there was balsa structure, not just tissue. But I didn't make sure that the tissue was firmly stuck down to the structure in all the relevant areas, so in places I have been sticking fairing panels to tissue paper which is just sitting on the balsa backing and not fixed to it. I started off using aliphatic glue (the rubbery kind) to give me some working time and time to reposition. In fact the bending forces needed on the panels was such that even holding the panel in place with fingers and thumbs while humming a few carols didn't work; the panel would smugly peel itself free a minute after I stopped clamping it. Then I found after gluing that I had cut one of the nose pieces wrongly and it didn't fit (this time the aliphatic gripped strongly and  I nearly started ripping tissue when working it free). Dry-runs don't always reveal the truth. I finally resorted to using CA. I'm more comfortable with this generally but it's a one-shot approach - if you make a blunder using CA then, if you'll excuse a pun (it's Christmas after all) - then it's cyano-ara, baby.

I've got one side done bar the yelling, and I'm making a new nose-piece for the other side. The whole biz has my nerves twanging. The nearly-finished side is not much short of a mess (see the discontinuity in the front/rear join). The tissue is wrinkled in places and I just hope it smooths out when the RH drops - it's near 100% just now. Stick and tissue + fillets is for braver people than me.

The wing fairing components weighed 0.85g, this is reduced by trimming to fit but increased by glue and the fairing wedge at the back.

I fixed the wings on before Christmas. Scale dihedral is 4° on the top surface of each wing (from Republic). That means ≈ 5.4° along the leading edge, which is not a very generous amount. My instinct is that it'll do. Hullo who's calling, ah, the Famous Last Words Dept. Wonder what they want?

The other photo is to show a pleasing aspect of pre-painted tissue - it seems to have very little sag. I photo'd the bottom wing surface because it has more curvature than the top, except right at the front.

I added a few more transfers and made underwing pylons from mashed paper.

Stephen.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Prosper on December 28, 2018, 05:31:08 AM
Well, 'tis nearly done now. A bit more work at the tail and the wing fillets is needed, and I hope to make a prop tomorrow a.m., after which it needs the rest of the transfers applied and another round of detailing - various turbocharger ducts, aerial mast and what have you.

On the scales it weighs 26 grams. In addition to this, 4g of lead on the nose balances the model at about 1/3 root chord. I expect a four-blade prop to come in around 4g but I shouldn't be surprised if it will require more noseweight even with the prop, because probably the CG will need to be forward of 1/3 chord. It's going to be much heavier than the F6F Hellcat at the same 1/24 scale, and IIRC it has significantly less wing area. However, that's the outcome I expected - and wanted, in fact: I want something that won't fly away.

As for flying, I still have no field to fly on. My neighbour seeded 'my' flying field with grass so late in the year that now there's just a tint of green from a zillion tiny grass blades and it's far too fragile to walk on, never mind the mud. Looks like it'll be Spring before I can do anything but test glides and powered hops.

Stephen.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: DHnut on December 28, 2018, 06:24:08 AM
Stephen,
             The build is up to your usual standards. I linke the way you use the paper to give the panel lines as the discontinuities at the edges are much more realistic than lined panels.
The weight looks fine as the real aeroplane was no floater and should not waft around like a Cub or Leopard Moth. The Me109 at the same scale weighs in at about 25 gms and has a lot less wing area so I am not expecting a slow flying model.
Like you I am waiting for a weather window to trim in, but without the restriction on the flying fields availability.
Ricky


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: vtdiy on December 28, 2018, 09:25:46 AM
It's looking really good!


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: LASTWOODSMAN on December 28, 2018, 09:46:32 AM
Very impressive Stephen!

LASTWOODSMAN
Richard


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: tom arnold on December 28, 2018, 12:52:21 PM
I don't think you better plan on a short flying, heavyweight as your weights are very good for a flying model. At 1/24 scale, that is a 20.37" span and 75 sq.inch wing area. That gives an empty wing loading of .4 grams/sq.inch which is very good. If you put in 30% of the model weight in rubber, the wing loading only goes up to about .5 grams/sq.inch. I realize that you UK types are not hung up on the time fetish of the US lads but that model would be ferocious in an FAC mass launch.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Don McLellan on December 28, 2018, 03:49:06 PM
This is beautiful work considering it is a silver model.  Very well done Stephen!


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Work In Progress on December 29, 2018, 04:18:40 AM
It's absolutely every inch a P-47D. I have the same aircraft as a static model in 1/48 and that doesn't look any more realistic than yours. Well done indeed.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Dan Snow on December 29, 2018, 07:17:05 AM
Watching your progress on this bird I realize I'm watching an expert at work!  I only wish I had 1/10 of your expertise and talent!! 

Fantastic job!!


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Prosper on December 29, 2018, 02:59:12 PM
Too kind fellows, but I do appreciate the comments anyway. Those caveats 1)the camera flatters and 2)it hasn't flown yet - still apply!

Once again I see, with another model (nearly) finished, that a collection of blunders, bodges, makeshifts, gloss-overs and close shaves can be assembled into an object that is rather handsome, seen from a bit of a distance. 'The Whole is Greater than the Sum of its Parts'. I think yer real Maestro can probably make such an object from beginning to end without a flaw - or maybe just one flaw to prove that they're human :).

I made the 7" propeller and the freewheel so the model just needs a motor peg and a motor to fly. I really like making props, not least because they give life to the model. The prop does look a touch on the small side on the model (it's only slightly over scale diameter) but it ought to do something useful. I've set a 33° pitch at 75% radius. I'll be starting with a 7/32" motor cross-section. I'll go from there.

The prop on its own weighs 2.5g - I'd forgotten how light these things are. That means putting lead in the spinner, but there's hardly room for the freewheel let alone ≥ 2g of lead. Weight in the spinner is about 20mm ahead of weight stuffed in the bottom of the nose cowl - however, the bottom of the cowl is a good bit lower down, where weight will aid stability. I guess it'll go there.

Stephen.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Indoorflyer on December 29, 2018, 03:20:45 PM
That's a beautiful P-47 Stephen. Always liked the shape of the "razorback". There sure were a bunch of different models; which "suffix" version are you modeling?


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: FreeFlightModeller on December 29, 2018, 04:45:54 PM
Lovely job Stephen ... and the weight does sound good.  :)


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Work In Progress on December 30, 2018, 07:02:15 AM
There sure were a bunch of different models; which "suffix" version are you modeling?

It is a P-47D-23-RA , serial number 42-27910, of the 57th Fighter Group in Italy, flown by Major Gil Wymond.
You can see it in this original colour WW2 film: start at about 12.30 for the Thunderbolts.
https://www.youtube.com/watch?v=kR6lWSIWUOA


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Pete Fardell on December 30, 2018, 07:11:04 AM
It's looking beautiful, Stephen. What a classy little model! For such a big fat plane the P47 had real grace, and you capture that perfectly.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: OZPAF on December 31, 2018, 07:25:03 PM
Well done - yet again Stephen. That shot from underneath really indicates how well you have captured the detail - nice fairings and blending into the fuselage.

John


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Prosper on January 03, 2019, 06:58:09 AM
Quote from: Pete Fardell
For such a big fat plane the P47 had real grace,
Like a tuna fish.

Quote from: Work In Progress
It is a P-47D-23-RA , serial number 42-27910, of the 57th Fighter Group in Italy, flown by Major Gil Wymond.
Thanks WIP. He got up to Hun Hunter XVI. It's amusing to think that he might have written-off fifteen Thunderbolts before they realised what a liability he was and gave him a desk job. . .but I suspect the truth might be more to do with the fluidity of the war at that time and the sheer number of aeroplanes that the US was churning out.

The P-47 has flown [cheesy grin]. It's still lacking that last round of detailing and decorating though.

I flew it a few days ago in a light but shifty breeze, and at first I was very worried about the [lack of]spiral stability, but I think maybe it just needed some general basic trimming because after a few flights with 60 or 80 turns it was managing okay. I wasn't learning much because of the breeze and the model was soaking wet so I quit.

This morning the grass is not so wet and the air as good as still so I put 140 turns on and the model did a long extended glide, just missing some tree stumps hidden in the rank foliage. I then fetched my camera and got this video (https://youtu.be/pmHzaG6URNI) after two failed attempts.

I'm having trouble launching this thing - my fingers hit something. I don't know if it's the tailplane or the flaps of the turbo wastegate ducts (or whatever those flaps on the rear fuselage are). It's very irritating as the model veers off sharply and noses in to the ground quite determinedly. The prop blades are none too strong, because my recent purchase of hard 1/32" balsa. . .isn't that hard, TBH. . .but it's all I've got at present. Anyway the model is landing/crashing into a soggy mat of dead grass and weeds - could be worse I s'pose.

So although I left the house with camera and 150 turns wound, I can't give the turn count on the video clip because of the two failed launches, after each of which I wound on some more turns estimated to make up the lost ones. It will be close to 150.

The propeller still has its 33deg pitch at 75% dia. I make that a P/D of about 2, but I kind of made up the formula from first principles so knowing my maths acumen, my answer could actually represent the number of prop blades divided by the number of legs I don't have to stand on, mathematically-speaking. The video-flight model weighed 39g plus the water it picked up in the previous crash-landings. 39g gives a wingloading of 0.08g/cm2 or 0.52g/sq inch, so Tom Arnold's prognosis was spot on tho' I think it's carrying a lot less rubber than he anticipated! The rubber is a 22" loop of 7/32" Tan SS, well-braided. That gives a hook-to-peg of less than 3, so there's room for more rubber if the model merits it.

That's all the flying until I have a proper field available. In the past I've smashed many a model in trying to trim them for high-turns circling flight on the basis of innumerable low-turns flights, whereas the only sensible way to go is to trim them for hi-turns circling flight by er, winding on hi-turns, which needs more flying room. Having said that, I did manage the trick with my Leopard Moth mockup, but then I didn't really mind how many trees that one smacked into.

Stephen. P.S. just checked the link and see that Utube has completely crunched the video as usual - sorry about the poor quality.



Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: vtdiy on January 03, 2019, 02:47:44 PM
That looked wonderful!


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: vtdiy on January 03, 2019, 03:09:21 PM
Reading your comments Prosper, I tried figuring the P/D and got 3. But I'm new to it and may have that wrong.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: LASTWOODSMAN on January 03, 2019, 04:05:59 PM
     Hi Stephen.    Thank you for the great flight report, and video, that I watched several times.    Your mighty "Jug" Republic P-47 THUNDERBOLT looks fabulous, flying in your nice little forest glen ecosystem.  Many times I too have also not been learning much, because of an increasing desperation to fly in too "breezy" of conditions.  I have also gotten very soggy, water logged tissue, from landing in morning grass that is always heavily laden with dew around here.
     I also find launching to be very tricky business.    One must try to start with as perfect of a launch as possible.    My most embarrassing launch hit my hand with the rudder/stab, breaking it completely off,   :-\   with the rest of the plane somewhat flying away to an eventual crash with a lot of rubber turns left on the motor,  right in front of friends in the distance, that I was trying to impress and show off too.   :-[
     Is your prop hook to rear peg less that  3 Inches ?    And what is the length of your  "well braided" motor?
     Here is a snip pic of your P-47 Jug, that sure looks real against that bleak winter bush background.   :)

LASTWOODSMAN
Richard


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: OZPAF on January 03, 2019, 06:48:09 PM
Very promising Stephen.

John


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: flydean1 on January 03, 2019, 09:58:12 PM
You may want to flatten out that prop.  It will make the model easier to trim, and you don't care about duration anyway, just flight realism.  It should easily take two loops of 1/8, but again, duration isn't the goal.  P/D of 1.2 would be better IMHO.

Some nice twice head high circles, and the imagination supplying the sounds of that big round engine rumbling along.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: vtdiy on January 03, 2019, 11:48:45 PM
Just to show how I got a P/D of 3, (please check)

Pitch = 2 x π x (distance from hub) x TAN(angle of the blade)

In this case, with a 7" prop, the angle was set at 75% (or 5.25" out from the center)

Pitch = 2 x π x 5.25" x TAN(33 deg)

Pitch = 2 x 3.14 x 5.25 x 0.65

Pitch = 21.4"

with a 7" diameter prop:

P/D = 21.4"/7"  = 3.06


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: cvasecuk on January 04, 2019, 06:52:49 AM
Distance from hub is half of what you have used, so pitch is 10.7" and P/D is 1.5 which is not too bad!
Ron


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Prosper on January 04, 2019, 07:21:56 AM
Ah, I see, so it's the full prop diameter and not the diameter at the station where one's chosen to measure the blade pitch angle. Thanks Ron, yes that gives 1.5 which is quite a humble sounding P/D.

Quote from: flydean1
. . .and you don't care about duration anyway, just flight realism. . .Some nice twice head high circles, and the imagination supplying the sounds of that big round engine rumbling along.
Well I do care a bit about flight time :D but it's not the only consideration certainly. I may find myself  reducing the pitch if the model lands with lots of turns on board or if it's untrimmable at high power. Now I just have to wait until the grass grows in Spring. . .

Stephen.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: vtdiy on January 04, 2019, 09:13:26 AM
Distance from hub is half of what you have used, so pitch is 10.7" and P/D is 1.5 which is not too bad!
Ron


Ah, yes! Thank you!

(2.625" instead of 5.25"   -- 75% of radius, not diameter)


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: tom arnold on January 04, 2019, 06:43:32 PM
Stephen, your dilemma of having to have a big field to trim for max performance is solved pretty easily by going to a torque meter for winding instead of counting turns. I found myself in your situation many times prior to a contest and then the contest is where I had to really do my trimming with the expected miserable results. I found by using a simple P-30 size torque meter I could trim my model almost completely in the small field and do the last 1% at the big field. What I would do is load a motor only slightly longer than the fuselage such that the prop would hang out just a bit (kept me from having to constantly fish the motor out of the fuselage after a flight). It also helps to have a motor that you know is a little too thick just to not have to hassle with broken motors as you trim. Then I start trimming with a low torque.....say 2 in-oz. When I get the flight pattern I want, then  I go up one in-oz and repeat the trimming process. You keep going up one in-oz at a time until your previously well-behaved model starts acting wild and crazy and threatening to re-kit itself and you cannot trim it out. It seems to be flying the razor edge of destruction. It is telling me it is over-powered at this point and by backing off an in-oz, it turns into a kitty cat again. Now I know the sweet spot for flying...let's say 5 in-oz....no matter what size motor I have in it. This ends the small field testing. Now at the big field I want to know the max performance out of it so I load in a longer motor and wind to....you guessed it.....5 in-oz as anything more is overpowered no matter what size motor is in the airplane.

OK, there is a little more to it at this point. Because you are now hauling around more motor weight, you will have to sneak up a little on torque, but that is easy to do, until you see it flying like at the small field. Because you also have been using a slightly thicker motor to avoid breakage, you can now cut down on the weight by putting in a thinner motor but you always wind to that sweet flying torque that you have determined previously. Winds are really irrelevant as you are cranking in the max winds you can at the sweet spot of torque and you can't get any more in so the number doesn't mean much. There are a number of simple torque meters on the internet and I made mine in an evening's time.  If I change the prop, I need to start at the beginning of the process but things go a lot quicker the second time around.

https://www.fullsizeplans.com/images/nffs/TorqueMeterKothe.pdf        I make mine from 0-12 to 20 in-oz for a 24" span airplanes with an 8" props.

Beautiful model and good luck no matter what you do.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: TimWescott on January 04, 2019, 08:24:29 PM
Tom, a question.  It's theoretical for me because I'm not smart enough for free flight: couldn't you ballast the plane up to the heavier-motor weight for your small-field test flights, so that when you went to the heavier motor all was equal?


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: flydean1 on January 04, 2019, 11:06:59 PM
Not if your hook to peg distance is evenly distributed fore and aft of the CG.  Like Tom, I frequently use a test motor of twice the cross section from what I plan to use eventually.  The other advantage in addition to not having to worry about breaking the motor is that the winds run down really quickly and the model doesn't go so far. ;D


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: tom arnold on January 05, 2019, 09:31:14 PM
Tim, you can as long as you keep the CG at the same point. My only hesitation at that is I like to keep the plane as light as possible during test flights just to keep the damage down. Once I have confidence in the flight path, I can start loading on motor weight. Flydean's practice of centering the motor over the CG is a great idea and keeps the process of adding a longer motor a simple one. I test glide without prop and motor for the same reason of limiting any damage as the plane floats so well then and the trim settings are the same for heavier weights.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Prosper on January 06, 2019, 03:38:59 AM
Tom, Flydean 1, thanks for the info. I did try the short motor highly-wound idea some age ago but dropped it because I wasn't convinced it was 'like-for-like'. What I was missing was the torque meter of course. Now I have the .pdf with the secret formula I will try a torque meter. I hadn't considered one previously because it would interfere with the cozy arrangement for winding which I've become used to since I started on the aeromodelling dodge, but perhaps it's time I took a peek outside the comfort zone.

I think I'll play with this idea but not with the Thunderbolt. My scale models are trimmed to circle left under power, so the turn slackens and eventually becomes a straight or a right-hand as the motor runs down. I presume that flight pattern is the same with a short but highly-torqued motor, so the risk of the model straightening or S-turning into something very hard is still there, if I understand right.

Stephen.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: flydean1 on January 06, 2019, 10:27:58 AM
When possible I trim for a right pattern which will tighten up as rubber runs down, keeping things between the walls.  However, low wingers are nearly impossible to do that way.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Prosper on March 24, 2019, 11:53:55 AM
I added some final touches to this after a prolonged spell of windy weather. There's no end to the detail that can be forced on a model but that's about it for this one I expect.

I flew it yesterday and managed to crash it into a small tree - luckily it was a young hazel (very forgiving usually) and even luckier the hazel stopped the model from hitting a brick wall which was the next stop. A couple of gun shrouds were the only casualties. They were easy to replace.

If I could get into the middle of the bigger flying field I use, then I'm ready to start ramping up the turns to see how the P-47 flies, but I can't use that field at present.

Anyway, the couple of 250-turn flights it managed were dignified and self-reliant looking efforts, so I'm hoping it'll be a good flier. 
 
Stephen.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Pete Fardell on March 24, 2019, 12:06:37 PM
Lovely lovely lovely!


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: MKelly on March 24, 2019, 01:36:58 PM
Beautiful jug Stephen!

Mike


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: TheLurker on March 24, 2019, 02:40:09 PM
Lovely lovely lovely!
Wot 'e sed.  Wiv knobs on.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: cast_off_vortex on March 25, 2019, 04:24:21 AM
Now that's Farmingdale Thunder. Really super effort!


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: OZPAF on March 25, 2019, 04:29:46 AM
Is this the man who said that he couldn't cover well with tissue? :) Very clean effort Stephen.

John


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Yak 52 on March 25, 2019, 05:25:46 AM
Looks amazing!  8)


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Prosper on March 25, 2019, 05:53:53 AM
Fanx fellers. I'm pleased with it, though as always the camera flatters it. Anyway, I've learned a lot, not least about waterslide transfers and prepainted tissue. I hope to employ this nollidge elsewhere.

Here's a snap of Farmingdale Thunder next to its buddy Grumman Ironworks. The P-47 model  has the much higher wingloading of the two, but that's as I expected and wanted, in fact, for flying in limited areas. I hope it'll put up a bit of duration anyway. . .needless to say will report when I can fly it! I see the F6F has lost its gun shrouds on one wing - that must have been a hangar rash incident as it hasn't flown for many a month.

Stephen.



Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: vtdiy on March 27, 2019, 10:34:39 PM
Beautiful plane, Prosper.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Prosper on April 29, 2019, 05:23:36 PM
Thanks vtdiy.

The grass was cut on my bigger flying field today, so I flew the P-47, keeping below 250 turns. It already has a new prop blade - when making multiple blades simultaneously there's often a 'runt of the litter' which is weaker than the others and this one  will always break if there's any breaking to be done. With the new blade, all four do a good job of shock-absorption. The model lost a couple of gun shrouds and said blade when flying onto rough ground a few weeks ago.

Anyway today's flights were a bit worrying, in that with a good launch the model lopes off and covers a lot of ground with relatively few turns. As the old transport pilots wrote in their autobiographies, you can almost count the blades. With say 200 turns left of about 1400 fully-wound, I would expect the model to be flying straight or even turning right, after its majestic long flight of left-hand orbits (:D). So to wind on just 200 turns and see it fly way off and land in a soft nettle patch just a metre from hitting stones and a fencepost (wince), has me nervous. It might need lots of space to get to the fully-wound fully-trimmed goal without danger. Launching is awkward. There's something wrong with the grip - always catches something and skews the model on launch. So I've come to hold it further back, just behind the turbo wastegates. That works, and the strength of the fuselage is adequate to bear the grip despite no cross-bracing, but it's so far behind the CG that a really fluent motion is needed (at least with low turns) to achieve a good launch.
 
Stephen.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: OZPAF on April 29, 2019, 08:37:14 PM
I wonder how a underhand launch would work? Hold it over the wing root and launch underhand? Of course down here I would just launch it inverted :)

John


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Prosper on April 30, 2019, 02:22:21 AM
How dare you sir. . .I have never done anything underhand in my life. . .oh, oh, I see. Well, it's a novel thought John. Acting it out I can see the possibility of the port wingtip striking my thigh as I launch, and looking down on the model it would be hard to judge its attitude - but practice normally cures such issues. It might work well when the turns are high giving the model lots of thrust. What I'd like to do first is understand what's happening during a conventional launch. I need someone standing on the other side with a very high frame-rate camera.

Stephen.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Prosper on April 30, 2019, 04:44:02 PM
The breeze was L&V by late afternoon so I flew the P-47 on more exploratory 200 turn flights. The model was

*Headstrong
*Wilful
*Insouciant
*Unpredictable
*Petulant
*Wayward
*Flippant
*Downright mulish

Like all believers in home truths I decided to put my foot down and take it in hand. First I mended another broken prop blade (this one had fractured in the normal way, where there's a very jagged, splintery break which has enough surface area for a good-as-new fix), then I doubled the width of the elevator and rudder hinges (thin aluminium), because they were just too weak and every time the thing landed they needed resetting. I don't think they could have moved under aerodynamic forces, and so cause unpredictable flights, but now I know they won't budge.

Then I added nearly a gram of noseweight, not because pitch problems were much in evidence but just to rule them out for now.

Then, because I could see there was something wonky about the yaw/roll relationship, I added a gurney flap. This is my first ever (nearly all my models have ailerons) and it's an arbitrary strip under the port wing, 0.5mm balsa and about 1mm wide (as in 1mm projecting into the airstream). I don't know if the same strip over the stbd wing would be better drag-wise, but anyway the big old Thunderbolt turned from a mule to a mild old donkey.

The idea of a gurney flap isn't new to me - the RAF (and presumably every other airforce/flying club/manufacturer etc) doped cord to the trailing edges of their control surfaces (when necessary) back in the age of the archaeopteryx and pterodactyl. But I think this is the first I've installed, unless a wedge under a CLG wing counts as the same thing? Very effective.

I went straight from clumsy 200 turn flights wound by hand, to a 500 turn stretch wound flight with camera (https://youtu.be/cVcww5Bt3KI). Note the nose-up attitude. . .perhaps I'll be able to shed a bit of that noseweight now.

Stephen.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Pete Fardell on April 30, 2019, 05:00:36 PM
Stephen, that is lovely!

(To be honest, I'd happily watch a video of your field even without the superb model, just for its atmosphere of bird song and bucolic tranquility!)


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Prosper on April 30, 2019, 05:48:35 PM
Pete, I'm glad you thought that. . .in this 'grab' from the video. . .if you get rid of the power lines (mains electricity and water arrived here only in 1963) and exchange the wide metal gatery bottom right (necessary for huge modern agricultural vehicles and attachments) for a wooden gate, couldn't that be a picture of a US 8th AF Thunderbolt taking off in 1943? The English-based Thunderbolts were nearly all olive drab I think but never mind. When I was a kid there was lovely long, low barn right below where the model is in the picture, made of local stone, local wood and with a Welsh slate roof. The barn owls liked it as well as me. No barn owls any more.

Stephen.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Jack Plane on April 30, 2019, 06:33:51 PM
Gurneys are real magic. Lovely video.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: flydean1 on April 30, 2019, 07:30:40 PM
Stephen, I wouldn't touch it!


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: OZPAF on April 30, 2019, 07:42:38 PM
That looks spot on to me Stephen. Nice cruise and glide as well. I agree with Peter - your vids are always full of relaxing bird sounds. Just what I need for breakfast reading. :)

John


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: LASTWOODSMAN on April 30, 2019, 09:37:19 PM
     Hi Stephen.  I have been watching, and listening to your birds, over and over and over, on your P-47  Thunderbolt Flight Video above  in Reply #140  - very inspiring - ethereal really ...  :)   Thanks for the still pic too.   That is why I like flying scale planes outside (actually it is my only  option   :-\  ), -   and yours looks so real ...  :o   I can't remember asking you, but, about how big is your little nature paradise flying field ?   My  Cricket field is slightly oval,  and about  130 yards by 110 yards.  
PS  What happened to your Barn Owls?

LASTWOODSMAN
Richard


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: MKelly on April 30, 2019, 10:16:22 PM
Beautiful Stephen - I just watched that flight video about ten times.  The Jug just moves and looks right.

Mike


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: steveneill on May 01, 2019, 01:37:31 AM
Perfect!


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Prosper on May 01, 2019, 11:59:32 AM
Thanks for the very kind comments folks. I'm always aware of my luck in having such a flying area on my doorstep. I have to limbo through a post-and-wire fence (so that's my callisthenics for the day done too) and I'm there. The farm hard by which owns the field has a way of making lots of noise - clanging, banging, revving and such, and the wind can bring over the noise of a major road not far away, but yes it's often very peaceful too, as the video shows.

Richard, the plot of land which is exclusively 'mine' - as in belongs to the family - features an uninterrupted rectangle roughly 60yd by 45yd, but if you look at the area with only two or three trees in it then that's mebbe three times as big, and there are many small irregular spaces all around, allowing for a sort of Russian roulette flying which I'm happy to undertake with 'expendable' models, and of course it's good for initial trim flights of any model. Something like the P-47 with more than 100 turns on board is probably going to hit something hard. The bigger farm field is about ten acres but the field's shape and houses round some of the border means that much of that acreage is unusable.  This certainly affects - even dictates - the kinds of model I can fly, but there are several lifetime's worth of models that I could build and fly within those space limitations!

More video when I can wind the Thunderbolt up.

Stephen. PS Richard, the barn owls succumbed to habitat loss - nowhere to nest and not enough prey. 'My' kestrels are back again this year though.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: John Webster on May 02, 2019, 04:44:06 AM
Congratulations Prosper. That is a very fine looking Thunderbolt and the flight video shows a nice smooth flight pattern.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: dputt7 on May 02, 2019, 05:10:13 AM
  I missed your Vid and have just caught up, Very impressive, thanks for going to the trouble of posting.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Don McLellan on May 02, 2019, 11:32:17 AM
Beautiful flight Stephen!  If you had included the sound of a big thumping engine, it could have been mistaken for the real thing.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Prosper on May 05, 2019, 02:51:22 PM
Thanks John, Dave and Don.

Wahay! I got in two unexpected flights just now. Conditions near perfect. I hadn't broached the sidethrust matter before, but deciding to fly with a good percentage of full thrust, I thought it wise to add a TLAR 3° of right thrust. There is no deviation up or down - thrust line along the fuselage datum. I tweaked a touch of left rudder to anticipate the effect of the right-thrust - as in trying to keep it safe and not wandering off to the right into hostile territory.

A 700 turn flight was nice but nodding into the stall so I tapped the top of the elevators and went back to the house to wind on 980 turns (about 2/3 of the safe max turns for the installed motor) and grab the Box Brownie, then back in the field I asked the birds to put on a bit of a song (https://youtu.be/cMl7jTxEisg).

I'm very pleased - I might even add the missing gun shrouds and paint the new propeller blade to match the others. What's more, as I turned to go indoors I saw that the whole demo had been scrutinised by the female kestrel of 'my' breeding pair, who was in a favourite treetop perch. The pair is fairly tolerant of my flying activities - I think they like a good larf.

Quote from: reply#140
. . .couldn't that be a picture of a US 8th AF Thunderbolt taking off in 1943?. . .
I just re-read that and realised that it could read like a flagrant boast. "Look at my maaaarvelous model, it could be the real thing in 1943". I didn't mean it that way at all - after Pete's remark about bucolic tranquility I was trying to suggest that the countryside could almost seem as peaceful and rural as it would have been in 1943. Bit of a red face.

Stephen.



Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Jack Plane on May 05, 2019, 02:57:46 PM
Well pleased you should be Stephen!  That looks just right!

Jon


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: dputt7 on May 05, 2019, 08:40:12 PM
  Beautiful scale flight, much more enjoyable than a 45deg. climb into the clouds. Not knocking the duration style flight just my opinion.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: LASTWOODSMAN on May 05, 2019, 10:50:32 PM
     Another great video Stephen - nothing wrong with a flagrant boast when everything falls together - great model, natural scenery, perfect flight, birds singing,  sky with sun and clouds -  I hope the newbies are watching this ...   :D
     I'm glad you got your little "Kestrel" falcons back nesting in the same place every year.  Our Cooper's hawks are back, but I cannot find their new nest, as they change the nest tree every year.   We have the 22" Kestrels here in the park too,  nesting way up high in the lights of a baseball diamond field every year.  I also saw the 23" falcon - the "Merlin" falcon (or "pigeon hawk") -  flying around here a few times too.

LASTWOODSMAN
Richard


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Don McLellan on May 05, 2019, 11:39:47 PM
Hi Stephen,

Watched your video a couple of times and all I could think of was..........'wheels down, wheels down' at the end!  An exceptionally realistic flight.

Don


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Prosper on May 06, 2019, 04:36:29 AM
Quote from: Don McLellan
..........'wheels down, wheels down'
Ha ha - I like it, Don.

Quote from: dputt7
Not knocking the duration style flight just my opinion.
I prefer the leisurely flight pattern too Dave. Many of my scale models fly too fast to look 'right'.

In terms of duration, I wonder how the exact same model would compare, with identical rubber motors installed - one driving a low-pitch two blade prop to blast the model into orbit, and the other to drive a high-pitch low-rpm propeller as seen here? It's a given for non-scale duration models with folding props that the Cape Canaveral method yields better results, but for a scale model that glides like a hollowed-out brick, maybe not? I may try this when the model is at the end of its life, but I'd worry that the winds higher up would blow it out of the safe area. The model as seen here does achieve some altitude but I use full zoom on my camera which makes it look like it's just over head-height.

Now I have to wait on the weather, and hope for full-turns flying opportunities before the grass gets too long to trample on. . .though I might freeze to death first; this must be the coldest Spring of my lifetime.

Stephen.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: steveneill on May 06, 2019, 11:24:53 AM
Fantastic thanks for inspiring me this morning! Beautiful flight!


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: steveneill on May 06, 2019, 11:31:04 AM
Stephen it moved me so much I put it on our website to inspire some of my lazy squadron members to get off their keesters.

It would be nice to have a last name to go with this so people know who did this wonderful build.

https://theventuramodelaviators.home.blog/


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Prosper on May 06, 2019, 06:13:49 PM
Thanks Steve,  I'm flattered. My name is Stephen Thorpe, tho' most people call me Steve. I'm disturbed to hear that you have some lazy squadron members - don't you have any 'encouragement' resorts like fatigues, or hard labour, or firing squads, etc? Tut tut.

Stephen ;D.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: OZPAF on May 06, 2019, 08:28:56 PM
Majestic scale flight there Stephen. Possibly climbing to the position of best performer in your hanger?
Congratulate the birds for their singing as well.
Is this early morning? The field looked just right - the grass possibly a bit out of scale :)

John


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: steveneill on May 07, 2019, 12:58:12 AM
Steve not at all. What you did and how you did it is amazing.

No Steve nothing like that I live in the part of this...well country where we don't do such things. It's called California and we are kind of our own country. LOL!

We say things like, "Your all individuals. You don't need a messiah". Got to go now while I help my confused friend figure out how he'll jestate the fetus. ;)

But seriously, your work is inspiring me and I'm building a Jody next. I have the Volare kit and it's been haunting me. Seeing your video pushed me over the edge as soon as I finish this American Eaglet.

Steve (that's it, we should all be Steve it avoids confusion or Bruce) ;)


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Prosper on May 10, 2019, 05:14:06 AM
Quote from: OZPAF
Possibly climbing to the position of best performer in your hanger? Is this early morning?
Mid-evening, John. The evenings get very long at this time of year. Yes, as a performer it must be 'up there' to use an apt phrase. I doubt it will get anywhere near the F6F I made a couple of years back. . .but it does seem capable of decent flights at fairly low altitudes, whereas the light F6F climbs into breezier air and tries to fly to where I couldn't retrieve it. . .

Quote from: steveneill
It's called California and we are kind of our own country.
6th biggest economy in the world, or somesuch? I've been to Oxnard, Camarillo, Santa Paula - all Ventura County IIRC. Very nice neck of the woods.

I got another two flights in last evening, when the weather suddenly went limp after a very cold wet few days. The flight I recorded, https://youtu.be/n1xBT0fACVQ, has nearly max safe turns for the motor, and power stalling is evident. I stood fully upwind for the launch, next to a mature oak, and to see the model falling off to the right every time it slowed down was a bit worrying. . .In the event it turned out well as the periodic right-turn course corrections kept the model's ground track close to the camera. And it didn't hit anything.

I expect there's some more duration possible: the air was as good as 100% RH, the model was wet and wrinkled from its first flight, and was one or two hundred turns short of the limit. I might have put on full turns but the motor felt solid in the 13° temperature where I wound it so I chickened.

The model appears to be missing its radio antenna on the spine - it's not missing, but somewhere down in the bilges of the fuselage, due to clumsiness while getting the model from the winding stooge.

I've had another bash at re-encoding videos to suit YouTube. My internet connection is dead slow, so the YouTube 'auto' resolution offered to me is very low. I hope people with faster connections can view or download the vid in 1080p. At that resolution it's still degraded from the source video but better than my uploads of previous years, which typically showed a gaggle of pixels moving against a background of different-coloured pixels.

Stephen.



Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: OZPAF on May 10, 2019, 05:45:53 AM
The power stall is very slight Stephen and that cruise and landing would be hard to beat. not bad duration either!
Strangely I tried to go back and re watch the video and I got an error message?

John



Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Prosper on May 10, 2019, 05:58:24 AM
Hi John, I'll keep an eye on the link, thanks for letting me know. I made this video 'public', maybe that changes something. Most videos I upload are 'unlisted', meaning they can't be found by general searching.

Yes the duration is about where I expected - better in fact. I think I'll coarsen the blade pitch a bit to see if that cures the stalling.

Stephen.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: steveneill on May 10, 2019, 10:16:14 AM
Steve I love it here. Beats the hell out of LA county, Los Angeles where I lived for 40 years to be close to the film studios where I worked.

I was able to view the video just fine. Here at the house our connection is decent. At my film studio 15 minutes from here it just terrible and difficult to get a faster connection as Ventura is a smaller town and a bit backward in that way. But we do have beautiful countryside, beaches and a slower pace. Good trade off.

What is next for you is my big question? I'm going through that currently. You have motivated me to build a warbird next.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: tom arnold on May 10, 2019, 11:55:50 AM
Beautiful airplane and great flight. Why would increasing the blade pitch cure stalling though?


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Jack Plane on May 10, 2019, 02:34:22 PM
Beautiful airplane and great flight. Why would increasing the blade pitch cure stalling though?

Slow the airspeed and reduce the lift?  (I'm not very good at this, still learning, just suggesting...)


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: OZPAF on May 10, 2019, 08:47:39 PM
Quote
Why would increasing the blade pitch cure stalling though?
.The increased pitch would load the prop a bit and smooth the power delivery thus helping to eliminate the initial mild power stall - at least I think that is what Stephen may be considering.

Quote
Slow the airspeed and reduce the lift?
Possibly more a case of slowing the initial acceleration.

John


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Prosper on May 11, 2019, 05:59:09 AM
Hullo Tom,  Jack Plane and OZPAF are right. I mean they're right in reading my mind - let's see about the outcome of a higher-pitched prop!

Interesting point about acceleration John - I did wonder whether the stalling evident in the video was simply caused by a bad launch, taking a long time to damp out, and decided not to change prop pitch until I'd flown the model some more.

You've just reminded me that I forgot ;D. Yesterday I increased prop pitch to 38° at 75% radius, which is about P/D 1.9. The weather stopped me from flying but a high-turns static run gave an average rpm of 840 which is very low indeed. That might increase to say 1300rpm in forward flight. I'm looking forward to trying it. The weather forecast suggests a couple of flyable days in the offing.

On the cosmetic front I painted the bare prop blade and added two new gun shrouds to the left wing, but the radio aerial mast is going to be tricky. It fell out of the nose after I'd shaken the model enough times (a lot of times) and it has the mounting block attached to it, i.e. there's nothing inside the razorback to support it. This will require some surgery.

Stephen.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: flydean1 on May 11, 2019, 06:20:11 AM
The more pitch and/or diameter, the more tricky to trim a rubber model, especially a low-wing with scale or near-scale dihedral.  My rule of thumb on the pitch oscillations:  If it dampens out, the force setup is OK.  Concentrate on a smooth launch getting the model in the air on speed, and not too nose high.  A slight increase in down thrust might make it less critical as the effect will decrease during the flight and the launch might be less tricky.  If the oscillations increase toward the end or don't dampen at all, some nose weight (shudder) is required.

Resist the temptation to cure all pitch oscillations with "demon lead".  If it smooths out toward the end, you don't need any more.

Observing your excellent Thunderbolt, I would stick with my original comment:  Don't touch nuttin".  I would even stay with the same rubber cross section.  If your rear peg location is well forward,  you could put in a longer motor.  However, UK FF Scale competition is not duration based, but flight realism based.  Were it not for the birds chirping, I would swear that P47 is circling the field for landing, the R2800 rumbling softly, or I'm hiding in a ditch alongside a road, and that thing is about to roll in on me, I being the Hun it is Hunting for! :o


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Monz on May 11, 2019, 07:31:55 AM
Hi Stephen, those flights are stunning! I'd go with Mr Blast Tube above  ;D Maybe a teeny amount of down thrust just to see, but probably most importantly, a clean launch.

Your videos look like 40's colour film which just adds to the beauty of the model in flight in my opinion. Look forward to some more.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: ironmike on May 11, 2019, 10:06:08 AM
flydean is right I would leave alone and add turns and enjoy.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Crabby on May 11, 2019, 10:34:53 AM
I'd go with Mr Blast Tube above 

HA HA HA Monz you just slam dunked my funk!    Yes Prosper! great looking in every aspect! Of course everyone's dead on with the "leave it alone" advice, but where's the fun in that? Haven't you even cartwheeled that thing yet?


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Monz on May 11, 2019, 10:58:15 AM
I'd go with Mr Blast Tube above 

HA HA HA Monz you just slam dunked my funk!    Yes Prosper! great looking in every aspect! Of course everyone's dead on with the "leave it alone" advice, but where's the fun in that? Haven't you even cartwheeled that thing yet?

 ;D


Stephen, you do know you also have an opportunity for some scale prop balancing with this one, I mean, if that new prop blade you put on is slightly heavier than the rest...

(https://i.imgur.com/NRQTnin.jpg)


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: flydean1 on May 11, 2019, 04:22:32 PM
Mr. Blast Tube???  Really Monz... ;D  Am I acquiring a reputation??? 

Possibly better..."Move yer peg forward and use a blast tube". :) :) :) 


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Jack Plane on May 11, 2019, 04:32:42 PM
I bet matey-boy above had a blast!  ;D  I presume he put that hole in himself?


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Monz on May 11, 2019, 05:15:21 PM
Mr. Blast Tube???  Really Monz... ;D  Am I acquiring a reputation??? 

Possibly better..."Move yer peg forward and use a blast tube". :) :) :) 

Well, I do move the peg forward  ::)

I bet matey-boy above had a blast!  ;D  I presume he put that hole in himself?

That was from an enemy cannon shell, he flew it back home like that. Vibrations must've been unreal. Testament to the Jug's strength.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: flydean1 on May 11, 2019, 10:12:40 PM
Monz,  the first time you have to repair a dismembered model from a motor that popped on moderate hand winds, you'll become a convert. ;D

On the Jug's strength:  I did read about the cannon shell thru the prop.  Evidently it made a distinctive whistle.  Wildest Jug story I read was one guy got in a really bad dogfight, but after he scored a couple kills, AAA fire hit his engine and blew the top off about 3 or 4 cylinders on the front of the R2800.  He had lots of altitude so set off for Switzerland with thoughts of sitting out the rest of the war in comfort.  Then he remembered the day's score would put him ahead of a squadron rival, and the evidence was in his gun camera.  Well, he turned around and flew back across Germany, across France, across the Channel and landed at his base.  The pistons of the damaged cylinders were flailing in the air all the way!

The A10 Thunderbolt II evidently inherited the Jug's sturdy reputation.

All you folks have a great day at Old Warden--and take pictures for us in the "colonies".


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Prosper on May 12, 2019, 04:17:01 AM
Quote
. . .where's the fun in that?
I tend to agree - this one hasn't cartwheeled yet, thankfully, but I get a lot of fun from trying every trick to get one over on Isaac Newton and his silly laws of gravity. Who let him pass those laws, anyway, without discussion or consultation? I often keep tweaking my models even when they've probably shown their best possible performance.

Quote
. . .I presume he put that hole in himself?
I had to check that one too - it looks so staged. I thought he was still wearing his overalls from the workshop. But it seems to be true. It reminded me of the yarn some ex-RAF engineers used to repeat occasionally, of the erk (mechanic) who stepped through the idling prop of a four-engined bomber to fetch something, realised what they'd just done, and fainted with shock. I think that's impossible, but ack-ack shells move much faster than erks, so I could just see how a shell might go through a blade so fast that the engine just took a jolt. There was a freak helo crash when the cap of an exploding oil drum on a film set hit the rotor, IIRC. So it's probably not safe to assume that it's OK for cannon shells to hit your prop.

I may get some flights this evening. That grass is growing longer by the minute. Out of bounds soon.

Stephen.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Prosper on May 12, 2019, 12:55:07 PM
.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Jack Plane on May 12, 2019, 02:48:32 PM
 ;D I love the way you've painted blown-out metal and a lovely blue sky with puffy white clouds on your prop!


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Monz on May 12, 2019, 02:54:19 PM
So good Stephen! Love it  ;D ;D ;D


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Don McLellan on May 12, 2019, 07:07:02 PM
Great pic Stephen!  How long did you have to wait to get the clouds to line up?   ;D


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Prosper on May 13, 2019, 02:48:08 AM
Quote from: Don McLellan
How long did you have to wait to get the clouds to line up?   ;D
I'm not quite sure what you mean Don? I just turned the prop until the blade with the great big hole in it faced the camera, and pressed the shutter. Took no time at all. Oh look, are those birds visible in the sky through the big hole in the blade?

Oh well. The flying that evening turned out a bit less whimsical than 'blade art'. The grass in the field is already over ankle-height on average and I was feeling a bit guilty about stepping on it, so I didn't walk as far into the field as I shoulda. The model had full turns for the first time (except a previous static run), 1440 turns which is a bit over 80% of the theoretical breaking turn for the motor. I thought the extra torque would make sure it kept to a left hand circle, but the motor juddered and shook the model right from launch, with the power output changing up and down, so the model wandered off course without having gained much height in total, drifted by the slight breeze, and by the time it had settled in a predictable left-hand orbit (I guess the clumps in the motor that must have caused the bad vibration were gone by then) it was low and near the field boundary. It did find a pretty spot to hit, and I first thought it was all intact, but the left wing leading edge was concertina'd. That'll take some work. Anyway, no more flying until the grass is mowed again.

Stephen.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Pete Fardell on May 13, 2019, 04:16:19 AM
It did find a pretty spot to hit, and I first thought it was all intact, but the left wing leading edge was concertina'd
Maybe it was heading for the bird box hangar, but got distracted by the blossom. Talking of which, there was plenty of blatant clout casting going on at Old Warden yesterday. I caught the sun on my poor winter-white arms despite suncream applied. Does that mean summer's really here now?
And are you sure that the wing damage is not just more of your cunning trompe l'oeil? Well, maybe not but I'm sure she'll soon be ship-shape again. If you can't fly in that gloroious field for a while please do feel free to keep posting vids of it- even if they just show the grass growing!


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: ironmike on May 13, 2019, 10:02:30 AM
Aww gawd right where the 50s are, bummer.
Hope to see her in the air again Steph.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: OZPAF on May 13, 2019, 09:11:22 PM
Very inconsiderate of that tree not to move Stephen :)

John


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Don McLellan on May 13, 2019, 11:17:16 PM
Hi Stephen,

Further to my reply (#185), the real clouds almost line up with the clouds in the pic you've attached with your prop.  So, great camera work!

And, exceptionally bad luck damaging the wing leading edge on your Jug.  As a bystander, would appreciate some step by step advise on how you will make this repair.  And please understand, there is no rush to make the repair or post pics.  Only when you are ready.

Cheers,

Don 



Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Prosper on May 14, 2019, 03:16:03 AM
Quote from: Pete Fardell
are you sure that the wing damage is not just more of your cunning trompe l'oeil?
I wish! Both for what it would say about my artistic ability, and because there'd be no fixing to do. . .Yes, at last some sun and some warmth. . .

Don, reply 186, I was kidding, just in case that wasn't clear. I saw what kind of a weather day it was before doing the very hasty daubs on the blade. Getting the blue right is the problem - really 2 or 3 different blue pigments are needed and I have only one in acrylic ink. Yes I'll post on how I do the repair, though I've no idea at the moment, so it could be fun to watch. . .

Stephen.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Crabby on May 14, 2019, 10:40:08 AM
And please understand, there is no rush to make the repair or post pics.  Only when you are ready.

Yeah no rush,...take your time.... just hurry up!


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Work In Progress on May 15, 2019, 06:10:44 PM
Been working too hard so I am very late to say this, but that latest flight video is poetry in motion. Stephen, you are an artist, a craftsman and an engineer. Very well done.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Prosper on June 01, 2019, 03:57:40 AM
Thank you very kindly, WIP.

The flying field was mown again yesterday so I'm on the loose again - with nothing to fly :o. I was up early this a.m. and made a start on this repair.

Before touching anything I shone a strong light through the wing to see what was what. I couldn't remember how I'd built the wing. Normally with own-design S&T models, I make a sheet D-section at the front without a leading edge member of any kind, but this is a conventional wing with a leading edge member, only sheeted top and bottom. There's also a doubler behind where the gun shrouds are, because my original intent had been to set the shrouds into sockets.

Then I tugged the crushed stuff forward and saw that the underside is less damaged than the top. I cut out most of the damaged area and realised that I'd have to get the underwing pylon off too. I couldn't recall how I'd glued it in place but it came off with methylated spirits, and luckily this solvent didn't attack the particular acrylic I'd used for the yellow bits of the model.

That's where it is now. Accepting that there will be a certain weight gain, then the whole issue (as I'd guessed it would be) is to do with tissue anchoring. The broken and fractured timberwork will look after itself I expect, but what about the tissue? I really wanted to avoid overlapping tissue, but looking at what I've got here, overlapping tissue is certainly the quickest and perhaps the only sensible fix.

Stephen.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: TheLurker on June 01, 2019, 05:25:14 AM
Quote from: Prosper
...looking at what I've got here, overlapping tissue is certainly the quickest and perhaps the only sensible fix.
Make a virtue out of a necessity?  Overlap the tissue and use a 000 or 0000 brush to dot dark grey "rivets" to make it look like a field repair?  I can't find any images on "teh internets" to justify this, but...


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Prosper on June 02, 2019, 11:17:00 AM
Thanks for the idea Lurker.

First today I stuck down the free tissue by brushing wallpaper-type paste under the edges. Then I bevelled the two separated sections of leading edge in order to scarf in a new section. Yesterday I saw that the L.E. is a strip with the top and bottom sheeting wrapped around it which makes life difficult. The pink arrows show the steps in the new L.E. section to accommodate the new L.E. sheeting. Nothing about this work is quite square, so the two pieces of 0.4mm sheet had to be tailored to fit; first the bottom then the top.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Prosper on June 02, 2019, 11:18:46 AM
 I fixed a balsa tab (arrowed) under the inner edge of the top piece, to aid location. The arrow in the last pic shows a loose end of tissue which has been dangling in space until the fitment of the top piece of repair sheeting gives it an anchor. Getting that fixed down without a dent or wrinkle will be a trick.

There are a couple of tiny gaps that need filling then I can cover. I'm not in a hurry to finish this because it's been raining nearly all day, and the forecast is cold. . .wet. . .windy. Or is it just that I'm scared of fouling it up? Wet and windy, sort of?

Stephen.


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: Don McLellan on June 02, 2019, 08:08:10 PM
Hi Stephen,

Thank you for the pics showing the wing repair.  Very neat and tidy work.

Don


Title: Re: Little [s]Brown[/s] Natural metal Jug.
Post by: OZPAF on June 02, 2019, 08:25:02 PM
I like the way you have duplicated the structure in your very neatly done repair Stephen. I have seen people over the years resort to just throwing in a lump of foam or balsa in similar repairs - admittedly to larger RC models. Retaining the structural approach will provide a better strength distribution and is also more likely to incur a minimum weight gain.

Carry on Magoo :)

John