Logo
Builders' Plan Gallery  |  Hip Pocket Web Site  |  Contact Forum Admin (Account/Technical Issues)  |  Contact Global Moderator
August 19, 2022, 01:17:14 PM *
Welcome, Guest. Please login or register.
Did you miss your activation email?

Login with email, password and session length
 
Home Help Search Login Register
Pages: 1 2 3 [4]   Go Down
Print
Author Topic: Is Manhattan Cabin even flown any more?  (Read 17089 times)
0 Members and 1 Guest are viewing this topic.
Greg Langelius
Gold Member
*****

Kudos: 24
Offline Offline

United States United States

Posts: 668




Ignore
« Reply #75 on: April 09, 2022, 01:05:42 PM »

Back then (early 1990's), we would take our sheet C Paper and crumple it until the wrinkles were very small. Then, we'd very gently open it up and smooth it down as flat as we could make it. This technique allowed the paper to remain undisturbed when the humidity went through its swings.

When handling the C Paper during this process, surgical gloves helped to prevent the paper from absorbing moisture due to sweaty hands.

Greg
Logged

New knowledge is found by re-examining old assumptions.
DavidJP
Titanium Member
*******

Kudos: 47
Offline Offline

United Kingdom United Kingdom

Posts: 3,257




Ignore
« Reply #76 on: April 09, 2022, 03:17:50 PM »

A possible coincidence because a friend of mine mentioned Manhatten a day or so ago and an interest was emerging.  I knew little or nothing about the class and here it appears a much neglected design.  So I am beginning to feel I would like to try it.  I have used condenser paper (obtained from FF supplies) but was not impressed.  Some of the boffins claimed it was no lighter than Esaki and thus my personal choice - Dilly tissue. 

Where, approximately,  are you edgeworm?

My chum has a book with plans - not sure if it is Mr Williams.

Did you measure the mass attributes of Dilly, as to compare to condenser paper?

Just curious.

Best-
Dave


No - I took the details from the work of more learned chaps and which I think are set out in the online newsletter, in the advert for the tissue,  for SAM 1066.  The condenser paper I have was from FF supplies.  I am not skilled in its use so it could well be very good stuff but I am not qualified to judge.  Are there restrictions on the wood one should use because if you are properly serious I imagine the special timber from Greenman is what one should use.
Logged
piecost
Gold Member
*****

Kudos: 14
Offline Offline

United Kingdom United Kingdom

Posts: 677



Ignore
« Reply #77 on: April 09, 2022, 04:36:33 PM »

I don't think that there are any restrictions on the wood and don't recall if advanced materials (composites) are allowed. There is no need for Green Man wood, good model shop wood is fine. The challenging part is finding some nice quarter grain sheet for the propeller.
Logged
Gary Dickens
Gold Member
*****

Kudos: 14
Offline Offline

United Kingdom United Kingdom

Posts: 425



Ignore
« Reply #78 on: April 09, 2022, 05:08:27 PM »

Can someone point me in the direction of th UK rules please? No mention of the Manhattan class in the current indoor rule book.

Gary
Logged
DavidJP
Titanium Member
*******

Kudos: 47
Offline Offline

United Kingdom United Kingdom

Posts: 3,257




Ignore
« Reply #79 on: April 11, 2022, 07:10:32 AM »

Thank you piecost.  I am tempted to ask where does one find a good model shop these days but for me SLEC is within a short distance. I did toy with buying some wood from Greenman but having seen the quality of some bought by a chum who incidentally is rather a good modeller of small scale aeroplanes I felt it rather exotic for my present skills. And possibly away from the spirit of Manhattan. 

I would be interested to see the rules if you are successful Gary.  I think one or two other folk I know could be interested too. 
Logged
Edgeworm
Bronze Member
***

Kudos: 3
Offline Offline

United Kingdom United Kingdom

Posts: 12



Ignore
« Reply #80 on: April 11, 2022, 01:58:19 PM »

Hi Guys,

Your wish is my command....

The Manhattan rules were purged a few years ago as no-one flew the class; a situation I would be keen to reverse. Here are the UK rules from the last year they were included in the rule book. If they get re-instated, these rules will be put back in.

Manhattan Cabin

(a) An indoor duration model. Overall model length (maximum) without propeller 20 ins. Fuselage must be able to contain an imaginary box 2 ins x 2.5 ins x 4 ins within its maximum interior cross section at any one vertical station. The fuselage must have a clear plastic windscreen of at least 2 sq ins area. Motor sticks and diamond fuselages are not allowed. The rubber motor must be enclosed and supported by the fuselage.

(b) The propeller must be a fixed pitch all balsa type.

(c) All models must ROG, landing and take off gear must be a fixed and rigid 2 wheel assembly capable of fully supporting the model with the motor inside. Minimum wheel diameter 1 inch.

(d) An unbraced monoplane wing is required, mounted directly on the fuselage (no pylons or wing posts), maximum size 20 ins x 4 ins flat (not projected).

(e) Stabiliser dimensions must not exceed 12 ins x 3.5 ins

(f) Tissue or condenser paper covering is allowed, but plastic films are not.

(g) Minimum weight without rubber 6 grams.

(h) The rudder may not extend beyond the rear of the stabiliser

(i) A 4 gram model, as flown in the USA and other countries may also be flown. The specification is as above except that the wing may be mounted on posts or a pylon and that the minimum weight without rubber is 4 gram. When flown in the same contest as 6 gram models, the flight times of the latter shall be factored up by 10/7 to determine the competition score and placing in the contest.

Food for thought, hopefully.

Cheers,

Edgeworm
Logged
Gary Dickens
Gold Member
*****

Kudos: 14
Offline Offline

United Kingdom United Kingdom

Posts: 425



Ignore
« Reply #81 on: April 11, 2022, 03:30:05 PM »

Thanks for that. Shame I sold my box of May '99 tan II !

Gary
Logged
Indoorflyer
Platinum Member
******

Kudos: 30
Offline Offline

United States United States

Posts: 1,579



Ignore
« Reply #82 on: April 11, 2022, 05:49:56 PM »

Is the span limit (e) also a flat "plan" dimension?
Logged

If you believe "There is no such thing as a stupid question", you probably don't have a Facebook account
Edgeworm
Bronze Member
***

Kudos: 3
Offline Offline

United Kingdom United Kingdom

Posts: 12



Ignore
« Reply #83 on: April 13, 2022, 01:44:40 PM »

Based upon the definition of the wing, I would assume so, but I can't give a definite answer. Perhaps there are more informed experts about, particularly in the States. I don't think there is any need to push things with loop holes in the rules, the stabiliser area seems very generous to me. Looking at earlier designs such as the UK's 'Tallboy' from 1978, it looks like the permissible tail area might have been enlarged over the years.

Looking at the photos of my model a few posts up, I used the dihedral fins to get a little more tail area for my Legal Eagle design. For the Manhattan, I made sure the tips of the fins were within 12 ins span limit just in case it was the projected span of the whole stabiliser assembly.

Edgeworm
Logged
piecost
Gold Member
*****

Kudos: 14
Offline Offline

United Kingdom United Kingdom

Posts: 677



Ignore
« Reply #84 on: April 13, 2022, 03:06:48 PM »

Edgeworm,

Can you recommend a rubber motor size?

Logged
ChrisH
Bronze Member
***

Kudos: 2
Offline Offline

United Kingdom United Kingdom

Posts: 82



Ignore
« Reply #85 on: April 14, 2022, 12:42:21 PM »


(d) An unbraced monoplane wing is required, mounted directly on the fuselage (no pylons or wing posts), maximum size 20 ins x 4 ins flat (not projected).

(f) Tissue or condenser paper covering is allowed, but plastic films are not.

(g) Minimum weight without rubber 6 grams.



Can I ask why BMFA made some rule choices?

d)   Why were pylons and wing posts not allowed in UK?

f)    Isn't there difficulty sourcing lightweight condenser paper?   Lou Gitlow used to sell light condenser of 5gm/m^2, but I haven't been able to find anything below about 8gm/m^2 in UK.   Its still much lighter than Jap tissue at around 12 gm/m^2, and isn't porous.    However, if the minimum weight has been lifted to 6gm in UK, does there really need to be a ban on plastic film covering?


I have used cheap 2.4 gm/m^2 mylar from Mike Woodhouse on 2 gm Saint models.   The mylar could be shrunk on the fuselage after covering, using a soldering iron, with a sheet of writing paper between the model and the iron, adding some stiffness to the fuselage.
Logged
DavidJP
Titanium Member
*******

Kudos: 47
Offline Offline

United Kingdom United Kingdom

Posts: 3,257




Ignore
« Reply #86 on: April 15, 2022, 12:43:01 PM »

I am happy with those rules - a minimum weight of 6 grams is fine - much better than maximum weight of 6gm!  Smiley   Quite happy with tissue covering.  Don’t rate film save for underneath tissue.  Quite like wooden props. as making them is theraputic.
Logged
Edgeworm
Bronze Member
***

Kudos: 3
Offline Offline

United Kingdom United Kingdom

Posts: 12



Ignore
« Reply #87 on: April 27, 2022, 01:47:09 PM »

Hi Guys,

I've been busy at work for a few weeks so haven't checked in on this thread. To mop-up some queries in recent posts:

Prop diameter seems to be about 12ins for Manhattan and that works for me. At this prop size, I'm using 2 strands of 0.105 ins to 0.110 ins at 19 to 20 ins long for low ceiling sites.

I don't know why wing posts were banned. I guess the look of the model should be like a bit like a vintage Wakefield, so this may be why the wing has to be banded onto the top of the box fuselage. Although a duration contest, the look of the model also seems to have been important (although not scored) in the class' heyday. I have seen American designs with the wing supported on four short wing posts above the fuselage. Theoretically, this should generate more lift as the central wing section is working; although probably not very efficiently.

Supply of condenser tissue is not a problem, it is available mail order from Free Flight Supplies. Mike has stock, by chance I checked today. This was the stuff I used to build my Manhattan and it's just over the 6 gram mark. I think the issue with plastic film is its transparency. As stated above, the model should look like a vintage rubber model with a real presence in the air and so I guess clear plastic film was deemed to go against this. Those are the rules anyway at present; I was just pondering a possible solution if condenser became completely unavailable.

Cheers,

Edgeworm
Logged
ChrisH
Bronze Member
***

Kudos: 2
Offline Offline

United Kingdom United Kingdom

Posts: 82



Ignore
« Reply #88 on: May 03, 2022, 09:24:14 AM »

I looked for condenser paper offered by Mike Woodhouse too.   I cannot find anything lighter than 7.8 gm/m^2 today, and haven't seen anyone offering lighter paper for years.   I assumed the scarcity of light condenser paper was the reason AMA have amended their Manhattan rules to allow plastic films to be used.

The covering area of a Manhattan Cabin is approximately 250 square inches, so the covering weight alone can quickly become a significant chunk of the model weight.

12 gm/m^2 Jap tissue would give 12 x 250/1550 gm = 1.935 gm
  7.8 gm/m^2 Woodhouse condenser                        = 1.258 gm
  6.0 gm/m^2 condenser                                         = 0.968 gm
  5.0 gm/m^2 Lou Gitlow condenser                         = 0.806 gm
  2.4 gm/m^2 mylar                                                = 0.387 gm

Perhaps this explains why Ray Harlan describes ballasting his Mylar covered Manhattan UP to the American 4gm minimum weight, with slivers of solder glued under the CG!

Isn't there a danger of killing what could be an exciting return of Manhattan Cabin if it needs unobtainium to build it?   It is hard enough to find Ambroid, wood and Tan 2, without adding to the list.

BMFA becomes the British Material Finders Association.

At least the proposed/old BMFA Manhattan rules don't stipulate a maximum window area covered in transparent material!
Logged
piecost
Gold Member
*****

Kudos: 14
Offline Offline

United Kingdom United Kingdom

Posts: 677



Ignore
« Reply #89 on: May 07, 2022, 12:44:57 PM »

Some good data there Chris. I will have to check my Sam's condenser tissue.

Edgeworm's model would make a good plan (hint, hint)
Attached files Thumbnail(s):
Re: Is Manhattan Cabin even flown any more?
Re: Is Manhattan Cabin even flown any more?
Logged
Greg Langelius
Gold Member
*****

Kudos: 24
Offline Offline

United States United States

Posts: 668




Ignore
« Reply #90 on: May 08, 2022, 12:27:12 PM »

I must differ with the rule changes.

I was flying Manhattan Cabin in the late 80's, early 90's right up until Columbia University banned outsiders from using their facilities (Low Rotunda, etc.) for non curricular activities.

I thought we were dead in the water until I saw a modicum of evidence that the event was still active. This pleased me greatly.

Now I see that the rules have been altered to an extent that the model has different dimensions, features, and explanations for said alterations.

Folks, what you've invented (Reinvented) is another aircraft and another event; and it does not rate the name "Manhattan Cabin".

Call it anything you want, but please don't call it Manhattan cabin. It is not Manhattan Cabin. Manhattan Cabin was and ought to remain as described in Ron's book, and conform in dimensions and features to those model aircraft which were flown beneath the rotunda's Dome.

I recently asked for an alteration to an event on these pages and got (essentially) cut off at the ankles. I think this set of circumstances deserves a little bit of sauce for the Gander.

I would ask that any who changed the Manhattan Cabin Rules please explain their justifications for those changes.

With deep respect;

Greg Langelius.
« Last Edit: May 08, 2022, 12:37:43 PM by Greg Langelius » Logged

New knowledge is found by re-examining old assumptions.
Indoorflyer
Platinum Member
******

Kudos: 30
Offline Offline

United States United States

Posts: 1,579



Ignore
« Reply #91 on: May 10, 2022, 05:50:03 PM »

I must differ with the rule changes.

Now I see that the rules have been altered to an extent that the model has different dimensions, features, and explanations for said alterations.

Greg Langelius.

In the USA, we need not be concerned about the BMFA (UK) rules.  As far as the current AMA rules ----  An older design with the smaller stab is still "legal"--the current requirements are stated as MAX projected dimensions. There is nothing in the AMA rules dictating use/non use of wingposts.  Also, wood bracing (stab and wing) MAY be used if desired; again not required.  Either paper or plastic film covering is allowed.
Logged

If you believe "There is no such thing as a stupid question", you probably don't have a Facebook account
Greg Langelius
Gold Member
*****

Kudos: 24
Offline Offline

United States United States

Posts: 668




Ignore
« Reply #92 on: May 12, 2022, 11:49:50 AM »

Good points, all; but they don't explain why the BMFA Rules had to be different. There may be value in those reasons, and I'd like to understand the reasoning of how they came about.

Greg
Logged

New knowledge is found by re-examining old assumptions.
Gary Dickens
Gold Member
*****

Kudos: 14
Offline Offline

United Kingdom United Kingdom

Posts: 425



Ignore
« Reply #93 on: May 12, 2022, 04:11:15 PM »

Does it matter? Your previous comment suggests you are very unhappy about the rule changes in the U.K.
If you're never going to fly there, what difference does it make to you what version of the rules they use or what they choose to call it?
The rules in the U.K. would have been tweaked for reasons probably known only to the rule makers themselves and hopefully to accommodate the handful of people who flew the class.
Logged
Edgeworm
Bronze Member
***

Kudos: 3
Offline Offline

United Kingdom United Kingdom

Posts: 12



Ignore
« Reply #94 on: July 27, 2022, 01:51:02 PM »

Hi Guys,

I had a talk with Bob Bailey at the TVAC meeting on Sunday. He is one of the few people around who was involved in indoor free flight performance in the 1970s when the UK Manhattan rules were drafted. Apparently the idea was (as ever) to attract outdoor flyers who might have built some of the myriad of box fuselage rubber models into indoor free flight performance. Bob said the rules were modified to make the class easier to build with UK-available shop wood and materials (at the time). According to Bob, there was some success with this, with some models being build, but it wasn't very popular.

I would also just like to remind everyone that the Manhattan class is not currently in the BMFA rules book because of a perceived lack of interest. So therefore no official Manhattan contest can take place. The rules I quoted above were taken from the last rule book before they were removed (about 2013 I think). So there really is nothing to complain about...

Meredith
Logged
Greg Langelius
Gold Member
*****

Kudos: 24
Offline Offline

United States United States

Posts: 668




Ignore
« Reply #95 on: July 29, 2022, 10:18:24 AM »

...And therefore, I retire my complaint. I also apologize for being on the outside, looking in. Apparently such a position disqualifies me from receiving a direct answer.

I mostly appreciate the effort to provide a direct response, instead of dodging with an old ad hominem two-step.

Greg
Logged

New knowledge is found by re-examining old assumptions.
Edgeworm
Bronze Member
***

Kudos: 3
Offline Offline

United Kingdom United Kingdom

Posts: 12



Ignore
« Reply #96 on: August 03, 2022, 02:31:38 PM »

Hi Greg,

I'm rather new to the forum so as I was unfamiliar with the 'culture', I was at pains to keep my replies on this subject addressed to the general audience, rather than as a direct reply to you, in order to avoid any potential misconception that they might be too 'personal' for this forum. I respect and support the rules governing this forum and find them a refreshing change from other forms of social media.

I'm glad we've got things resolved.

All the best

Meredith
Logged
Greg Langelius
Gold Member
*****

Kudos: 24
Offline Offline

United States United States

Posts: 668




Ignore
« Reply #97 on: August 07, 2022, 12:53:51 PM »

Ditto.
Logged

New knowledge is found by re-examining old assumptions.
Pages: 1 2 3 [4]   Go Up
Print
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.21 | SMF © 2015, Simple Machines Valid XHTML 1.0! Valid CSS!