Changing Moment Lengths

Ok, Let me see if I can get this idea across.
A customer of mine has decided to kit bash a Brodak Zero into the predisessor of the Zero, The "Claude". In order to do this the nose has to be cut back about 2 1/2 to 3 inches to give at least a close look of the original plane. Now, realizing that the Brodak kit is just a stand off lookalike and is actually stretched a bit, does my friend have to decrease the tail moment as well to keep the new plane from looking way too stretched?
At first drawing the new profile body will be about 33" total. The kit Zero is nearly 36" long. He plans on using an OS LA .40 with the Sullivan 4oz tank inboard.
Any Ideas?
Joe

Joe:

I would wager that loppong a couple inches off the nose will make the thing work real well....leave the tail moment where it is...

We have a good flying Zero around here....with fixed flaps....seems to work fine, too.

See Ya

Leaving the tail moment as is leaves the "Claude" looking way too stretched out! The original plane was very tiny and compact. Perhaps some compromise is in order.What say?
Joe

not familiar with th airplane....but it sounds like u may wind up with balance problems.... mite get tail heavy on ya .... i revamped (lopped of th nose)a flite streak once....cause they are so nose heavy.... turned it into a hunter ... so if it turns out this way ...add nose wieght ...lots of it .... jim

Get a sideview of each plane. Scan 'em into the computer and then start blowing 'em up and reducing them down in a drawing program to see what they look like comparatively. Usually you can get a pretty decent looking stunter by making the fuse 1:1 scale, the wing 1.25:1 or so, and the tail 25% of the wing.

Odds are the Brodak kit has a way short tail moment for a Zero, so shortening the nose may make it closer to a true scale Claude.

More to the point, taking 2.5 in. off the nose will make the plane godawful tail heavy, unless you put in a big engine. Tiger 51 with the stock muffler maybe??

LAST EDITED ON Nov-13-04 AT 08:25 PM (CST)
 
I was thinkin' K&B .40 #4055 "Brodak Stunt" version. Almost impossible for anything to come out tailheavy with that hunk on the nose. Steve

Edit: On second thought, I think it would be incredibly cool to bash a Zero kit into an AT-6 wannabe...the reverse of the way they did it in the movies, you see. Or, you might get really obscure, and turn it into an AT-6, then change that into a Boomarang (I think that's right)...the Aussie version of the Texan/Harvard, modified into a single seat fighter early in WWII. Unfortunately, the Aussie insignia with the "red hopper" in the middle didn't come in until after the war. On second thought, I think the fighter was the "Wirraway".

Edit2: Did some actual research, found it was a 2 seat fighter, and was known both as the "Wirraway" and "Boomarang", for some reason. Built under license from North American by Commonwealth Aircraft Corp. Power was a CAC-built 600-hp Pratt & Whitney R-1340-47 Wasp radial. I bet it was more fun than a AT-6. The extra 50 hp might not have made that much difference, but the three machine guns would be a lot better than none.

LAST EDITED ON Nov-13-04 AT 08:05 PM (CST)
 
>
>
>Odds are the Brodak kit has a way short tail moment for a
>Zero, so shortening the nose may make it closer to a true
>scale Claude.

Phil, the Brodak tail moment is 13 1/2" and looks way too long as you look at the drawings on the Brodak plan sheet. The nose is way too long also, and the Claude is a much more compact version. We are still working on the conversion and it looks like the finished product will be about 33+ inches in body length as compared to nearly 36" on the stock kit. FUN!
Joe

LAST EDITED ON Nov-13-04 AT 11:08 PM (CST)
 
>More to the point, taking 2.5 in. off the nose will make the plane godawful tail heavy, unless you put in a big engine. Tiger 51 with the stock muffler maybe??

Phil C
My Brodak Zero, built to plan needed 1 oz tail weight for it's best performance with an unmuffled OS35S(7 oz approx). The LA 40 is maybe 2 oz heavier, plus muffler, still 2" or more shorter nose moment is a lot. I would think shortening the tail moment about 1" should make the CG about right.
BTW, the Zero at 38 oz was the best flying of all the 48" span warbirds I have built. Probably nothing special in the design as all the series are so similar. Maybe it just all came together correctly in this particular model's construction and trimming.

>Phil, the Brodak tail moment is 13 1/2" and looks way too long as you look at the drawings on
>the Brodak plan sheet. The nose is way too long also,...

Why not scale up the fuselage vertical dimension. Wouldn't that make it more scale like without shortening both nose and tail?

SK