Yellow Aircraft P-40
 

Hey all-

I have a couple questions about the Yellow Aircraft P-40 giant scale.

Mine is used, but I am unable to locate specs on control surface throws and center of gravity. Anyone have this information?

Also looking for a set of Main Gear Doors. https://cimg5.ibsrv.net/gimg/www.rcu...a0232704d1.jpg


Thank you!

Didn't YA go out of business?

Yes they did!

OK, since the experts seem to be ignoring this. I'll offer my 2 cents worth.

There's a couple of things I would do. The first is research the control throws of the real thing. They will be in degrees from neutral. A museum would be my choice for doing that. Either the AF museum in Dayton, OH or the one in Kalamazoo, MI at the airport. I know they have a p-40.

Another thing you can do is contact the manufacturer of any warbird of similar size and ask what the throws on their kit are. I know Meister Scale has several in your range.

Last but not least and based solely on my experience. I'd start with the Ailerons doing 25 deg up and 20 deg low rate. Rudder at 30 deg left/right and low rate at 20. Elevator at 30 deg and 20 low rate. First take off I'd go low rate on the elevator.

For other reference, my Cherokee uses 15 deg elevator and flies just fine at that. And that is also what the real one uses. The rest of the controls are set to the full size spec too. So I would lean towards option one.

Last but not least, the sailboat crowd have done extensive studies on rudder deflection. And they have found the efficiency of the rudder falls off considerably above 30 degrees. IOW, anything over 30 is pretty much a waste. Except flaps of course or some specialty plane.

Let us know what you figure out and do.

And while I think of it, you could download a set of free plans from Outerzone.

I know Dave Platts Top Flight P-40 from the 60's is in there and has all the throws, CG etc. You'll have to do some conversion from the 60 inch Platt model to your 89 inch. But it's doable and will get you in the ball park.

Word of caution, the landing gear moves the CG to the rear when retracted. So set your CG with wheels up.

Perhaps you could use this as a reference or a starting point.
Attachment 2263437

I found this on page 35 of that manual, which is for an 86" span Warhawk, so these should be close to what your 89" spanned bird would need:
These are the recommended control surface throws:
RATE................... HIGH............................ LOW
Elevator................ 1"/13*.......................... 3/4"/10*
Rudder............... 1-7/8"/18*........................ 1"/9*
Ailerons............... 1"/18*.......................... 3/4"/13*
Flaps................ 2-1/2" /36*
All of the above is measured at the widest part of the control surface
It also says to balance the plane 5.5" back from the leading edge of the wing when using the GP C.G Machine. The manual gives an experimentation range of 5/16 forward to 3/8" aft as well, depending on the pilot's skill level

5.5 inches back from the TRAILING EDGE???? Am I missing something here?

Nope, typo on my part that I fixed when you called it out
Thanks

It's what the manual said, I just copied it, less the metric figures that weren't really needed

I appreciate all the input very much! thank you all

I know this is an older thread, but I am just putting the last touches on my 3rd Yellow Aircraft P-40. I thought I would add the asked for information from the Yellow P-40 manual just in case someone is looking for it in the future.
Center of Gravity is 4 inches fron the leading edge at the root with gear retracted.
Aileron 7/8 inch each way
Elevator 5/8 inch each way
Rudder 2 - 2 1/2 inch each way
Flap 45 degrees
good luck on any future builds.
https://cimg3.ibsrv.net/gimg/www.rcu...16c544c970.jpg

I've seen too many P-40's and AT6 Texans go in because of too much elevator throw....beware.

YA. P-40. CoG
 

Can anyone double verify the CG is 4” from LE at the root with gear retracted and plane upside down ??