I just purchased a Midwest AT-6 Texan with a Saito 1.20 and Robart retract system. The plane has never flew and the engine never fueled. I consider this a lucky find since it's very detailed with full scale features. My question(s): What is the balance point for this aircraft and where do I measure from....Front of wing leading edge or front of wheel well? The gentleman I bought this from loaded the nose with lead apparently to make it balance but I must be sure he was acurate. Also, what weight should this plane be at for normal scale flight? And finally....how many pounds of air should I pump int the two cans in the retract system? I tried at 80 lbs. and the system worked fine..but for how long? Should I pump more?
For those of you who have this plane and care to help me out....many, many thanks.

What is the total weight of the plane? I test flew one for a friend in the club that weighed 18lbs and flew with a saito 180. It had enough power but all the weight was glued into the cowl. Real bad idea, the cowl kept breaking off the mounts. With a saito 120 it should be under 14lbs at the very most. It lands pretty hot without flaps. I dont know where the cg is right off the top of my head but I can tell you that every AT-6 I've seen balanced measured from the forward section of the wheel wells. Make absolute sure what the correct way is cause it wont last long if its tail heavy. Use a real light touch on the elevator, you dont need a lot of throw. Otherwise it will snap if too much is used in a loop and go into a spin. Be up real high when you try that, it takes a little bit to stop the spin. Like most warbirds you want a fair amount of rudder and I dont really know how to tell you how much aileron. I call it an average amount, some have said its not enough. Best to setup with expo and dual rates until you get a feel for its character. My takeoffs were pretty smooth, the landings were like a ton of bricks looking for a place to drop. Keep on the throttle cause it stalled abruptly. Not fun at all. Would have been better if he had built it with flaps. I normally use around 100psi in my airtanks. I've been known to go as high as 120, but no higher than that. 80psi will work, I just like to have 4 or 5 cycles just in case.
Edwin

Thanks Edwin, this is very helpful information. I now wonder what I've gotten myself into. My plane weighs about 9 lb. dry so maybe it won't need alot of speed to fly. My plane also came with a computer radio set up with alot of travel in the elevator. Going to change that.
The reason I ask about the balance point is because the owners manual tells how to build the plane but has no specific numbers for balancing, only a diagram. It seems like guess work. This seems to spell danger if you're experimenting with a tail heavy plane to find the right balance point.

Mine weighs about 14lbs with an A&M 2.0 gasser. I think the 1.20 will be borderline power, unless you are really light. Mine needed 1lb of weight on the firewall, and balances 6 1/4" back from the front of the wheel well. The plans show the balance point at the point where the wheel well cover meets the sheeting, (6 1/4"). I don't have flaps and the landings are hot to say the least, but the model is very good flyer. I usually use about 100-110# of air.

Since a couple of people have them at 14 and 18 lbs it seems unreasonable to me that one could come in at 9 lbs.
Hopefully your weight is accurate and the plane is well built, with that kind of wing loading yours should be an excellent flier.

I made a misleading mistake here....I did not proof read what I wrote and I should have. I left a 1 out of my sentence. That's a 19 pound plane not 9! It would make a nice glider at 9 #. Sorry about that. Anyway, I think Terry is probably right about Saito 1.20 being borderline to fly this plane. It may take a couple of football fields to take off. Now the sad part: I think I may have bought an underpowered / overbuilt AT-6 Texan and I will have to dig into my pockets for some $$$ for a bigger engine.[>:]
Would a Zen G23 turning a 16 x 8 work better? More weight than Saito. I have one here looking for a home.

Wow! 19lb? Mine is a tad under 15 with the Robart 620s and a Webra 1.20 with Bisson muffler. I think you'll be disappointed with the Saito, but that's just my opinion. I bought mine in a similar situation, fully built, never been fueled. It does have flaps though, which is the way I intended to build the kit myself. I've been tinkering with it off and on since March and finally got it up in the air this past weekend. It was an E-ticket ride, lasted all of about 20 seconds before the impact. Luckily, I only bent one of the mains (fixed), broke a bit off the wingtip (fixed), ripped the vertical stab and rudder clean off (not fixed, but easy), and busted one of the ailerons (not fixed, will be soon). I thought I remembered checking and double checking the CG per the plans, but it flew like it was way tail heavy. So I'm going have to move the CG before my next attempt.

I've got a copy of the manual with the recommend control throws. I'll try to remember to post them here for your enjoyment.

At 19lbs, I would consider a G-38, or similar. The one I have was originally flown, by the previous owner, with a G-38, and it balanced perfectly without any ballast.

I checked the plans tonight, the C.G. location is between 3-7/8 & 4-7/8 from the LEADING EDGE of the wing, not the wheel wells.

Control surface throws are spec'd as follows-

Ailerons - 7/8" up and 1/2" down
Elevator - 3/4" up/down
Rudder - 7/8" up/down

3/4 on the elevator doesn't sound like much, but it was way plenty in a tail heavy (I suspect) condition with mine. I just finished building the busted aileron back up, plan to sand and cover it tomorrow. She'll be ready for another go Saturday morning.

-Greg

Here is a couple of pics of the plans showing CG. 1st pic shows from front of wheel well, and 2nd, from L/E.

Yes. That's what I was considering after some more thought, a G38, and I happen to have one. I definately need more power than what I have for fear of stalling somewhere. The man I bought it from never flew this bird nor did he ever have a model like it. Looking at the plane, you wouldn't think it was that heavy. But man oh, man..it is!! Just look at the photo and see all the weight bolted on to the nose. Enough weight to make it balance, but plane will lack power. Even so, if I bolt a G38 on and it's slightly nose heavy....that's better than tail heavy, yes?

Thanks, Terry. The balance point photos will be very helpful when I start working on this.

FYI --- I unloaded all that lead and unbolted the engine then weighed it all together. It came up to 6 lbs. even. My G38 weighs just over 5 1/2 lbs.. This is an easy decision to make. Thanks everyone for your help -- see you at the field!!