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I am currently trying to trim my Lanier Pitts (see avatar) and I am having problems with my positive snap rolls. It seems that on high and low rates the Pitts barrells and changes heading quite a bit. This does not occur with a negative snap as they are wicked fast.
My throws at low rates are about 20 degrees on elevator and rudder, ailerons need all I've got to get a decent roll rate (wish I made them a few bays larger).
Any hints tips or tricks?
Thanks
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Warren

My Feedback: (72)

Try "unloading" the snap: As soon as she starts to go, reduce elevator (some can go neutral after rotation starts) to keep the energy up.

Let us know if that helps; worked wonders on an old Byron Pitts I once to have.

krayzc-RCU

My Feedback: (31)

try 10 degress for the elevator and rudder and 25 degress for the ailerons and see how that does that should clean you right up

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My Feedback: (18)

Thanks guys.
Went out today and tried some variations with elevator throws and it seems 0 degrees to about 5 degrees is all it needs, unloading in the snap also helps.
This plane may take a while to set up it has been a real pain in the #$$ since the first flight..
Love the spins though..
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Blow n Go

Yep, you gotta love bipes to put up with them! It takes about 40 or 50 flights to get the radio mixes and throws right. The monowing guys never understand what we go through. Your pits will draw a bigger crowd than a dozen mono's, though.
It sounds like your on the right track so far. When I tune a new plane, I go through the following order:
First, get the CG as far aft as you can stand it. Check it by rolling inverted and checking how much forward stick it takes to hold level inverted flight. A little is good. A lot is bad. None makes the plane tricky to fly and impossible to land. Keep moving it aft until the plane will not fly a decent line in level flight and the landings get tricky. From that point move it back forward until your level lines are decent.....landings may still take a little work.
Next, check your lateral balance. If the plane is trimmed hands off when right side up, it should not roll when inverted. Add a little wingtip weight till there is no roll either way.
Now you are ready for setting your throws. 3D rates are as much elevator and rudder as you can get......Usually close to 45 degrees on most planes. Ailerons are around 40 degrees. We'll call these rates "full throw." You'll need lots of expo for these rates. Sport rates will be around 1/3 throw for the rudder, half throw for the ailerons, and just enough elevator to stall the plane in level flight with the engine at idle. The idea is to make the plane fun to fly on sport rates. Set them wherever you feel best in the landing pattern and generally "beating up" the sky.
Pattern rates are the most difficult to set. Reduce the elevator gradually each flight until the plane will not snap, or full stick deflection makes a decent size loop. Increase just slightly above this rate and you've got it. (Mine is about 18% of full throw.) Rudder is just enough to hold level knife edge flight at half throttle. (Again, mine is about 22% of full throw.) Ailerons are reduced so that full deflection gives you a decent roll rate for all pattern rolls. This will be less than sport by at least a little. ( Mine are 25% of full throw). Pattern rates are uncomfortably slow in most situations, but they make your maneuvers very smooth when you're being judged
Now I set my rudder to elevator and rudder to aileron mixes. Thats a real pain that I won't bore you with.
For my ultimate, I have to go to 3D rate aileron to snap. The rudder and elevator can be at pattern or sport. Your pits may snap on low rate aileron, which is a good thing. Remember that the aircraft behaves differently when snapping power high or low, too.
Keep us informed on your progress!

CJ

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My Feedback: (18)

CJ,
Thanks for all the info. I have about 8 full flights, that count anyway, on this bipe so far and slowly becoming more comfortable. I am still balancing laterally but the cg is about where you describe on yours. The plane doesn't float but its not a bear on landings either. The elevator is still a tad to much for sport flying. As for the ailerons they are set with a good pattern roll rate for the lows and unfortunately thats 80%. I should have looked closer at the size when I built the thing and lengthened them.
For 3-d I don't think it will fly well. I have a played with it in a harrier position and it is a hand full on wing rock. It will do a nice tight loop (outside waterfall size) when pulling out of a inverted flat spin to an attempted torque roll (I am new at 3-d flying) but will not do a waterfall from torque roll or harrier or slow flight.
Spins well name them it does them, knife edge seem to be the best. The flats are very loose so I am attempting to tighten them up.
I haven't started with mixing (never liked to in the past) yet but will, and the expo is definitely going to take time as will differential.
Thanks again
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krayzc-RCU

My Feedback: (31)

i agress bipes draw the crowd i hope to have my ultimate up in the coming weeks pics below:

http://members.cox.net/krayzc/

v-snap

My Feedback: (18)

Snaps came right along now with about 10 flights. But right on schedule something else let loos on the frame. The caban strut foward mout decided to break in flight. Vibration caused abreak right at the bend.
Could have been worse though, the plane landed without difficulty. It was fun watching the pitch changes though when you used elevator.
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