FrancisPerson

I am building a Sig 4*40, so far so good. Look at the copy of the plans. The book says that if you build it per the plans you will have aileron differential where the aileron will deflect up more that down. In my experience if the torque rods are as shown the differential will be wrong (more down that up).

Am I crazy? Did you have correct aileron deflection on your 4*40???


Francis

jrbmoto

Well.. I had to pull my 4* wing off the shelf to investigate because I agree with you that it looks as though the suggested setup would give you more down than up....however, after twisting the servo back and fourth a couple times, indeed I am getting more up than down...I can't explain why but I suspect that it has something to do with the fact that the pivit point where the clevice meets the torque rod (actually the nylon eye that screws on to the torque rod) is ahead of the hinge line. Also consider that the servo position in relation to the torque rod could effect the geometry : If the servo output shaft is't 90 deg. to the torque rod, you will get some differential....whatever...obviously our friends at Sig have done all the r&d so my advice is build it like they want you to and I'm sure it will be fine...I've built several 4*s over the years and always used the single aileron servo setup acording to the plans with grea success!

Johnny

TubaTom99

My Feedback: (3)

Whew. I thought I was going crazy. Although, I assumed I could have compensated with different types of servo control arms.

Tom

FrancisPerson

With sweaty palms and a furroughed brow I will build as directed.



Thanks

Francis

MinnFlyer

My Feedback: (4)

It looks backward because you're thinking of it backward. IF that were a servo arm, it would send more down than up, but it's on the other end of the pushrod, so you get the opposite effect.