TerryE

My Feedback: (12)

George;

Just got the Ultimate 3D Biplane kit in the mail today

In reading the threads, I notice that there seems to be more weight needed "up top".

I was thinking of using 1 standard size servo (Futaba s3003) for the ailerons, and mounting it in the top wing, then I wouldn't need a Y harness, etc.

What do you think??

GRH

I'm not familiar with the Futaba servo's overall torque but I'm sure it would be enough to drive all four ailerons...you probably could get away with a 15-17 in-oz servo. Either way make sure your servos weighs about 0.5-0.6 oz max. The real problem will be actuating the ailerons without incurring a lot of differential The ailerons are several inches apart which would require a very large servo arm to push perpendicular to the hingeline...if you push at an angle you will get differential deflection which you'd like to avoid. Running two ailerons into two separate channels allows you the adjustment necessary to get the differential that flies best.

George

TerryE

My Feedback: (12)

Well. I'll be a son of a gun [X(]

I have never heard a cohesive answer as to why you would use 1 vs 2 servos... until now

Thanks a lot, that makes a lot of sense. I will go with the two servo setup.

Would you recommend that I put both of them on the top wing, or on the bottom?

Thanks

GRH

One thing I forgot to mention is that the aft aileron hingeline sweep will make it even harder to run one servo. Some other benefits are that, if you want to, you can also mix elevator into the ailerons so you can have a spoiler or flap effect.

I prefer to put the aileron servos under the upper wing to get the vertical CG higher so it will be more inline with the thrustline.

George