RTang

Hello all!

Im finishing off a 56 inch Sukhoi 26mx that i have built, and have used a design for the aileron servos so that they are mounted inside the wing and on a removable ply plate.

So the problem is that there will not be enough clearance if i used one of the servo arms, apart from the one that i used previously on a throttle control. This arm is much longer than the others and would clear and allow so that there is no binding with the wing and the control rod.

Is it a good idea to use those servo arms that have just one side and are adjustable in length? It has two parts and have fine teeth that stop it from moving. They are plastic and were found from the hardware of the hitec HS-422 servo, which is to be used as well. The second piece (the arm) is clamped down on to the servo output shaft by a screw.

Does any one else use these types of arms for big load surfaces?

The plane has fairly large ailerons (one servo per each) and expected dry weight of the plane is 84 oz (5.25 lb).

Thanks in advance.

pettit

My Feedback: (23)

Those "extendable" servo arms are especially made for throttle linkages. They may fail with any higher load placed on them.

DuBro makes longer servo arms for all brands of servos. Ask your LHS to get them for your servos.

I use them all the time.

ksechler

Right! I recently read a post in the section for crashes about someone using one of those on the elevator. Don't use them on any flying surfaces.

TexasAirBoss

My Feedback: (22)

Additionally, the longer the arm, the more the slop in the servo output will be amplified !

RTang

Thanks so much for the insight and info.

I would not want to lose my plane for some faulty control linkage.

I will look for some other slightly longer arms to provide that clearance needed.

Thanks again.

pettit

My Feedback: (23)

follow this link to the DuBro catalog for servo arms that will work.


http://dubro.com/DUBRO2005CATALOG/im...talog_5CB9.jpg

I hope you can get this stuff down where you are...

RTang

Thanks for the link!

I will search around for them, or find alternatives in the hobby shops around here.