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Need info on Servo/spring bias aileron trim

F

fabricflyer

Well Known Member
Has anyone bought the EA-7/9-kit (Servo and spring bias assembly) for aileron trim? I need to know what is in the kit (Servo Type & model) and plans for installing it. I have the manual spring trim now and thinking about upgrading. Would appreciate any info.
Allen
 
Hi Allen. I am also planning to add servo to my manual RV7 aileron trim. I ditched the springs and links in favor of bungee cord with electrical eye end crimped at each end and connected at same places. It is much smoother, quieter and if it ever broke, is unlikely to jam controls. Now I just need to find the best place to mount the servo so I am also interested in original plans.
Can someone scan the aileron servo plans doc for us?

My bungee system prompted me to consider the same for the rudder, I have put a small yachting pulley on the firewall at the forward corners of copilot side rudder pedal, and put a bungee connecting both rudder pedals through the pulleys in the corners. This keeps the rudder cables reasonably tight at all times. If I fit a servo at the mid point of the bungee between the rudder pedals, I will be able to bias the rudder and provide adjustable rudder trim.
Anyone tried this?
Regards Morris.
 
I had the manual trim. As I need the aileron trim now and then I didn?t like to grab down between the seats to make adjustments, especially with a passenger. So I converted it to the electric system. The electrical kit is slightly different and the control arm below the seat panels is mounted offset compared to the manual system. It is designed without a hole in the floorboard where the handle goes on.
So I left the manual system where it was and mounted the servo slanted towards the actuation handle to adjust the thrustline of the servo. On top of the floorboards I mounted a small metal pointer which serves as the trim indicator, so I didn?t use the electronic position indication provided by the servo. Hope this helps.
 
morristull said:
Hi Allen. I am also planning to add servo to my manual RV7 aileron trim. I ditched the springs and links in favor of bungee cord with electrical eye end crimped at each end and connected at same places. It is much smoother, quieter and if it ever broke, is unlikely to jam controls. Now I just need to find the best place to mount the servo so I am also interested in original plans.
Can someone scan the aileron servo plans doc for us?

My bungee system prompted me to consider the same for the rudder, I have put a small yachting pulley on the firewall at the forward corners of copilot side rudder pedal, and put a bungee connecting both rudder pedals through the pulleys in the corners. This keeps the rudder cables reasonably tight at all times. If I fit a servo at the mid point of the bungee between the rudder pedals, I will be able to bias the rudder and provide adjustable rudder trim.
Anyone tried this?
Regards Morris.
Click to expand...

Been there, done that, didn't work. Your legs have the strongest muscles in your body. A spring based rudder trim needs heavy duty springs and a large servo... Almost like a flap actuator. A trim tab is much better.

Some folks use a stong bungee cord attached to the right side rudder cable and hook it into a series of holes or slots as a primitive trim system.

I think that a friction clutch might work well. Center the ball and engage the clutch lever. If you move pedals, the clutch will release, otherwise it will hold the rudder position.

Maybe the ASA guys can make one up.
 
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