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Trim forces with aileron trim

JDA_BTR

Well Known Member
I'm putting the trim aileron system together, and it is all fitting together fine, except that the little slot to hold the wire connector makes no sense and I'm not using that cutout.

My question is about the spring tension and how the forces work for trim. The way it is setup any aileron action at the stick must pull on the trim actuator arm via the springs connected to it. The springs are pretty strong - 6" of spread when connected and seems like 30-40 pounds of force to get it done. The springs counter each other so tensioning one relaxes the other, so I suppose at the stick you can't feel the difference when moving it around?

The linkages to the spring arm move freely but there is a little play at the elbow so that the arm has about 1/32 play. Will that make any practical difference? Or should I redo the linkage between the servo and spring arm to get that play out?
 
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I'm having trouble following your question. Your are referring to the actuator arm , do you mean on the servo? You can feel the spring tension static but I do not notice them in flight.
 
There is the arm that comes out of the servo. then a linkage to the rotating arm that connects to the spring. The rotating arm has a little lateral play, not much. The linkage at the servo arm is tight. The linkage to the rotating arm has more play. Overall it is 1/32 at the end of the linkage arm back and forth; just a little wiggle.
 
I think your good to go

I have the aileron trim installed. I don?t think the little bit of wiggle is going to effect much. The whole linkage assembly is put together with pins. I?m pretty sure my arm has a little bit of wiggle without the spring tension on it as well. The spring tension takes up the wiggle. In the end, due to the wiggle theoretically you end up with about 1/32nd of deadband when switching directions. The aileron trim isn?t sensitive enough to notice it. You could confirm with Vans, but I would build on.
 
I?ve installed the module in the wing. When the aileron is deflected I?m seeing a fair amount of flex in the access plate - those springs are really strong and it was some work to get them both on. When I move the aileron through the neutral position there is a slight rattle sound as the linkage jiggles passing thru the neutral position. I?m tempted to take it off and remake the linkages for zero play but not sure if that is really needed. I?m also looking at it with the wings on edge in a stand and balanced on the plane it will be a lot different.
 
I flew the first 25 hours off with out the springs in the system. I wanted to feel what the roll forces were without the springs. The plane is quite a bit more stable then all the other RVs, with the exception of the RV10. I just installed the springs but have not yet flown the plane to see if there is a difference in feel.
 
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