Idler Tension Question (Now With Bonus Shim Question!)

[Andy Walker]

Hey all...

I'm still working on my elevator idler, and have it almost ready for prime time. My question now relates to the plans statement to set the idler tension "snug, but free to rotate." This seems vague; does this mean the idler arm should be free to move on its own, or that there should be some tension there and it should only move when some amount of force is applied?

Mine is currently "free to rotate", in that it does not bind and is not too stiff, but it will not move on its own. It's not "free to rotate" in the sense that if I picked up the idler assembly the lever would move on its own. I was thinking mine is good to go, but then I started second guessing based on how an airplane controls operate -- the elevators should just move freely with no force required.

How much tension should this thing have, and how "free" is "free" ??

Also, what's the deal with "paper shims" mentioned in the plans? I'm a little cautious about using shims that would disappear if they got wet...

[142YX]

there should be virtually zero resistance in turning, and virtually zero slop or chatter in the assembly.

[Andy Walker]

there should be virtually zero resistance in turning, and virtually zero slop or chatter in the assembly.

Cool, thanks. Did you have to use shims (paper or otherwise) to get to that point?

[MichaelFarley56]

I think I ended up using one or two thin sheets of paper to make mine just a little snug and to ensure there was no "slop" in the assembly. I tried to do that with most of the brass bushings found throughout the airframe going under the assumption that the bushings would loosen up just a fraction through normal use over the first 100 hours of flight time.

As long as there's no slop you should be fine.

[Andy Walker]

I think I ended up using one or two thin sheets of paper to make mine just a little snug and to ensure there was no "slop" in the assembly. I tried to do that with most of the brass bushings found throughout the airframe going under the assumption that the bushings would loosen up just a fraction through normal use over the first 100 hours of flight time.

As long as there's no slop you should be fine.

Thanks Mike. Mine clearly needs to be looser. I'll loosen the bolts a hair, and if that doesn't do it I'll shim with paper.