Control stick assembly - Alignment

[LukeFrog]

I am in the process of mounting my control stick assembly. I mounted the sticks and carry-through linkage inside the torque tube assembly and noticed I wasn't getting equal deflection left and right (roll axis). I initially thought this was due to the fish-mouth of the torque tube not being central to the the stick bracket, but later noticed it was one of the stick pivot holes not being drilled square to the bracket (see picture). The stick doesn't interfere with the bracket itself (just), but this puts the bottom bush of the stick off-center to the torque tube and thus the aileron carry-through linkage becomes angled inside the assembly. This poses an issue for mounting as it's difficult to get the cables running squarely to the aileron pulleys. One will always be slightly forward or aft, depending how I mount it.

20230405_174056.jpg



My question is: Is there any remedy to this besides removing and re-welding the bushes in the torque tube assembly bracket and drilling it straight again? I had thought about simply trying to cold-bend the plate holding the bush at the bottom of the stick to center it, but this will then require a twist in the carry-through linkage

I haven't seen this issue come up in any other posts, so I'm hoping mine is just a one-off manufacturing anomaly

[Mark Goldberg]

Luke, you are seeing unequal deflection of the stick assy - but it would seem to me the more important thing is whether you get the deflection of the ailerons as spec'd by Bob. Without having the ailerons hooked up - it would be hard to tell whether what you see would cause a problem or limit aileron deflection to less than what Bob spec'd. Mark

[LukeFrog]

Hi Mark, thanks for your reply!

At this stage I'm less worried about the aileron deflection and more about the alignment of the stick sitting in the bracket. This is ultimately the root cause of the deflection issue, but I worry about the downstream effects of this misalignment: Excessive wear on pulleys, bushes, pivots etc. My assumption is that the link should run parallel inside the torque tube and it very much does not at the moment

[Mark Goldberg]

I do not recall hearing that anyone had pulley problems with those two pulleys on the lower longerons. On the very first kits from the factory 23 years ago (like N303AP), there really was poor alignment. We would move the stick assy as far aft as possible to get as good alignment as possible, but it was still not ideal. Those pulleys are still on Jared's plane 1,200 hours of flight later. Mark

[LukeFrog]

That's reassuring to know. Thanks Mark

[Battson]

I'm worried about about the alignment of the stick sitting in the bracket. This is ultimately the root cause of the deflection issue, but I worry about the downstream effects of this misalignment: Excessive wear on pulleys, bushes, pivots etc. My assumption is that the link should run parallel inside the torque tube and it very much does not at the moment

That's unfortunate it doesn't fit right. You don't want to wait for a new parts, ideally.

If you really want it centered, it seems a shame to have to cut and reweld it. First I would try heating the tube up with a gas torch, below the hinge point, and carefully bend it in very small increments. It won't need much. You could also flatten it a little, where the weldment extends up into the bottom of the tube.

I don't think pulley wear will be an issue at all. They can tolerate much more extreme angles.