RV-4 Add a Flight Control bearing?

[bonanza9972r]

Recently I noticed some “slop” in my RV-4 control Stick. Primarily the left/right aileron motion. I admittedly like my flight controls like a good formation flight (nice and tight). The culprit is not the brass bushing in the control stick but is in the hole drilled in the steel column carrier. (Not sure what Vans actually named that piece).

So…..thinking of drilling oversize from 3/8 to a 1/2 inch hole and pressing in a very beautiful bearing I got from Amazon. Seems like there is enough meat in the column carrier. Anyone care to talk me out of it.

Yes…I realize I can do a bearing bronze bushing which will take a smaller hole than 1/2 inch but overtime and with use even brass will wear. Ball bearings on the other hand…..may last in the airplane longer than me.

See pictures for reference.

 

[rvbuilder2002]

Recently I noticed some “slop” in my RV-4 control Stick. Primarily the left/right aileron motion. I admittedly like my flight controls like a good formation flight (nice and tight). The culprit is not the brass bushing in the control stick but is in the hole drilled in the steel column carrier. (Not sure what Vans actually named that piece).

I wont try and talk you out of it... just mention that if over sized holes in the control column were causing your lateral slop in the stick, then it is likely that everything was never installed correctly.

When assembled as intended, the brass bushing and the bolt hardware are anchored to the control column and do not ever rotate. The stick pivots / rotates on the captured brass bushing.
This way the holes in the control column should never get enlarged and any wear that occurs should be on the softer brass bushing which is easily replaceable if ever required.

This is the design intended function on all RV models any time a brass sleeve bushing is being used... It is intended to be captured with the assembly it is within, rotating on it.
The reason that castellated nuts and cotter pins are used on the bolt that passes through the brass bushing is that torquing the bolt to standard torque value typically will distort the bushing and cause friction in the rotation of the assembly that is pivoting around it. The castellated nut allows for torquing just tight enough that the bolt and bushing will never rotate, but not enough to cause binding.

So installing bearings may be ok depending on how it is done, but there was never meant to be any rotation at that point in the control column.
As for the "depending on how it is done" part... the two sides on the control column are not parallel to each other, so you can't just install a bearing on each side, flush with the surface because they will not be aligned with center line of the bolt.