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Culprit

RepmikeBrown

Well Known Member
Big milestone today. I finished installing wings, plumbing, wiring and checked all of my aileron up and down movements. The stick movement seemed a little heavy left and right but ok forward and aft. I probably wouldn?t have ever second guessed the heaviness had there not been another RV4 in the hanger next to me. It?s movements were effortless, but I did have the servos connected from an auto pilot installed. I thought maybe this added the extra drag in the controls. Not satisfied I disconnected the aileron servo and still had the heavy stick both left and right. I start with left and right aileron bushings/washers, any possible rubbing of close parts. Moved on to the aileron push rods checking all rod end bearings and washers. Next the bell crank and then the large push rod tubes all moving freely I install them back and still heavy left /right movement on stick. I examine the stick control for binding or interference, and then finally removed the heim bearings for inspection. I?m down 2 days so far, but finally found the culprit. The rear heim bearing has been damaged ever so slightly. The small crease on the brass
has also creased the interior of the housing race causing the bearing to bind. I just wished I?d started looking from that point first. Lesson learned.
2cht5jd.jpg
 
That type of damage is often caused by careless use of a wrench to tighten the bearing. Good catch!
 
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Whatever the cause, kudos to Mike for chasing it down, and not blowing off the control drag, as we see so many do.
 
Mike, nice catch. Could that damage have been from the two rod ends on that particular pushrod being clocked with a "twist", causing binding? It almost looks like a washer was grinding into the brass.
 
The only thing I can think is yes, plus over torquing which caused the damage

Over torque would not cause this damage as there should be nothing crushing when doing so. A bolt could fail due to that this was cased by one of two things, rod end bearing frozen causing it not to center or the two ends not being aligned causing a washer to extrude the brass. Due to the damage I think that replacement of both ends would be in order not just the one with damage as there was a reason it stuck.
 
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