I will go on what I was instructed in my LSA Repairman class. After a long discussion on this very subject, the instructor (an A&P with AI) made perfect sense to my engineering perspective. A mechanically locked nut and bolt, by definition, must be loosened to align the cotter pin. This will allow the hardened ball of the rod end bearing to rotate on the soft bolt shaft, which will cause wear.
Using a nyloc bolt allows the hardware to be tight on the flat sides of the ball in the bearing, making this hardened ball rotate in the socket it was designed to move in. There is no movement of the hardware in relation to the ball or the actuating fork in the joint. So there is no concern of loosening the nut on the bolt or grinding wear thinning the shaft of the bolt.
Av8r3400 Kitfox Model IV
The Mangy Fox
912UL 105hp Zipper YouTube Videos
I agree with you Av8r3400, my
Mechanical mindset says the same thing, if it were tapered like a tie rod end it would be a different story because then a castle nut and cotter pin would be exceptable because there are 2 forces working to keep it in check , where the bore of the hiem joint is not tapered you must rely on friction of the nut and bolt compressing the flat sides of the ball/ bearing
Thanks for all the replies, interesting discussion. I had another question: As I'm working through hooking up the connecting rods I came to the rear belcrank for the elevator. With everything square I can only get one washer (960-10L) between the bearings and the mounting tabs (as in one on one side of the assembly), there should be two, one on each side between the mounting tab and bearing surface. This fit is perfect with the exception of missing a washer. Is it preferred to remove material from the bearing surface? Removing material from the mounting tab doesn’t seem like a good choice although I removed the powder coating from both tabs on the inside. Is not having a washer satisfactory on one side? Manual states to shim as required but I am assuming that means to use a combination of 960-10 and 960-10L to achieve the proper fit with a washer on both side of the bearing mounting tab surfaces? Thanks for your input.
I returned to finishing the tail assembly after working on the fuselage while playing with Superfil which like Esser I super-suck at but, sandpaper allowed me to in the end be victorious.
The issue I have run into is that when I install the trim motor assembly in the lower fuselage mounting tabs I find that at the other end the rod end & scissor links are out of alignment by a little more than the width of the rod end (+.4”). The right side of the rod end is laying against the outside of the left side mounting tab on the fuselage.
I’m not too excited with the options I have come up with to remedy the problem and have not found any posts that deal with this. I’m hoping I’m missing the simple solution. I would appreciate an any ideas.
Thanks for responding. I have worked with it a bit and this is the best I can do. In the one pic you can see that the shaft is not square which to square I think I would need to bend the lower fuselage tubing which I not to excited about. Bending the upper tabs or putting a side load on the trim motor's lower mount tabs doesn't seem like a good choice as the amount seems excessive.
Pop a bolt in the upper attach and zip a reamer through the lower mounts
and then decide if the slop is excessive. If so then drill out the tabs to the size
that allows a shouldered bushing. If the slop isn't that bad use it as is.
Or cut and reweld one of the tabs.
Lacking welding facilities the shoulder bushing option would be an easy fix.