Doing my first annual. When checking the elevator control in the tunnel I found the jamb nut was loose about 6 turns. Upon further investigation I found that the F-1065 cross bar was scraping the safety wire which in turn had worked the jamb nut loose. This happens only when the stick is pulled all the way back and while all the back it moves left/right -- exactly what you do when landing.
I know for a fact this was not scraping when I finished the build. I believe the push tube just twisted enough to bring the safety wire straight up top. So this had to be fixed. My plan was to first remove the bearing from the assembly, loosen the other end and roll it to put the safety wire on the bottom so it could never interfere again. Then I was going to adjust the segments as necessary to prevent any lingering interference. .... Well, as soon as I started removing the nut/bolt holding the rod-end bearing, the safety wire fell out. The safety wire loop on the bearing side had broken and the safety wire was being held only by being compressed in the assembly. In other words, it was not doing anything at all.
This part in the RV10 is on-purpose designed to have the rod-end stick out far more than half the threads in order to prevent interference with the tube itself. The safety wire is meant to prevent the tube from ever turning and working loose. I know I built this to plans and had it checked by another builder at the time.
Based on this experience I'm not happy with this design. In my case the tube twisted enough to put the safety wire on the top where it was then the cause of the interference. Further, I believe the constant working of that safety wire back and forth during landing (especially when forward CG - like flying solo for the first 40 hours) caused the safety wire to work harden and break where it went around the rod-end. I'm not 100% sure what I'm going to do to prevent this from happening again, but I'm considering safety wire on both sides in such a way to prevent the push-rod from rotating in either direction.
I'm not special so I'm assuming I'm not the only one where this has (or is) happening. I suggest everyone have a careful look at this next time you have the tunnel exposed.
In my case I caught it while doing a control system check with everything opened up for my first annual. When I had the stick full aft and moved side to side I could hear something scraping. And that lead to this find.
From the plans. Page 39-10
What I found after disconnecting the rod-end bearing from the control assembly. When I first looked here I saw the jamb nut had worked loose. I tightened it by hand and kept looking at what was going on. When removing the bolt from the rod-end the safety wire revealed that it had broken.
I know for a fact this was not scraping when I finished the build. I believe the push tube just twisted enough to bring the safety wire straight up top. So this had to be fixed. My plan was to first remove the bearing from the assembly, loosen the other end and roll it to put the safety wire on the bottom so it could never interfere again. Then I was going to adjust the segments as necessary to prevent any lingering interference. .... Well, as soon as I started removing the nut/bolt holding the rod-end bearing, the safety wire fell out. The safety wire loop on the bearing side had broken and the safety wire was being held only by being compressed in the assembly. In other words, it was not doing anything at all.
This part in the RV10 is on-purpose designed to have the rod-end stick out far more than half the threads in order to prevent interference with the tube itself. The safety wire is meant to prevent the tube from ever turning and working loose. I know I built this to plans and had it checked by another builder at the time.
Based on this experience I'm not happy with this design. In my case the tube twisted enough to put the safety wire on the top where it was then the cause of the interference. Further, I believe the constant working of that safety wire back and forth during landing (especially when forward CG - like flying solo for the first 40 hours) caused the safety wire to work harden and break where it went around the rod-end. I'm not 100% sure what I'm going to do to prevent this from happening again, but I'm considering safety wire on both sides in such a way to prevent the push-rod from rotating in either direction.
I'm not special so I'm assuming I'm not the only one where this has (or is) happening. I suggest everyone have a careful look at this next time you have the tunnel exposed.
In my case I caught it while doing a control system check with everything opened up for my first annual. When I had the stick full aft and moved side to side I could hear something scraping. And that lead to this find.
From the plans. Page 39-10
What I found after disconnecting the rod-end bearing from the control assembly. When I first looked here I saw the jamb nut had worked loose. I tightened it by hand and kept looking at what was going on. When removing the bolt from the rod-end the safety wire revealed that it had broken.