Rod end bearings - aileron pushrod

A week ago I was installing the yoke-to-bellcrank pushrod for the right wing on my RV-7A when I thought, "I should check to be sure that half the threads in the rod end bearing are inserted into the pushrod.

I was surprised that they weren't and further surprised that it wasn't the proper rod end bearing on the pushrod I was looking at on the plans. "How did this happen?" I wondered. I just assumed that I must've put the longer rod end bearings in the HS or VS and at this point, I'd rather spend the money than take those apart.

So I ordered two new rod end bearings ($14.95 each) and installed them this weekend.

Today I took the left one off and, I'll be darned. Same problem.

I doublechecked the plans only to discover I was looking at the ELEVATOR pushrod callout, not the AILERON callout.

I also doublechecked that the pushrod was built to exact specifications lengthwise. It was. Even in the plans, it appears that half the threads aren't engaged.

So I'll order two more rod end bearings and construct it to the -- in my opinion -- safer elevator pushrod specifications.

My plans are pretty old, as I'm builder #240. Can anyone who's got newer plans check to see if Van's has changed their callouts here?

Bob,

I had a similar discovery. I was actually pretty pissed off that two different rod end dash numbers were in the same bag and no real distinguishing markings.

You have a longer one installed somewhere. Obviously that's not a big deal, but clearly having one installed that is too short is a major problem. This should be a service bulletin IMO.

Bob,

if I remember correctly that is a typical problem, the called out length for the pushrod seems to be slightly short. A popular remedy is to add more jam nuts to the threads and so reducing the length of "exposed" thread (and therefore circumvent the possibility of the pushrod wandering far enough on one rod end bearing to unskrew on the other end)

Use M3616M

Bob,

This has been discussed before and is a common problem. The best solution (imho) is to use the longer rod-end bearings. That will give you the required 1/2 threads engaged. On my aileron push-tubes, one longer bearing was required on each tube, but if it is still too short, you can change all four to the longer ones. Use M3616M instead of M3614M.

Best regards,

mdevans9 said:

Bob,

This has been discussed before and is a common problem. The best solution (imho) is to use the longer rod-end bearings. That will give you the required 1/2 threads engaged. On my aileron push-tubes, one longer bearing was required on each tube, but if it is still too short, you can change all four to the longer ones. Use M3616M instead of M3614M.

Best regards,

Click to expand...

Right. That's my plan. I ordered two for the right wing a week ago before I realized that the mistake wasn't mine, it was Vans'. Now I get to pay more shipping charges.

One of these days, i'm going to assemble that manual of all of the mistakes and gotchas if you build exactly to plans.

Bob Collins said:

One of these days, i'm going to assemble that manual of all of the mistakes and gotchas if you build exactly to plans.

Click to expand...

Just wait until you finish your -7 and start building that -3 you have always wanted...."Instructions? Instructions?! We don't need no stinking instructions!"

Our motto - assume everything is wrong - build to fit!

I experienced the same thing:

http://blog.bowenaero.com/?p=369


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