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Rudder Rod End Bearings to nutplates
- Thread starter sdgern7a
- Start date
Rudder nut plates
If they strip, you've got a problem. I would not tap them out just yet - that kind of defeats one of their purposes - to help hold the rod end bearing in. They are really large, and I just can't imagine that they could get stripped by just trying to get the rod end bearing in. Perhaps if you screw the rod end bearing further into the nutplate the inconsistent resistance will smooth out. Also, try a bit of boelube on the threads. Good luck!
If they strip, you've got a problem. I would not tap them out just yet - that kind of defeats one of their purposes - to help hold the rod end bearing in. They are really large, and I just can't imagine that they could get stripped by just trying to get the rod end bearing in. Perhaps if you screw the rod end bearing further into the nutplate the inconsistent resistance will smooth out. Also, try a bit of boelube on the threads. Good luck!
alpinelakespilot2000
Well Known Member
They should go in relatively easy with Boelube and some type of tool to twist them with. If they still don't, did you check to make sure the hole in the rudder spar is aligned with the nutplate threads--if not you may be trying to cross-thread them,which would account for them going in a few turns then loosening, then tightening up again. If you need an idea for a tool to twist them in with, I can find the link to the directions for the one I made. I would definitely NOT tap the threads on the platenut--the platenut is intentionally designed to work like a locknut. I didn't have any trouble on my -9 rudder (which is now the same as the -7s) so hopefully something along the lines of the above will work.
Good luck.
Steve
Good luck.
Steve
Through Hole Clearance
As suggested above, the through holes in the material may not all be perfectly concentric, and the nutplate may not be on the same center. If they're off even a smidgeon, getting the threads engaged is difficult and ragged rotation may be evident.
You're going to be installing a billion nutplates. You will encounter this problem if it isn't already before you. My workaround is to first drill to nominal thread OD, temporarily install a screw or bolt to hold a nutplate to the hole then use the nutplate as a drill guide for its rivet holes. This precisely locates all features, except it isn't good enough when you add up all the tolerances that can go wrong at final installation, and the alignment problem is still a risk.
The trick? Before riveting the nutplate in place, drill out the screw hole one size larger on the unibit. Do this also on all the mateing parts and covers, especially the large ones.
John Siebold
As suggested above, the through holes in the material may not all be perfectly concentric, and the nutplate may not be on the same center. If they're off even a smidgeon, getting the threads engaged is difficult and ragged rotation may be evident.
You're going to be installing a billion nutplates. You will encounter this problem if it isn't already before you. My workaround is to first drill to nominal thread OD, temporarily install a screw or bolt to hold a nutplate to the hole then use the nutplate as a drill guide for its rivet holes. This precisely locates all features, except it isn't good enough when you add up all the tolerances that can go wrong at final installation, and the alignment problem is still a risk.
The trick? Before riveting the nutplate in place, drill out the screw hole one size larger on the unibit. Do this also on all the mateing parts and covers, especially the large ones.
John Siebold
Thanks Guys.
I ran a thread die over the threads to clean them up on the rod bearing.
I then found that the shim behind the horn had a very slight edge raised in the hole that the threads were catching on. I cleaned that up and added lube to the bearing . Went right in...
Thanks,
Scott
I ran a thread die over the threads to clean them up on the rod bearing.
I then found that the shim behind the horn had a very slight edge raised in the hole that the threads were catching on. I cleaned that up and added lube to the bearing . Went right in...
Thanks,
Scott
RV7Factory
Chief Obfuscation Officer
Scott,
Glad to hear you got your issue addressed. Now, get back to work, those wings arrive in a few weeks!!!
Glad to hear you got your issue addressed. Now, get back to work, those wings arrive in a few weeks!!!
This is an old thread i dug up but,
I have unpacked the nutplates as i'm about to install them to my rudder spar.
When I twist the rod end bearing into the nutplate (in my hands, not installed) its is very difficult to turn.
When removed the thread on the rod end bearing looks like the is damaging sections of the nutplate. Sections where the nutplate is not round.
Is this normal? Should i keep driving it.
It is not cross threaded.
I have unpacked the nutplates as i'm about to install them to my rudder spar.
When I twist the rod end bearing into the nutplate (in my hands, not installed) its is very difficult to turn.
When removed the thread on the rod end bearing looks like the is damaging sections of the nutplate. Sections where the nutplate is not round.
Is this normal? Should i keep driving it.
It is not cross threaded.
scsmith
Well Known Member
should be OK
hydnc,
the nut plate has purposefully been upset into a non-circular threaded hole so that it acts like a lock nut. So, yeah, there is some resistance and will probably clean the plating off the threads of the rod end bearing when installed. Thats normal.
If you find any actual metal shavings on the parts on disassembly, then you may have the problem that was the subject of the original post -- the ruddr spar hole is a bit off center or a bit undersized, and is guiding the rod end bearing into the nut plate in a bad way.
hydnc,
the nut plate has purposefully been upset into a non-circular threaded hole so that it acts like a lock nut. So, yeah, there is some resistance and will probably clean the plating off the threads of the rod end bearing when installed. Thats normal.
If you find any actual metal shavings on the parts on disassembly, then you may have the problem that was the subject of the original post -- the ruddr spar hole is a bit off center or a bit undersized, and is guiding the rod end bearing into the nut plate in a bad way.
A Word of Caution!
Please do NOT do this! AN threads are "rolled" not "cut". When you cut the threads with a die, you are damaging them.
Please do NOT do this! AN threads are "rolled" not "cut". When you cut the threads with a die, you are damaging them.
Wayne Gillispie
Well Known Member
You can run a DIE over the threads IF
you grind off the crest of the tool so that it does not re-cut the roots of the o.d. rolled or j thread your trying to repair. Just purchase separate dies and mark them appropriately so as to not mix them up. J thread dies are very difficult to find.
For using a TAP, there is no difference. Chase the threads as usual except not on self locking nuts/nutplates.
The rolled or J thread is used in the aerospace and automotive industry to increase fatigue strength by 40% and shear strength by 10%. One reason for not using hardware store bolts in your airplane.
If I damaged small inexpensive hardware I would just buy new. If I was to damage "critical hardware"(wing attach bolts/prop bolts) I think I would also buy new. Anything in between I might want to repair as above.
you grind off the crest of the tool so that it does not re-cut the roots of the o.d. rolled or j thread your trying to repair. Just purchase separate dies and mark them appropriately so as to not mix them up. J thread dies are very difficult to find.
For using a TAP, there is no difference. Chase the threads as usual except not on self locking nuts/nutplates.
The rolled or J thread is used in the aerospace and automotive industry to increase fatigue strength by 40% and shear strength by 10%. One reason for not using hardware store bolts in your airplane.
If I damaged small inexpensive hardware I would just buy new. If I was to damage "critical hardware"(wing attach bolts/prop bolts) I think I would also buy new. Anything in between I might want to repair as above.
Wayne Gillispie
Well Known Member
I don't know if I would recommend using a unibit...the steps are pretty big.
I usually drill for example a #10 hole for using my nutplate jig as a #12 is too small for mine. This works in most installations to provide a little clearance for the bolt or screw. Sometimes I might open hole up with a #8 after drilling nutplate attach holes. On holes that are countersunk it is usually not a problem because your hole is going to be enlarged during that process.
I had one of the rod ends on the VS/Rudder that was not threading correctly and all attempts to get the first turn in the nutplate was futile. I ended up getting the appropriate tap, and just ran it in a few turns to get the beginning portion of the nutplate to clean the threads. I didn't go in far enough to take out the locking feature. After that I was able to get it in and started with some boelube, then it was fine.
