I have these on the kit that I built and someone said I should locktite them as they would vibrate through the threads holding them on. Is this the best way to prevent some kind of failure or are there bolts that work better?

Thanks,

J

jrhelm

I use Loctite on ALL metal clevises. They do vibrate and "chew" the threads. On 4-40's I use Loctite and lock-nuts.

Safe Flying!

I've never used LocTite on them, and I've never had one "Chew through"

Agree with Min -- I have never had a problem with them.

I have had 2-56 clevis's strip on the threaded rod. Replaced with a high quality nylon clevis with locking metal pin. http://www2.towerhobbies.com/cgi-bin...?&I=LXWH32&P=7
A little bulkier but safe. I admit it has not happened often.

Don't forget that some metal clevices are 2--56, and some are metric thread. Don't mix metric clevices with SAE rods, or vice versa--you'll have problems. They are a close fit, but just loose enough to eventually "chew through" or "strip out." At least that's information that i've received. I always make sure now that my clevices match my rods. I prefer metal clevices--much easier to adjust.

At my LHS, the 4/40 stamped rods he carries seem to be tighter with Dubro clevises vs Sullivan. I've had to locktite the Sullivan's before.

I think a more appropriate suggestion would be that you frequently check your linkages for looseness. If the clevis is loose (has lateral play) on the threads, replace it. If the clevis is snug on the threads (no lateral play), then you can decide whether you would feel more secure with a lock nut or Loctite on the unit.

I'm flying one plane for a week or two, then hanging it up and taking one of the others to the field. At that time, I always go over the linkages. I have seen clevises loose on the threads, and I've replaced the pushrod as a result.

Loctite, Lock Nuts, Nylon Clevises, they all deserve an inspection from time to time, start inspecting linkages and decid how you want to maintain them.

Good luck,
Dave Olson

I have never used it either. Do use lock nuts on 4-40 clevises though. I won't touch a plastic clevis on anything with a motor. Save them for gliders. I have had one strip and lost a plane because of it, but only one. Never seen a problem with metal, other than one dough head that put the wrong size clevis on the wrong rod and it came off. that was a given that it wouldn't work though. The rest of his plane had problems too but he was one of the newbie "I don't need your help" type guys.

I see about one a year of those guys. That's enough to entertain for the whole year. Many dollars later, some of them ask for help.

I have seen many instances of the metal clevises wearing the threads off the rod and failing, both on 2-56 and 4-40 but more 4-40's on big gassers., I always lock the clevisis into position after getting the trims set. I usually just use a good grade epoxy instead of thread locker, seems to work okay. I've never had a plastic clevis wear out the threads on rod but I have seen a hard landing (i.e. crash) strip them.

i tend to use the lock nuts more than ever now. Last year I was getting ready to maiden my T28 and while I was cranking my saito 91 over, there was a lot of vibration from the starter being transferred to the tail. In about 10 seconds of cranking, I had srtipped the threads off of the elevator metal clevis.[X(] Glad I noticed before flying it. Sometimes I'll wrap the push rod threads with a little teflon tape.

Teflon tape is an excellent idea. I think I might actually use that one!

Hi!
Loctite metal clevises?? Why? The only thing you have to do is to put a counter locking nut on!
But don't mix metric and inch clevises!
I have used Kavan nylon clevises on pylonracing models for many years...No problem what so ever.
Regards!
Jan K
Sweden