Servo install

[Ron_B]

Before I signed up a few days ago I viewed a servo installation photo of what I believe was in a Sonex on this site. First I must say, I know nothing about autopilots other that I'm starting to install one in my RV-10 (under construction) . I do know a little about adel clamps.
In this photo the owner attached the non-servo rod end to an adel clamp that was clamped arround a control tube for the aircraft. I could not comment while viewing as I did not have my pass working and was not logged in. I'm concerned that if this adel clamp would slip (as they do some times) it may create a jambed control . If someone can locate this photo and shed some light on my concern I would appreciate it.
Thanks Ron

 

[mcr01passion]

I totally agree with you... :-[

This was these photos (not my aircraft... a Remos G3, I think):




MCR 01 Passion
MCR 01 VLA, also known as La Fayette Sporster.
http://mcr01passion.forumperso.com/portal.htm

 

[Ron_B]

That's the one, Dynon what do you think?

 

[dynonsupport]

Without giving specific advice, here are a few thoughts....

If you're using the servo limiting bracket - as it looks like this customer has - then the servo can't go over-center, period, and you're protected from that sort of lockup.

Next, if the clamp completely loosens, it slides back and forth, and you're basically free of the servo anyway.

Now if the clamp loosened in some particular way and managed to slide one way, but catches the other (sort of ratcheting), then you may have an issue. But how likely is this? I have no idea.

The requirement to be safe, of course, that you have a positive lock between the arm and the rod-end, and also between the other rod-end and the place that it is connected to. This can be obtained a number of ways, and I'm hesitant to squash any particular approach outright.

I guess I'll also mention that Adel clamps aren't really particularly meant to be structural in this way, but as homebuilders, you have a lot of license to design and test your own solutions that work.

The generic preference is to attach right to a bellcrank if you can. Some people have welded on a tab to their torque tube, which is then either attached or not, should it break.

 

[gianmarko]

i dont like that solution at all, i would recommend using a rigid connection, or at least a couple rivets between the collar and the control rod.

 

[PhantomPholly]

I drilled all of the way through the Adell Clamp and inserted a bolt / castle nut / cotter pin. The only possible failure then is if the servo push rod comes loose - in which case it won't be likely interfering with the control rod anyway. Too, using my method the limit device becomes superfluous - but if you are a "belt and suspenders" kind of person, it won't hurt to leave it in.