Guys,
I had a servo screw vibrate off today. There was no crash, but I was wondering if I should be using a tiny amount of threadlock on it ? The servo I am talking about is Align ones - DS610, 620 and 650.
These seem to have a metal center, and the screw is also metal, so a threadlock might be effective here ?

I know threadlock attacks plastics, and Hitec specifically asks not to use, but this is a metal to metal contact, so a tiny threadlock is justified ?

Never felt the need for the same, although it should be fine on such a metal-to-metal contact.  Possibly you did you not tighten them enough the first time around ?

And be sure to use the blue ("semi-permanent") ones !  I have seen/known many people struggle with removing the red ("permanent") ones when they ever need to !

i had a similar issues on my servos too.. and yes a bit of 242 loctite will suffice and its somtimes recommended too..

Well, I do use loctite on tail servos with the DS480. What I do is I use a small amount of 222(light strength) loctite. I feel its better and safe.

How I use it is,
1)I make sure servo is between screw head and servo mount.
2)I initially fully tighten the screw so that it comes completely on the other side of the servo mount(which is metal.)
3)Now I apply the loctite on the threads, and unscrew the screw a little - as much as only the part of the loctited screw sinks into the metal mount and then tighten it back.

This way it will not touch the plastic. Beware, even a milli drop will eat plastic and make servo less safe/useless.

Gaurav,

The core problem seems to be vibrations in your model. What type of propellsion are you using, elctric or nitro. If you are having 4 stroke eng you are bound to have more vibrations. Try & minimize the vibrations. But as Anwar mentioned there is no need of thread locker for servos as the are designed for these sort of vibrations. But if the problem persists & if you are using metal gear servos you can try Loctite 222(purple removable). While using loctite be aware that for servo screw just a dot should be good enough.
Goodluck.

Raj

Sorry about my previous post, I was thinking abt using loctite on servo body screws. BTW I use loctite on the tail servo center as well, as both the screw and gear are metal.

I initially dip the screw driver into Loctite and apply inside the metal gear thread. Then put the servo arm and screw and tighten it. Note that you need to use very less amount of 222 loctite.

Thank you everyone for your suggestions.

majraj,
I agree that vibration is the root cause, and I have been able to identify the issue. The tail rotor blades had a little bit of slop in them, and that might have caused the servo screw to come off the servo. I am glad i found it during a routine checkup, and before it could have caused any crash.

Vinay, Anwar, Sujju,

Yes i will use a very tiny drop of blue locktite. Hopefully that should be the best assurance.

Thanks
Gaurav

FYI 222 loctite is PURPLE and the least strength loctite available.

EDIT: ITS PURPLE

http://www.google.co.in/images?q=loctite%20222&um=1&ie=UTF-8&source=og&sa=N&hl=en&tab=wi&biw=1680&bih=933