[kygreen229]

One more thread for the moment because I am stumped...

I bought some MPI servo arms and I need some little bolts to intall my control surfaces to the arms with the 4-40 ball links and linkage.

Went to the LHS and bought some 3mm bolts and thought for sure thats what size I needed,,,I was wrong these are a bit to big and the threads look a little different.

Anyone know what size you need for the MPI arms??

Thanks!

[GravyGoodness]

Really???

4-40 man. They are 4-40 arms and links, right?

[kygreen229]

yep really Im an idiot! thank you

[kygreen229]

Also when I bough this plane used it came with the arms and links still attached so I didn't know..seems like everything else has been 3 mm that I see

[GravyGoodness]

Originally Posted by kygreen229

yep really Im an idiot! thank you

I never called you an idiot.

If you dont know, then you dont know. At least you ask for help instead of pretending that you know everything.

[kygreen229]

No no I called myself an Idiot haha. I guess I just never thougt that it would of been 4-40. For some reason I was thinking that most all of these little screws are 3mm. They are close but no cigar!

Were dialed on the servo arms now. Are people using blue locktite on the servo arms or red? I dont want to use red just in case they need to come out but if its needed..

[BryceSteenburg]

Nope, nyloc nuts on the backside of the arm to link bolt. Slide bolt through the ball link, through the spacer, screwed through the servo arm, snug up and then a nyloc nut snug to the backside of the arm. Make sure the through bolt is long enough to protrude through the nyloc nut at least 1 thread. This help?

[wahoo]

Originally Posted by kygreen229

No no I called myself an Idiot haha. I guess I just never thougt that it would of been 4-40. For some reason I was thinking that most all of these little screws are 3mm. They are close but no cigar!

Were dialed on the servo arms now. Are people using blue locktite on the servo arms or red? I dont want to use red just in case they need to come out but if its needed..

Bryce does it just like I do except I use the blue on the bolt that goes into the servo output shaft.

[BryceSteenburg]

If you were refering to the servo arm retainer bolt, yep just as Wahoo said.

[Flatspinjim]

Originally Posted by BryceSteenburg

If you were refering to the servo arm retainer bolt, yep just as Wahoo said.

A dab of Silicone works great too.