Screws seem to demolish the thread inside the motors..!

Hionimi

Sky Pirate
Hi, was recently changing the arms on my Quad for differently coloured ones, and when trying to tighten the screws, they seem to start slipping, first feeling resistance, then it becomes less as if the threading was failing, I stopped immediately and felt if the motor is fitting tightly and it does seem so. Still, this does make me feel uneasy. Could this do any harm or should it be good enough? I did use medium Threadlocker by the way. The engines are Turnigy 2830/11's which have no 'stand', else I'd rather use tiewraps...
 

Craftydan

Hostage Taker of Quads
Staff member
Moderator
Mentor
Assuming you haven't stripped the threads from misalignment in past (sounds like you haven't, and they're kinda small), If they're damaged, it would be from overtightening -- this would imply to me, if the threads don't fail, you've got it tight enough. If this screw or none of the other scews look damaged, then it's likely the motor mount that's stripped. For that size, the only option I know of is to *carefully* drill and tap a larger size if the thread does finally fail.

Also, It looks like these come with X mounts. you could perminantly-ish mount the motor to these then zip-tie the x-mount to the boom.
 

rcspaceflight

creator of virtual planes
I assume that the screws have stripped out the aluminum of the motor. I've had this happen to a grub screw in a prop adapter. When I took out the grub screw, aluminum came out with it. Your best bet is probably to use bigger screws. But be careful and go slow. Let the bigger steel screw cut new threads into the aluminum and make sure you don't over tighten it. Probably turn in the new bigger screws without threadlocker and without mounting it to the arm to cut the new threads, then install everything with threadlocker.

If bigger screws will leave the aluminum too weak/thin, then see if you can find any sort of filler to replace what has been stripped out. I've heard of people using rope around the thread of the screw, but that was in bigger applications, not RC stuff. Maybe try sewing thread, or something, and wrap it around the screw and see if it's a tighter fit then. If that works, still use threadlocker when re-installing everything.

Either way, be careful not to over tighten. Rely on the threadlocker to hold it tight. I think.
 

rcspaceflight

creator of virtual planes
I assume that the screws have stripped out the aluminum of the motor. I've had this happen to a grub screw in a prop adapter. When I took out the grub screw, aluminum came out with it. Your best bet is probably to use bigger screws. But be careful and go slow. Let the bigger steel screw cut new threads into the aluminum and make sure you don't over tighten it. Probably turn in the new bigger screws without threadlocker and without mounting it to the arm to cut the new threads, then install everything with threadlocker.

If bigger screws will leave the aluminum too weak/thin, then see if you can find any sort of filler to replace what has been stripped out. I've heard of people using rope around the thread of the screw, but that was in bigger applications, not RC stuff. Maybe try sewing thread, or something, and wrap it around the screw and see if it's a tighter fit then. If that works, still use threadlocker when re-installing everything.

Either way, be careful not to over tighten. Rely on the threadlocker to hold it tight. I think.