How to tighten motor screws?

So our team’s screws for our shooting motor keep shaking out because of the slight vibration from our pneumatic wheel. It is a direct drive to the wheel, and the motor is mounted underneath a plywood board with two screws. We don’t want to use Loctite or any glue to hold in the screws because we want our motor to be replaceable in case anything goes wrong with it.

So has anyone else been experiencing this? We have balanced our wheel with metal bearings to reduce the vibration but our screws still like to come out and get jammed in the wheel. So are there any suggestions for fixing this problem like dampening the screws with rubber bearings or something like that?

Use Loctite, particularly red or blue. The idea is NOT to have the screws unremovable, for the reason you mentioned–red and blue do not make the screws unremovable. They do, however, make it difficult for anybody without the proper screw removal tool to remove them, which is exactly what you want. Don’t go overboard–one drop should be enough.

Alright, thanks! We’ll definitely try this!

One other thing. If you’re using really strong threadlocker, you’ll need screws whose heads aren’t going to strip out when you try to remove them. And remember that you can heat most threadlockers to remove them, if it comes to that.

A better method to hold the motor is a belly band mount. We modified a PVC toilet flange to mount the motor.

I love this kinds of engineering, please post picks.

Either Loctite or lock washers

Would you want to use loctite?
Wouldn’t it be bad if the loctite got into the motor itself?

Why are so many people afraid of Loctite? Use blue for easier removing of the screws.

Loctite cures in the absence of air where the threads mate so a little bit is all you need.

I recommend it be used on everything and use red on things that won’t be taken apart (or where you can get a lighter or small torch in to losen it.

If you want you can also use these http://www.andymark.com/product-p/am-1246.htm. They are great for gearboxes.

Blue (242) or Green (290) Loctite would be OK. Using Red (271) would require heating (400+F) for removal. I use 242 all the time on car motors fasteners, transmissions, and much more. Never had any problems. Usually, you would just coat the threads enough for coverage, but not have it dripping off. If you are careful and use a normal amount, it won’t get into the motor. I’m not sure if it would have any impact if it dripped on any of the armatures, brushes, bearings or other components.

Data sheets are on their site:
http://www.loctiteproducts.com/threadlocking-mechanical.shtml

Put a drop of locktite on the screw, not in the tapped hole on motor. Then it will spread as threaded in, and not be pushed into motor.

I’m not a fan of lockwahers, but perhaps try one under the screwhead?

Or these: http://www.mcmaster.com/#self-locking-socket-head-cap-screws/=le07rj

Don’t use lock washers - they are actually weaker than just using a plain nut.

Do not use red loctite it really is supposed to be heated to be removed. Blue is what you want, strong enough to do the job but weak enough you can remove it. I suggest the stick 37643 or gel 24010 as they are easier to use in the correct (small) amount and are less likely to go where you do not want it.

Edit: Another option is self locking screws like can be found here at McMaster-Carr http://www.mcmaster.com/#self-locking-socket-head-cap-screws/=le47xf They are the screw equivalent of nylock nuts.