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Problem: Motor Pully getting loose

Hi there!

I have been messing around with a new build and have come in to some problems…
My motor pully from DIY (@torqueboards) keeps getting loose. It has something to so with the small screws used to tightening the pully to the motor shafts will not tightened enough. It feels like the screw or the pully’s thread is too soft.

Has anybody else encountered this problem?
Or do you simply have a way to fix it?
I am considering spreading some loctide (blue or red?) on the shaft and on the screws to hold it in place, but I am not shure if it will hold…

It may be worth to mention that there is a recess in the pully hole which probably also is used to tightening the motor pully but the small part that should fit in the recess wasn’t a part of the kit?? That might solve too.

Please share your thoughts

don’t bother with the little set screws.

Replace the two on the collar with metric bolts. The middle ones that are under the belt don’t do much at all.

Are you using a keyway?

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when I first started, the I tightened one of the set screws to hard on my motor shaft and stripped the whole screw resulting me have to drill it out completely. for a much more firm hold, I drilled teeth into the pulley, cut a rode to size, and dremeled a flathead slot for tightening. works VERY well, never had slippage. oh yeah and there is a flat spot on the shaft.

now I have an enertion pulley and will be using a key.

As @CSN mentioned there are a few options.

  1. Replace the hub set screws w/ M4x6-8mm socket cap bolts.

  2. Add 2x 7mm C-Clips to the end of the pulleys if you have my motors.

  3. Use a keyway. If your not using the keyway your putting all that force on the set screw itself at least replace it with an M4x6-8mm socket cap bolt as it has much more surface area on the bolt head and you can torque it down.

  4. If you are using a round motor shaft that doesn’t have a keyway. Make sure to add flat spots and/or even flatten it so it’s a D shape and you can use a keyway + M4 bolts.

  5. Use thread lock but I don’t think it’s needed and is a bad option if you haven’t done the above options. I’ve never used threadlock and I have no issues.

Thanks for the thorough answers guys! I will probably start out with installing a key in the keyway and maybe replacing the screws. Replacing the screws just seem a bit cumbersome… The key for the keyway is not included in the mechanical kit from DIY right?

@OskarCastrone - It’s not. It’s included with the motor only.