My CoreXY style printer doesn't have perfect belt alignment with its pullies, so there is some occasional squeaking on at least one pulley where the belt rubs against a flange. Since I don't have an easy way of adjusting the pulleys (maybe some tiny shim washers) I was hoping to just apply some oil to minimize the wear.

Could I just throw some 3-in-1 oil on the belt? Is there a better lubricant to use? I doubt that the belt would start skipping, but I am worried about damaging the belt due to some chemical incompatibility with the oil.

The belt is the most generic GT2-style timing belt you would find on a 3D printer, probably the same as this HICTOP 3D Printer Belt.


1 Answer 1


The pulleys on nearly every 3D printer I've seen are held in place on the stepper motor shaft with a grub screw. A bit of rotation of the pulley should bring into view this screw, which will use a fairly small hex wrench. Loosen the screw and slide the pulley in the direction appropriate to relieve the friction.

pulley with grub screw

photo courtesy random selection from pinterest

If you are unable to access the screws and choose to lubricate the belt, consider to use a non-reactive PTFE (teflon) type or silicone type substance and apply it sparingly to the belt edges. If the teeth of the belt and pulley receive the substance, you may not be able to avoid belt jumps under high acceleration movement.

  • 1
    $\begingroup$ Thanks for the suggestions. On the CoreXY style printers there are many idlers that are not attached to a stepper motor shaft, but are instead allowed to spin freely about a rod/bolt. They can only be adjusted up and down with spacers by disassembling and reassembling the mechanism, so it's a little impractical. I will try the suggestion of silicone lubricant. $\endgroup$
    – Mandias
    Apr 26, 2023 at 8:30
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    $\begingroup$ I used some silicone lubricant for treadmill belts and applied small amounts with a Q-tip near the pulleys. So far the squeaks have disappeared! $\endgroup$
    – Mandias
    Apr 26, 2023 at 20:15

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