1, Please check if the set screw which fastens the bits is loose or not. If the screw is loose, please use the hex key wrench to fasten it.

2, Please do as follows to reassemble the collet. There is a small gap between the collet and the motor.

3, If the problem persists, the diameter of the collet may be a little bit big. Please fill in the warranty request on our website and contact support@snapmaker.com for assistance.