COLLET AND MOTOR SPINDLE MAINTENANCE
Keep the collet clean by brushing loose dust away with a little brush, and cleaning off resinous deposits with a little solvent on a rag used as a ‘pull-through’. If the collet is one of the two-part types, pull the ‘thimble’ from the nut for cleaning, but don’t forget to snap it back into the nut.
Small bristle brushes can be bought from household/hardware stores, and you can get sets of brass brushes specifically for collet cleaning.
Clean the inside of the tapered motor spindle in the same way, and make sure that the mating surfaces of collet and spindle are clean and free of bumps and deposits.