Recently I have come across problems with my rock tumbler.  I have been running it longer then I ever have when tumbling polymer clay.  (Usually with a batch of clay I will take 36 hours to tumble it through three grits of sand paper and buffing.)  The last two weeks I have been polishings sea shells that I found in Maine.  I have done two grits, both being used for over 1 week.  The poor tumbler got a work out.

The first problem was with the original belt breaking.  The tumbler is a two barrel Chicago Electric.  The belts have a history of breaking.  I replaced that with a sewing machine belt of the same size.

The second problem happened when that belt over heated.  It got brittle and then started to shred.  To help with the over heating issues, we simply took the cover off of the motor compratment.  I will be putting mesh over it to keep things from falling into to motor.  So far it seems to be doing okay.  I am about to polish the shells which will leave the machine running for another week.