I had a Crewson grinder and Axminster CBN wheel 120 and 180 grit ok for a couple of months then had trouble with noise from grinder, it was as it started up made quite a noise but then as speed grew came out, phoned Axminister who told me they were no longer agents for Crewson and gave me the number of the new UK agent, unfortunately was told the grinder is not built for Heavy CBN wheels suggest put back the original factory fitted, did this and noise stopped sold the grinder and wheels individually and bought a new grinder and BN wheels checking that it was covered for the weight of the CBN wheels.