07/09/2026
I put a new motor, variable frequency drive, and drive wheel into my 2x72 grinder this week. The old single phase 115v motor has been replaced by a 3 phase 220v motor that allows for adjustments to the speed. The motor is still being run on a 115v outlet via a new variable frequency drive, which steps up the voltage. This video shows testing the new motor by grinding the profile into an 8" wrench knife The new smaller drive wheel does mean that the maximum belt speed is lower than the old motor, but it feels very controlled and still seems to work at around the same speed on the metal. (This step is done with a belt that is already worn down, so it's not as fast as it could be.) I'm hoping the new setup will reduce heat buildup a bit, and extend the life of my contact bearings, which have been wearing out rather frequently. It is also noticably quieter, which is really nice.
