I just finished setting up the new machine.
I am getting a notable vibration in a very specific rpm range (rather a frequency range) on both the high and low range. Literally, just below 950 rpm and it is smooth as glass, as well as just above 1100. Between these it is terrible. I don't remember the specific rpm range for low speed.
I tried running the motor without the belt and there was no vibration. I am not measuring any runout anywhere, and don't believe this is a matter of something being out of balance.
I think it may be an issue with the 3 phase motor when under load. I built a lathe this past year and had the identical issue, where I would run the motor between 43 and 49 hz and the motor itself would vibrate, almost like the VFD was causing some kind of weird resonant frequency pulsation as it was converting the DC into AC. I know that resonant frequencies deal with sound, but whatever the "resonant frequency" equivalent is for electrical stuff, I think I may be experiencing it. Not really sure, but it seems like way too tight a range to be a mechanical out-of-balance issue...
Either way, has anyone else who owns this machine found this to be an issue?
I plan on contacting grizzly monday. I do hope they can offer assistance...