help, i have this spindle motor chinese, gdz-100-3 , 220v 3kw, 24000rpm, it started to sound little weird, but very subtle like it has a beating something like that, its working fine, but like i said its very subtle that, but its started and it does not want to sound normal, the inverter its fine, everything its fine, jut that sound of the spindle, please help, pm me if someone has some answers!