Quote Originally Posted by SafeAirOne View Post
I didn't realize the bearing and ballnut/screw got significantly hot during machining.
The heat comes from the motors. We like to use big macho-Volts to overcome inductance which leads to eddy currents and heat. The problem is, what to do with the heat? You want to dump it in to the machine before your motors demagnetise, but you don't want to get it in the screws because you would be forever worrying about heat expansion.

Will you be oiling those taper rollers? I occasionally run oil down in to my spindle bearings and make a terrible mess. That's a thought maybe it is his choice of lube that is creating the heat.