I have an X1 mini mill and I am thinking about improving the spindle drive so getting rid of the plastic gears etc. In fact I would discard the motor/contoller and the box that contains it all.
What I have is a (bit oversize) BLDC Electrocraft servomotor and BRU drive and am considering a belt drive by mounting it behind the column so that the belt passes either side of the column. I anticipate that the motor will be bracketed off the head casting which means that I will need some sort of splined shaft on the mill spinndle to accommodate the 30mm or so quill movement. The motor I have runs up to 4000 rpm and I intend to have a 4:1 pulley ratio to give me 16,000 rpm max.
I have set the drive up so that the motor speed can be adjusted with a potentiometer so in some ways its just like a VFD on an induction motor but maybe its not not as good as a VFD as there is no built in accel/decel feature?
I know many people have modified their machines to belt drive, usually using the original motor but I would be interested to hear any comments on my scheme.
Ian Phillips
Cheshire UK