The Z axis mount I got for the mill was from a servo driven Bridgeport and not exactly matched to the Lillian...not that thats a problem for me! Minor modification to the head casting was required and that was sorted out. Because the old servo motor had a 5/8" shaft, and the steppers I'm using have a 1/2" shaft, I had to discard the pulley....the belt appeared to be an odd pitch, and so I ditched both and got new 5mm pulleys. The one has been fitted to the ballscrew for some time, the other is waiting payday to get another stepper.
Another problem was the mount holes of the servo motor being different to the stepper, and the shaft on the stepper being slightly shorter. So, yesterday afternoon I headed off to a friends to use his mill to sort that out. An hour later and I'd thinned the plate a little to let the motor sit a touch higher, and then drilled four new M6 mounting holes...as luck would have it, they just fell outside of the old slots!
Been playing around some more this afternoon. I've known from day 1 I could have trouble with the main spindle motor. The original motor fretted its shaft at the bearings, with the result the stator moved and chewed out the windings. Repais was going to be £750+VAT to have the shaft ground, plated and ground back to size, and then rewind. Too much. Especially with the belts we're getting at work only last 6 months and hundred squid a pop. So to that end I got a new 3hp standard motor, and its now got a 3 stage V belt pulley, and I've stripped the old varispeed drive out.
I've always thought the motor was too long to sit on the old top casing and I'd have to fabricate
or get Aubyn too.... a new top casing to hold it the other way up and down one side.....it was only when I started looking at it this afternoon......
It fits...but literally only just!
I've still got other problems to deal with....at the moment the pulleys are too high and are fouling the middle of the casing meaning I can't use top speed...i need to take it out and recess the back of it to let it sit lower on the old bottom pulley which is also the spindle brake.