Hello

After a few months of tinkering I'm slowly making progress. I manged to install a 32bit version of windows that is running Mach 3 and outputting the required pulses down the parallel port cable. Using the circuit suggested by Kit, and others, on the previous page I was able to get all axis running with reasonable success. I've also reconnected the micro switches that cut the power to the axis if they hit their maximum travel. Jobs left before I can start making chips; 1. Either revive the optical sensors on the mill or install more micro switches for homing. 2. Work out a means of powering the Spindle, this is where I could use some help.

The motor that powers the Spindle is a SEM DC Servo motor, model number MT30U4-36. There are a few DC servomotor drivers on eBay but they seem to top out at around 80V and this one runs up to 140v, any suggestions would be much appreciated.

Here's the info from the motor label
Model MT30U4-36 No.00262-004
Stall torque 4.5NM Amps 13.2
Max 4000 rpm 140V 75A
Tacho 9.5 V/KRPM IP44/65 IC 400
C2000
Ferrite Brushed DC Servomotor


I do have one other problem. The Y & Z axis move fine, but the X axis behaves in an odd way at full speed, bit hard to describe so I've uploaded a video with the link below. I have removed the motor from the machine and it runs fine with without any load, but connected to the machine it sort of cuts out at max speed. I can turn the lead screw without too much resistance so I'm not sure what's causing it? Any thoughts?

https://photos.app.goo.gl/6StZyicUyWeMPB5XA In the video the problems start after I run it at full speed, the first few small jogs are intentional. You'll hear a high pitched unhappy motor sound when it cuts out.

Thanks in advance for any help.

Dan