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General Mach Discussion / Motor Voltage question

« on: November 29, 2011, 05:33:32 PM »

I am trying to fine-tune the Bridgeport mill I recently bought.  Lots of pictures here: https://picasaweb.google.com/113966569709555812037/BridgeportPart1 and https://picasaweb.google.com/113966569709555812037/BridgeportPart2

These are the motors, and the info I was able to find on them:

Sigma pacific scientific
Bipolar stepper motor 4 wire NEMA 34
Model number 21-3437d200-B038
phase resistance 0.5 ohms
phase inductance ~680 mh

And then this:

Break down of model number
21-3437d200-B038
21 is the motor series
34 is the frame size NEMA 34
37 stands for 2 stack
d200 is the number of steps per revolution
B is a four wire motor
038 is the phase resistance

Modern model number is H32NRHA-LNN-NS-00

Phase current 5 Amps
Phase resistance 0.38 ohm
Phase inductance 0.38 mh I did fry my multimeter after all damn it
Holding torque 460 oz-in

Info from searching the part number and finding this thread: http://www.cnczone.com/forums/diy-cnc_router_table_machines/105716-need_help_identifying_large_bipolar.html


So, I have been learning Cambam, and have even cut some parts successfully but in my quest to know more I measured the power supply voltage and found it was only 20 Volts (Nameplate on it says 24v as seen in one of the pictures).  The controllers are homemade I think...I feel that I can stall the motors quite easily.  I have read numerous thread talking about 24, 36 and even higher voltages?

Questions:

1) What voltage would be best?
2) Any other recommendation based on the pictures?

Thanks, Kenny