We quickly put together this single stage axis to test various stepper motors and drivers. Made with 3/4" birch plywood, 1/2" drill rod, 1/2"x10TPI ACME screw and 1/2" ID bronze bushings purchased from Sears Hardware. I tapped a ACME nut out of delrin and used a skateboard bearing as a simple thrust bearing assembly. The mechanism moves pretty smooth with little backlash due to the delrin nut. Weights can be stacked on the wood platform to act as a motor load.
The stepper motor under test was a recently purchased Ebay find. It's an older Vexta PH265-05B-C12 1.4V 3.8amp nema23. No torque rating listed on the motor but I guess around 75oz/in. They were cheap, 4 for $45 +$15 shipping. They also have nice working HP encoders on them which will be removed and placed on some servo motors.
Using TurboCNC, we are able to move the axis at 75 inches per minute(IPM) with a 20lb weight to simulate a gantry load. Over 100IPM without the weight. The stepper motor driver used is our MicrostepPLD and it easily spins the motor over 1000RPM.
Vexta PH265-05B-C12 1.4V 3.8amp nema23 6wire
MicrostepPLD driver set at 8 microstep mode
Driver current limit set at 2.66amps
Stepper motor wired to driver in full winding configuration
Motor power supply set at 44volts
TurboCNC running on a Pentium233 laptop.