[mvaughn]

Oz,

For me, a boost in voltage with a better quality power supply made all the difference in the world. I started with a PC power supply from a scrap computer that could barely spin one motor at 15 ipm speeds with the 1/2 - 10 tpi leads.

Hooking up more than one motor would trip the internal overload protection of the power supply and shut it down.

I purchased a 24 volt PS rated at 4.5 amps and have gotten much better performance and speed. I don't think my current MDF machine could handle cutting at 60 ipm, but for rapids it's no problem.

Have you checked to see what voltage and amps are reaching your steppers. They should be able to spin a steeper lead screw at lower RPM to get better speeds. The torque will drop off at higher RPM's, if you lowered the RPM's and went with a 10 tpi lead screw you might have good results.

-Mark