Diagnostic for Generating Step Signals

In my opinion the primary reason for stepper motors to stall is poor
step signal stability. With a scope this shows up as jittery step
signals.

There are many recipes for creating step signals using a
microprocessor. I found a method of frequency synthesis that
creates very high fidelity step signals.

What I found is that motor and controller configurations that had
been stalling at 10 – 12 revolutions per second could be driven to
speeds in excess of their ratings. NEMA 34 motors really can run at
1800 rpm, that's 60,000 steps per second using the G201.

There is a diagnostic built into my SuperCam program that I use to
test motors and controllers with. Diagnostic mode is entered by
Control-B or entering BENCHMARK. The diagnostic can output up to
99,600 steps per second with a 1Ghz CPU. It works via the parallel
port.

A demo version of SuperCam is at:
http://www.super-tech.com/root/scdemo.asp

A more detail description of the Benchmark command is at:
http://www.super-tech.com/root/supercam/cmmds/default.asp?
cmmd=benchmark

SuperCam does not execute on XP computers, but if you have a Windows
98 or DOS system it can be quite useful. The Benchmark command is
intended to be used with motors on a bench, NOT on a machine. There
are buttons present that will cause the motors to be spun up to
speed and they will run indefinitely, which can be catastrophic if
the motors are attached to a machine.

I have found that by providing good clean signals the performance of
a micro stepping controller can be more than tripled.

Merry Christmas to All

Dennis Bohlke
http://www.super-tech.com