what comprises as step (was Re: Why is my feedrate slow with stepper motor

> By eliminating the driver,
> I was able to increase my
> max speed from about 900
> steps/second to 4000 steps/second.

I am awaiting arrival of my Gecko's so am still in the dark about
this question.

If one builds a stepper control and uses the 4,000 pulses per second
from the computer, one might get 4,000 steps, or one step per pulse.
an example is a 400 step per revolution stepper would achieve 10
revolutions per second, at the 0.9 step angle per step.

If I am not mistaken, the Gecko uses a micro step and breaks that
into 10 parts of a step or 1/10 step per pulse. This would mean that
it would drive a stepper 10 times slower, but with 10 times the
positioning accuracy of a full step drive. or 10 pulses to get the
same 0.9 deg as above.

In the example this morning, 2:1 on the timing belt, 10 TPI lead
screw was a slow drive. 4,000 pulses AND 4,000 steps per second
would spin this at 10 revolutions/sec and spin the leadscrew at 5
revolutions per second. That is 30 inches per minute if my math is
right. (he should expect that sort of speed)

Changing the gearing to 1:5 (from 2:1 ; two motor revolution=1
leadscrew rev) would increase the leadscrew revolutions to 5
leadscrew revolutions per stepper revolution, but by using the Gecko,
the same leadscrew speed would be achieved, AND the same positional
accuracy would be had. (assuming same voltage) but delivered power
would be less (10%?) but motor smoothness greatly improved. And high
speed power would be greater.

Of course, 40,000 pulses per sec is possible from some DOS based and
Linux based programs so things can go faster.

Am I right on or all wet ? (or maybe just a little damp?)


Dave