Re: [CAD_CAM_EDM_DRO] what type of stepper motors?

Terry,

A little funny way to express it, most likely the author just got a
little confused. Steps are accomplished by switching currents in
stepper motor windings. Yes, you can use CPU instructions to cause
hardware to switch the currents. After that, the correlation ends.
Very doubtful (unless one builds a special processor) if there are
instructions designed EXACTLY for each of the stepper state transitions
(I.E., winding A fwd & winding B reverse, winding A reverse & winding B
fwd, ...) maybe, but I doubt it. Typically it takes a "few"
instructions to change the levels on a few port bits to a new pattern.
Even if it's step/direction, one usually gets a value from a circular
table, increments the pointer into that table (OK, that one might be
free), outputs the contents to a port, delays or waits for the next
request for a step (an interrupt). At any rate, a "few" instructions.
And it's not really important to the user if it takes 10 or 50
instructions to do a "step". BUT, a stepper motor physically having 200
steps per revolution vs. one having 400 steps per revolution IS
significant. As is microstepping at 10 steps vs. say 100 or more
steps. Probably just a little confused.

Hope I haven't confused you more.

Alan


terrylr@... wrote:

>
> hello;
>
> i happened across this web site late this evening.
>
> http://www.torchmate.com/catalog/page6.htm
>
> i am not sure what he means by the below:
>
> <begin quote>
> Our high resolution electronics
> provide 400 steps, or computer
> instructions, per revolution of the
> motors. This results in a minimum
> directional movement of .00163".
> <end quote>
>
> there is a big difference between 400 steps
> per revolution and 400 computer instructions.
> am i reading more into this then what is meant?
>
> anyone happen to have an idea what type of stepper
> motor is he using. the stepper motor will either
> be driven at 400 microsteps per revolution or 1600
> microsteps per revolution.
>
> --
> Terry L. Ridder