Re: Steppers

> From: Charles Hopkins <chopkins@...>
> I will look in the control cabinet and let you know what I find. It is not

here at my home now.

> I think the top speed will still be the motors as the table is fairly

heavy.

>
> What step rate can be expected with the present EMC software?

It can step up to about 50kHz, but it's only usable (for me) up to 4-5kHz
because each successive increasing step is larger than the last. Since
stepper motor torque drops off as RPM increases, at some point the motors
won't be able to make the jump to the next speed (frequency). I have a nice
Excel spreadsheet that shows this effect if you're (or anyone is) interested.
If we go to the external hardware I described in a previous post we can
reduce the size of the frequency steps to a very small size throughout the
usable range of traverse rates. Another solution proposed by a fellow at one
of my metalworking club's meetings was to employ Direct Digital Synthesis ICs
which would allow linear frequency rate changes with a resolution of
something like 0.1Hz, and a range of 1Hz to 125Mhz! This is a little on the
complicated side to implement, but it is a nearly optimal solution and might
be appropriate for microstepping applications.

> I guess I need to first check out what I have for power supplies.
> I will get as much information as I can from the control box. That may not

be much as it was mostly striped when I received it.

OK!

Matt