Re: [CAD_CAM_EDM_DRO] Re: faster steppers

Ian,
I'm glad you are happy with the design. I don't have any experience with EMC
but from what I hear on this list it can drive steppers pretty well. Maby
you should just settle with the speed you get. However it's always fun to
experiment a bit.
Yeah, I know, it can be a bit of a pain to set the currents correct but I
figured once it's done you don't change it very often so I didn't put more
work in it - will do in the next version 'tho. Besides I wanted to hold the
boardsize inside the freeware-version limit of Eagle.

Looking forward to see those pictures! Good Luck.

/Henrik Olsson.

----- Original Message -----
> Hi Henrik,
> Yes, I am using you design of driver boards and they seem to work very
well.
> I did have a bit of trouble trying to set up the currents with the trim
> pots - it was a bit difficult to get a stable state ( Change the running
> current and the idle current changes and vice versa ) but they all worked
> first time and seem pretty rugged. When I get the machine finished I'll
post
> some pictures including the driver boards in their old computer case.
> I haven't tried driving the steppers through a function generator as I
> haven't got one. Before I hooked them up to the computer, I did a little
> test of the boards and motors using a very basic 555 timer chip oscillator
> to drive them but this didn't really tell me anything except that the
boards
> functioned OK. I have determined the maximum speed at the moment by trial
> and error and altering the ini file in EMC. This is a bit of a learning
> curve as I am working in metric unlike most others. However, I now have it
> so that, on a G0 command, the motor will drive the axis smoothly and
cleanly
> as quickly as possible without stalling ( I actually got it up to about
570
> r.p.m. but it wasn't rock solid and so I backed it off to 540 where it is
> happier. Even though the motors are not too powerfull, I can't stop the
> carriage with my hand at this speed so it should be OK.
>
> Ian
> --
> Ian W. Wright
> Sheffield UK
> www.iw63.freeserve.co.uk