RE: [CAD_CAM_EDM_DRO] Re: need components for stepper drivers

> Thanks Tony. The 3977 looks good. Jeff Demand said they were a little
> fussy about supply voltage, and that unplugging a powered motor was
> most likely to be fatal (to the controller).

That's true of all controllers I know of. Since you must design for the
lowest (I.Q.) common denominator, here's an idea: Use a DIN plug for the
motor. Have two pins on the plug that are shorter than the rest. These
two short pins are connected together in the shell of the motor cable.
They form an interlock for the power to the motor drivers. As the use
begins unplugging the motor (as you specifically warned against), the
power to the drivers is shut off slightly before the motor wires are
unplugged.

> Have you had any such
> trouble? Also, I'm a little concerned about limited availability
> (Newark only).

Their website lists three other vendors, plus you could probably buy
from them in small quantities.

>
> I'm the fellow who designed the Sherline CNC controller
> (see http://www.bmumford.com/cncindex.html)
> I'm thinking about a more versatile CNC package for sale to Sherline
> customers. So I need something fairly robust that can be reproduced
> with readily available parts. I used the unipolar Allegro 7044 in the
> existing controllers, but am considering a bipolar driver this time.
> The Xylotex product isn't too expensive, and I'm not opposed to
> buying a solution instead of reinventing the wheel.

You get more bang for the buck with bipolar. Plus other vendors won't be
able to say they have more bang than you since they use bipolar :-)

Regards,
JJ