Re: [CAD_CAM_EDM_DRO] Re: Re: PIC-Servo

>
> > From: "andrew abken" <kn6za@...>
> <s>
> > I would trash this system If I could find a way to run emc with direct
> > command control of servos, and do it on a hobby budget. I think some folks
> > are very close to comming up with just such a system, but until then Ill
> > keep making chips fly with pic-servos.

Well, I've been doing it for several years. Maybe you'd better define your
budget for us. For servos, you need not only motors but encoders. Careful
searching of surplus sources can usually find encoders at a reasonable price.
There are usually a few on eBay at any time.

You need an encoder counter per axis so the computer can read the position,
and you need servo amps and a way to command them. The old way was through
+/- 10 V velocity command signals, so you need a DAC per axis to send those
signals to the servo amps.

Velocity servo amps need a way to sense axis velocity. The old way was through
a DC tachometer, but many newer amps can use encoder signals.

Copley controls has some fairly inexpensive servo amps in a range of sizes,
but they are about twice as expensive as a Gecko drive, ie. around $200 ea.

I've got all the rest of it in a 3 board set, see < http://pico-systems.com/PPMC.html >
for more info.

Jon