Re: [CAD_CAM_EDM_DRO] Drives (boards) needed for small steppers, suggestions?

The L297/L298 bipolar chopper drives would be ideal for this. See the
data sheets and app notes at www.st.com. Parts cost is I think under
$25/axis, but it is probably cheaper in the long run to buy a kit with
a PC board - I think I've seen single axis boards for sale, and Dan
Mauch has a 3 axis kit.

If you want to get the maximum rated supply voltage capability of the
chips, you need to use a dropping resistor in series with the 7805
logic voltage regulator otherwise it will overheat.

I suppose you could build L/R drives or even drive the motors with
rated current/voltage if speed were no issue, but the chopper circuit
is pretty simple now that most of it is integrated on chip.

Chris

> Hello all,
>
> I just picked up on 4 astrosyn unipolar (6 wire) steppers real cheap
> ($4.40 each including shipping on an e-bay auction). They are in the
> 70-80 oz.in. range, 5V 1A and I want to use them to base a small
> gantry style engraver on. I'm not out to do any milling with these,
> just engraving.
>
> Although they are unipolar I want to preferably drive them in bipolar
> mode. I'm now looking for some drives to match up with the motors.
> The cheaper I can get them the better.
>
> This is just a little side line project I'm doing on the side from my
> g320/servo system. I've already got a fistfull of 1/2-10 ACME ss
> screw stock and I've figured out a way to make anti-backlash nuts
> from bearing bronze for this cheap engraver. The slides will be home
> built.
>
> Any suggestions as to where I can pick up some low cost drives would
> be most appreciated.
>
> Thanks,
>
> Donald Brock
>
>
>
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--
Christopher C. Stratton, stratton@...
Instrument Maker, Horn Player & Engineer
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