Re: Help?? CNC PCB Drilling Machine

There is a simple stepper circuit which has been around for years, a
recent publication showing it is at:

http://www.reed-electronics.com/ednmag/archives/1998/032698/07di.h

Page down to "Inexpensive logic controls stepper motor".

It can be used with unipolar (K179) and bipolar (K159) drivers.
Inexpensive CMOS and MOSFET versions, which can handle about 6 amps
without heatsinks, are sold by:

http://www.kitsrus.com/

Schematics are available on that website too.

Alltronics sells the unipolar K179 for $10. PCB and parts. Six amps
(more with heatsinks) per axis - a three axis driver for #30.00.
That's inexpensive.

As far as copying things like magazine articles, is one copy not o.k.
under the "fair use" practice for scholarly purposes like Sammy's?

Grant

-- In CAD_CAM_EDM_DRO@yahoogroups.com, "turbulatordude"
<davemucha@j...> wrote:

> I don't think there is a real problem. I know that Johns schematic
> has been posted on this list in the past so it is not totally a trade
> secret.
>
> also, Sammy mentioned that he needs to design and build, so
> regardless what his eyes pass across, I assume he will modify it to
> some degree.
>
> I had the urge to send Sammy some of the schematics I have gathered
> over the years, but I am not sure what I have is all public
> information on the net. That said, I was reminding myself not to bow
> to temtation.
>
> An interesting note is that some of the old timers had to design
> circuits from the ground up or pay multiple hundreds of dollars per
> channel ! man, we have come a long way in this hobby.
>
> I have some $50 steppers that origionally sold for hundreds and
> drivers that at one time would have been worth hundreds so I thing
> $1,000 per motor at one time was cheap. now you can do an entire
> machine for less.
>
> Dave