Re: Digest Number 27

> Message: 6
> Date: Fri, 28 May 1999 14:47:55 -0700
> From: Donald Rothfuss <redfoot@...>
> Subject: Lap Top Computer as CNC Controller
>
> I'm lurking trying to learn about homemade DROs and CNC to see if I want to
> modify my Millrite. Would a Lap Top Pentium be a suitable machine for this
> application? I have a very small shop and a lap top would sure solve the
> space problem.

shouldn't be an issue at all, though an LCD panel may be slow to
update and you'll see a blur instead of changing numbers. newer
active panels aren't so bad.

someone mentioned earthing.... that should not be an issue, no laptop
I've used has ever been earthed through it's power supply, most having
only 2 wires going in anyway. therefore all you need to do is run an
earth wire from the sockets at the back to a good earth point. attach
your earth wire to one of the little mounting studs next to one of the
serial ports. just do a double check before you do this though, by
using a VOM between the the PSU power plug and the plug that goes into
the laptop, just to check for any solid connections. there shouldn't
be.

the biggest danger to the machine is a differnce in 'earth' levels
between the laptop and the CNC electronics when you're plugging the
thing into the parallel port. this can only happen if there's problem
in your earthing circuits in the first place.
(I've had 100 volts between a PC earth plugged into one side of a room
and a laser pritner plugged into the other side, plug em all into the
same wall socket)


steam and wind

--
David Forsyth DaForce A-T Iwr.Ru.Ac.Za
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