In article , Pete Keillor
wrote:

On Sat, 15 Aug 2015 17:59:24 -0700 (PDT), "
wrote:

On Saturday, August 15, 2015 at 6:00:47 PM UTC-4, Pete Keillor wrote:



I'd still need to build the carriage, stepper drive, controls, etc. I
have a Beaglebone Black which could be applied to that job. I can get
a reasonable stepper for $11 from the salvage place in town, plus some
linear bearings and a bellows coupler for not much.

Any known reasons the welder is a bad idea?

Thanks.


There are some DIY edm plans on the internet. You might look at some of
them for ideas.

Many years ago, somewhere around 1969 a friend and I kludged up a edm. We
used his drill press for the feed by setting the depth nuts and then leaned
on the handle to feed the tool a very small amount. As I remember we used a
good sized maybe 500 VA transformer and I think a voltage doubler. A light
bulb in series with the supply had low resistanece when things were working
and a higher resistance when we had the tool shorting to the work. A kludge
, but it worked and we could put square holes into tool steel.

We were charging the cap to about 300 volts. So a bunch higher voltage than
your welder would supply, but the plans on the internet all use lower
voltage.
So in answer to your qoestion , I do not know.

Dan

Thanks all. Lloyd, yeah I'm retired and I think it'd be educational,
plus I already spent an hour or two picking and pecking at it.

Good ideas, Ed. I might combine that with Dan's drill press idea for
a test. I'll try the welder at much lower voltage. If that doesn't
work, then I'll ge further into Lanlois' design using some big caps.

Make sure that no spark energy goes through the ball bearings.
Insulate the tool from the drill press, and put a short circuit between
DP chuck and DP frame.

Joe Gwinn