Re: Completed my EDM

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Ken Stuempges"
<ozarkshermit@m...> wrote:

> I finally got some pix posted of my homebrew EDM. Let me first state
> that I am a hobbiest, retired, with entirely too much time on my
> hands. I had no need for a commercial unit. All I built it for was
> tap removal and hole punching. Actually, I never did find one of the
> $1000 eBay specials ...
>
> It works great, for my needs.
> If interested pix and some details are at:
>
> http://www.thehermitsmachineshop.com/EDM.html
>
> I was able to obtain a great amount of information from lurking on
> this site, searching past entries. Thanks to all who have posted on
> the topic of homebrew EDM.
>
> Ken

Well done !

It seems that there are few EDM's and they are far between.

One question I have is about the drill chuck and using the threads to
carry the current.

I would be leery of pasing a DC current between parts by a thread as
it seems to me that the whole electrolaysy thing might have some
transferring of metals and the threads might eventuually bugger up.

On mine, I used a piece of brass, soldered the wire to it and drilled
it like a washer so it could be bolted with direct contact to the chuck.

I don't know the pitfall of either or there is no problem either way.

On mine, I used a light bulb. Not sure if there is any difference in
operation, and not sure just how to check for that.

I did notice that it ran great for shallow holes, but as the holes
became deeper, the process slowered to a glacial crawl. I think I
lost all power to the dirty fluid and it was not directed at the
cutting tip.

One note, and this seem to not apply as your heat sinke does not get
too hot. On larger electrical devices I have seen, they mount the
fins so air can rise up over them. mounted on a side or back so as
the thing gets warm, the natural air movement allows circulation.
But, with yoru fan, it would appear you either do not generate tons of
heat, or have solved the problem.

Well done.

Dave