Re: Tap burning EDM? Need it Quick and Dirty ;-)

Hi John,

I have been following this thread with some interest.

First question is why the heck were you using a spiral tap in steel ?

second, let us know how it worked and what you did for liquid.

I am still ammassing the needed components, the EDM is on my wish
list for some far off time when I have no project or am in great
need. And for those, I keep my eye out for the parts I need at
greatly reduced prices.

I also put this off for the spinning head part. Never thought of the
vibrator style. seems that is so much easier to implement than
rotating.

If you can, please post or send pics.

Dave

--- In CAD_CAM_EDM_DRO@y..., "jmkasunich" <jmkasunich@y...> wrote:
>
>
> Turn, Turn, Snap... Arrgh!
>
> Busted an 8/32 spiral flute tap in a piece of A2 tool steel
> last night. I want to try the EDM approach to get it out.
>
> I checked out Jon Elson's EDM page at
> http://pico-systems.com/edm.html
>
> The electrical side is no problem, I've got a 48V 10A
> unregulated DC supply (for my CNC shoptask project), and
> a Variac, and enough other parts to make the sparker.
> I've got enough electrical knowledge to avoid shocking
> myself or frying something.
>
> The electrode holder is no problem, I can cook up something
> simular to Jon's. The problem is the electrode feed. Jon
> used his CNC mill to spin and advance the electrode. I don't
> have a CNC mill (yet). I have a drill press that will go
> slow but doesn't have a fine feed. I have the Shoptask mill,
> which has a moderately fine vertical feed, but won't go slow.
> I could also use the Shoptask lathe function, feed is better,
> but I don't know how to keep the fluid around a horizontal
> electrode. I could also try to build something specifically
> for this job - a piece of 4-40 threaded rod would give a finer
> feed than any of my machines, but gets away from the "quick
> and dirty" approach. I don't want to spend several days
> getting this tap out.
>
> It seems that anything simple that I can come up with will
> require manual electrode feed. Is it practical to use
> manual feed to burn out about 3/8" of a #8 tap? Or is slow,
> smooth advance of the electrode too difficult to do?
>
> Any suggestiuons?
>
> Thanks in advance,
>
> John Kasunich