Rich, I have looked into conventional EDM and being the cheapskate that I am, found it a little too expensive for me. I have had to get broken taps out of near completed (see expensive) die blocks before. The guy I took it to uses a hole popper. The hole popper is essentially a conventional EDM machine that used hollow brass tubes as an electrode. This got me thinking about a DIY booklet I bought some time ago that gave detailed instruction on how to build one of those hole poppers using an 100 amp arch welder as a power source. I may just have to dig up those instructions and see if that would be applicable to this. .