[dburman]

We are using a HANSVEDT HS-1 drillman to EDM a 3 MM hole in carbide balls. We are experiencing a wear ratio of 4 to 1 a cycle time in excess of one hour to burn a depth of 1.5 inch. Any suggestion or help will be appreciated.

[bullethead67]

Just a guess but mabye it has something to do with the spherical shape of the workpiece. Im not an EDM guy but I would take a mini vice and EDM a sphere almost halfway into each jaw face that was the same diameter. Clamp a ball in and do a few test burns. I may be completely wron but I read somewhere that electricity will gather on corners and points of objects to discharge. Not a lot of corners or points in a sphere. Clamping with a high percentage of the workpiece surface would effectively change the shape of the workpiece.

I dont know if it would be practical to shutdown a shop to do a test Im just saying what I would try first. Or mabye its a power supply issue.

[bullethead67]

Just read up on the machine you have. the 3mm hole is just barely above your machines maximum. mabye try switching to a different dielectric. I read your machine uses ordinary tap water. mabye you can try cleaning the tank and using distilled water. Check your machines documentation to see if it is possible to use something else. like oil