First test run completed. I used 600 grit powder, a little oil and a drill press, 3/8 piece of brass, into RC96 WC. I didn't drill clear through but based on the surface area of the brass and the depth it went to after a certain amount of time I figured it is removing material at a rate of .000118 cu. in/min. Based on that it would take about 4 hours to drill 3/8" through a 1/4" piece. However, I figured that if I use a copper tube I would be coring it and not have to remonve as much volume I figure it would come out to just over 2 hours to drill a half inch hole. And I could fully automate the process too (put a pipe and some weight on the quill). I'm sure there will be different results over longer periods of time given that there will be carbide powder to deal with.
I read somewhere why they use brass and copper instead of something harder. Brass is more gummy than hard so it becomes embedded with the diamonds instead of being worn off. (kind of like the new guy filling the grinding wheel full of aluminum only reversed and resulting in what you want) There was less wear on the brass than the carbide.
Just a little FYI if anyone ever wants to try some abrasive drilling. I may not be dropping the EDM just yet bet I may rig up the unused drill press and try it for a few holes.
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