[chubby hubby]

Greetings All,
As a die maker of 30+ yrs, I've worked with EDM departments for a long time. Every time I give a burn block to the EDM Dept, I need to grind off a .010 wire nub (we have another name for it, but that may get censored here) from the finished part. My finished product from the wire block is usually a punch that's burned from the wire block. So, essentially, it's a slug. The block is clamped in the wire machine, and my punch is cut out from it. Every shop I've worked at, the process has been the same. I realize there is a roughing pass, and then at least one skim cut. And this material is needed to keep the part attached to the block during the skim cut. Does anyone do this differently, or is it an inherent problem? Is there a better way to program that eliminates the need for me to grind that wire nub? I'm just looking to cut out any undo operations for those really hot jobs.... Thanks, CH.

[gabedrummin]

Unless the wire guy clamps the part and runs rough and skim passes yea your gonna have a titty to grid off .Or you could make the punch yourself .Of course that will take more time .I have never minded grinding the wire tab off .That wire machine saved me alot of form grinding time. So its a catch 22 wire a punch spend 10 minutes to grid a tab......Buy your wire guy a beer hes your friend....!

[Markced]

If your punch has a heel on it, your wire guy can program the wire path to leave the tab in that area. Then while cutting it off he can program it to step into the side of the heel a small distance like .001" to .002" then when it drops off all you have is a small burr you can stone off by hand in about 30 secs. leaving the cutoff below the surfcae of the punch.

This also works with the outer surface of a Die block or bending block. Just find an area on the component that its function is not affected by a small undercut. I have done this for 30 plus years and have eliminated alot of grind time.

[Royster]

The old fashioned way to cut a punch is to glue the part into the prep block whilst skimming off (what we call) the wire pip.

Hence the term 'glue stop' and 'slug stop'

In other words you'd rough and skim the punch leaving a portion 'tagged in'. When this is complete you'd glue the punch into place (perhaps with isopon) leaving a couple of small areas exposed including the 'tagged in' area. Whereby you need to place a power magnet across one of these other exposed areas to retain continuity. Then you can run the same rough and skims over this wire pip there by having no need to grind.

We used to do this where constant surface finish is vital but otherwise grinding a pip is minutes.

HTH