Post by thread:[OT]: Erosion cutting, was Argh! (feel free to ign

>There's even a fellow in the Windsor ON area (member of the >Detroit metalworking club) who has made one from scratch himself. >Mr. Robert Langlois, if I got the spelling right. You don't happen to know if there is a web page, do you? This sounds like an interesting way of doing things. I knew about the application for making moulds for plastic moulding, but not for cutting, always assumed lasers were used for this (but the one material they apparently have problems with is Aluminium.) Another item used for the electrode in spark erosion is carbon. We had some moulds done like this a good few years ago now, and it produced a very nice "orange peel" finish on the plastic from the erosion pattern on the mould. -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

At 04:56 PM 8/2/02 +0100, you wrote: > >There's even a fellow in the Windsor ON area (member of the > >Detroit metalworking club) who has made one from scratch himself. > >Mr. Robert Langlois, if I got the spelling right. > >You don't happen to know if there is a web page, do you? This sounds like an >interesting way of doing things. Here are some pictures of his demo: http://www.pacificsun.ca/robert/www/2001/part05.htm (oh, he actually lives in Guelph, not Windsor ON, my bad) Robert has given a talk on(and shown) his wire EDM the last couple of years at N.A.M.E.S., held in Wyandotte MI and now Southgate MI (just south of Detroit) each spring. So far I have not seen a write-up on the wire-cut machine but you can buy a magazine with instructions on building a stepper-driven sinker EDM for something like $19 USD. >I knew about the application for making moulds for plastic moulding, but not >for cutting, always assumed lasers were used for this (but the one material >they apparently have problems with is Aluminium.) Yes, but there are other methods like abrasive / water cutting that might work on thin aluminum. I typically specify CNC punching for my company's products. For steel plasma cutting works okay if you need only a rough outline. The wire EDM cuts really accurately, arbitrarily complex outlines and cost is not unreasonable for tools (too slow and expensive for most production parts, though I did see one medical part being made in production) (and being EDM hardness of the material is a non-issue). Another thing you can do is tilt the wire slightly and form both sides of a punch die with the proper clearances out of a single piece of metal. A bit of welding has to be done to clean up the hole to start the wire, IIRC. >Another item used for the electrode in spark erosion is carbon. We had some >moulds done like this a good few years ago now, and it produced a very nice >"orange peel" finish on the plastic from the erosion pattern on the mould. Yes, a fine form of graphite. It's nice if the as-machined finish is okay, saves polishing (time consuming work and thus expensive) and texturing (which the mold shops often have to send out). That would be interesting to see. Best regards, Spehro Pefhany --"it's the network..." "The Journey is the reward" spam_OUTspeffTakeThisOuTinterlog.com Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com 9/11 United we Stand -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.