HI Andy, There's also this. https://www.cnczone.com/forums/general-edm-discussion/ Many links are broken though. And the Yahoo group on EDM is gone and it doesn't look like it was migrated to groups.io.
John Dammeyer > -----Original Message----- > From: andy pugh [mailto:bodge...@gmail.com] > Sent: January-31-21 5:28 AM > To: Enhanced Machine Controller (EMC) > Subject: [Emc-users] EDM from scratch > > I have started to play around with EDM. The intention is to make an > EDM "grinder" to profile tool steel and possibly carbide cutting tools > using CNC-turned profiles. > > At the moment I am using a cobbled-together XY table with a couple of > STMBL drives. > One of the STMBL analogue inputs is used to measure the current > through the gap. (ie using the voltage across the resistor that a > capacitor is charged through). > Then a PID controller tries to achieve a target current by adjusting > the adaptive feed pin. > > I think that it shows promise, but only partly works. > > I am using a 50R resistor and a 1000uF capacitor. I suspect that this > is too high on both counts. > I am working at 40V and it seems that the tool welds to the work too readily. > > I suspect that I would get different results if I controlled to the > gap voltage, rather than charging resistor voltage. And probably > better still with some sort of signal processing on that voltage. > > What combination of R, C and V would be typical for a servo-controlled > eroder? I imagine it might be different to a "doorbell" style one. > > Current set up: https://youtu.be/nxpmEFnmK-A > > -- > atp > "A motorcycle is a bicycle with a pandemonium attachment and is > designed for the especial use of mechanical geniuses, daredevils and > lunatics." > � George Fitch, Atlanta Constitution Newspaper, 1912 > > > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
