On Tuesday 30 July 2019 23:52:23 TJoseph Powderly wrote: > you ask for long lasting > that would be tungsten carbide > but > i suggest using easy to manufacture, easy to find, low cost > because it will wear anyway > > so copper, with little lead ( often copper sold will be 'machineable' > which means lead which means higher wear ) > > for a key way you should be able to mill machine the electrodes > and use the largest face ( dont cut with small end of rectangular > prism , cut with side ) > ( do the hokey pokey - put your big foot out i used to teach the > operators ) > use LOTS of pecking, just get a sizzle and jump away > > you dont have real edm equipment, just a hack so you gotta play safe > > and set it up vertical and submerged if possible so the jump opens up > to a flood of the submerged fluid > pee down the cut from above and to the side, you want to see the black > puff out each jump > > Negative polarity ( tool neg, work pos ) If you use an r/c pulse > generator then always negative tool. > Short ontimes and hi freq ( say 10to50uS on and 200 or more off , 2000 > is good for lash-up ) > > The exaggerated offtimes aid in letting the dielectric recuperate to > non conductive state. > The short cut times ( jump cycle ) aid in poor gap control, you > actually cut while ' in the zome' > but your system cant maintain the zone > So you get efficiency by 'drive by edm', you go thru the zone each > jump pass and get a little work done. > You jump away right away and reduce the heat build up ( because you > likely crashed into the work and shorted ) > > you're a scope kinda guy, try this... > reduce the gap using a resistor divider giving max 5v and watch the > process when you get more 'chairs' then you are cutting more > when you flat line, you're crashing > when its open voltage all the time you're missing > ( old elox guys look for 'grass' like on a lawn , > there was a scope on all old elox generators, > the 'grass' was due to slow scope ) > > hth > tomp > Got it all hooked up, expected lots of noise because the capacitor was 10 uf. Note the /was/. From the symptons, taint no more, so while I am getting some fire, its dead silent! So I don't think that cap is a cap any more.. Fleabay, & see if I can find another. Big cap, around 64 cubic inches, only 70 years old.
So I sat down to write a while loop, using Big John's arcgenm18.py. and haven't managed to get loadable code yet because I think I need the G18 plane where y can be left out as the g2 nor g3 moves the y. But the output of arcgenm18.py is assumeing G17. not G18. So I need to translate the ijk into what it would be for G18 motion. Is there a rule of thumb for that? > On Wed, Jul 31, 2019 at 9:17 AM Gene Heskett <ghesk...@shentel.net> wrote: > > Greetings all; > > > > Like Jon said on the sheldon list. woodruff keys cut into a case > > hardened shaft are a bear. Carbide makes a mark, for about 5 > > seconds. > > > > So it appears I will have to dig the keyways by EDM. > > > > Because the electrode will go away too, what makes the longest > > lasting electrode material? > > > > And which polarity, if it makes a difference? > > > > Thanks all; > > > > Cheers, Gene Heskett > > -- > > "There are four boxes to be used in defense of liberty: > > soap, ballot, jury, and ammo. Please use in that order." > > -Ed Howdershelt (Author) > > If we desire respect for the law, we must first make the law > > respectable. - Louis D. Brandeis > > Genes Web page <http://geneslinuxbox.net:6309/gene> > > > > > > _______________________________________________ > > 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 Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) If we desire respect for the law, we must first make the law respectable. - Louis D. Brandeis Genes Web page <http://geneslinuxbox.net:6309/gene> _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
