Hi Gene, On Aug 20, 2007, at 11:19 PM, Gene Heskett wrote: > On Tuesday 21 August 2007, Jon Elson wrote: >> Gene Heskett wrote: >>> Understood. In playing tonight with 25 volts & probably 100 ma >>> average, I >>> found that spinning the electrode at around 1k rpms seemed to add >>> enough >>> agitation to the oil that I could use it all up and go about 30 thou >>> before I had to vacuum it out and refresh it, with about 1/2 cc in a >>> modeling clay dam around the hole. A 100 rpm spin would short in >>> just a >>> thou or two. >> >> That is way too low a current for any serious metal removal. >> You want at least an amp, and it will still be really slow. You >> need an insanely fine feed. I have .000025" per encoder count >> on the Z axis of my mill, so I could get a pretty slow feed, >> about .0001" every second. It still took all evening to burn >> out one tap. I think with a hollow electrode with a drip feed >> scheme through the electrode it would go a lot faster. > > Theres always that 'yabut' Jon, in this case yabut where can I find > one of > those? :)
I always thought 'yabuts' were those things with long ears. :-) Try your local or not so local Model Airplane shop. The typically have multiple sizes of brass tubing that just slip inside each other. The fancy stuff with internal structure is available off the web. IV tubing should work for dielectric delivery if it doesn't curl up and die from the solvent. Being able to flush a cavity in EDM is VERY important. Not much else will do as much for erosion speed. Real edm systems also filter ( 5 um ) and reuse the dielectric. For the small amounts you use it is probably a throw away. > >> The alum-tap is a really light fluid, maybe just a little higher >> viscosity that water. It worked MUCH better than #20 oil, which >> I also tried. Try a couple different fluids to see what works >> best, it makes a big difference. > > I have some other stuff too besides the fuel oil (#1 I think), > paint thinners > etc could be tried too. Aluma-tap would be a foreign language here > in WV > unless I ordered it from someplace I suspect... I just checked my lamp oil container: "Lamplight" ultra-pure, Menomonee Falls, WI > > Q? Does distilled water carbon up like the hydrocarbons do when > doing this? Nope, no carbon there to muck up; just hydrogen and oxygen. > > I ordered a pair of those transformers I posted the link to a bit > ago, so I > can go as high as 6 amps short circuit with around 77 volts peak open > circuit. But I can't find any suitable electro's for filtering > though. > Other than making the sizzle buzz a bit, is upstream filtering of any > advantage? My discharge cap is a 10 uf, 1.5kv rated square can, > presumably > oil filled. Even at this voltage, if exposed it will spit > sparklers 2". > > I was having emc lower the electrode at about .0012"/min. > Steppers, had to > look very close to see it moving at all. My z divider is 16,000, a > wee bit > coarser than yours, but the real speeds are similar. Dave > > Thanks. > > -- > Cheers, Gene > "There are four boxes to be used in defense of liberty: > soap, ballot, jury, and ammo. Please use in that order." > -Ed Howdershelt (Author) > Yo-yo operating system = WinNT: it goes up..., it goes down..., it > goes... > > -- From a Slashdot.org post > > ---------------------------------------------------------------------- > --- > This SF.net email is sponsored by: Splunk Inc. > Still grepping through log files to find problems? Stop. > Now Search log events and configuration files using AJAX and a > browser. > Download your FREE copy of Splunk now >> http://get.splunk.com/ > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
