On Wednesday 02 March 2016 23:53:36 TJoseph Powderly wrote: > sorry Pete > I disagree, any time spent in the wrong position is time spent making > bad discharges > which can damage surface by overheating > or > spend time throwing snowballs that fall short of hitting the target > imo, update postion as fast as possible > the average velocity ( a RESULT) will be low > but the process will be more stabile and the surface will not be hard > and crusty > abd the time will be lower > oops power fail in ChiangMai > ttyl8r > tomp
One thing I have always felt needed to be asked, but don't recall seeing it discussed, is when doing a sinker edm to imprint a carbon mold like I've seen pix of, like engraving a relieved signature, is there an optimum current per square, either in cm2 or in2 to design the process to so it functions best? And in terms of wear on the shaped carbon electrode, is there a best current per square in terms of the metal removed vs the carbon wasted that will prolong the electrode life vs metal removed? I've seen other processes where optimizing one is not optimizing the other. Or is there a better material to make the electrode from? > On 03/02/2016 10:05 PM, Pete_Gruendeman wrote: > > Hi Nicklas: > > Correct that looping once per millisecond is definitely fast > > enough. On my machine, 40,000 encoder counts = 1 inch. Spark > > lengths, even for finishing operations are 0.001" or longer, or 40 > > encoder counts to go from first spark to the electrode making > > physical contact and that's in 1/25th of a second. That's not a > > problem if the machine is moving at 2- 4 inches per minute. At 4 > > IPM, coming to a stop in 0.001 inches requires an acceleration of > > -0.01852 feet per second squared or -0.00058 g's of acceleration. > > No problem. > > > > The other axes would be the same in that gap voltage/current > > measurement at 1,000 times per second is plenty fast enough. In > > fact, the program I wrote upon detection of gap voltage too low > > waits on location for 10 milliseconds and then checks again as often > > the situation of the electrode being too close clears itself in that > > much time. I didn't differentiate between gap voltage being too low > > and it being zero (physical contact). If I did, then the signal to > > back out should have been given without any delay. > > > > Pete Gruendeman > > > > -------------------------------------------- > > On Wed, 3/2/16, Nicklas Karlsson <[email protected]> > > wrote: > > > > Subject: Re: [Emc-developers] EDM gap control (Control parameters) > > To: "Pete_Gruendeman" <[email protected]>, "EMC developers" > > <[email protected]> Date: Wednesday, March 2, > > 2016, 4:12 AM > > > > > ... > > > All of this start, stop, backup motion > > > > will result in an average rate of travel that is on the > > order of inches per hour. It's not fast. Though the > > positioning rate for forward and reverse motion can be > > inches per minute. > > > > > ... > > > > Then it is so slow as at > > maximum inches per minute there is no point with > > position/velocity loop faster than once each millisecond? > > > > For Z-axis there would be no > > problem with 40kHz servo loop if needed. > > > > Regards Nicklas Karlsson > > > > -------------------------------------------------------------------- > >---------- Site24x7 APM Insight: Get Deep Visibility into Application > > Performance APM + Mobile APM + RUM: Monitor 3 App instances at just > > $35/Month Monitor end-to-end web transactions and take corrective > > actions now Troubleshoot faster and improve end-user experience. > > Signup Now! > > http://pubads.g.doubleclick.net/gampad/clk?id=272487151&iu=/4140 > > _______________________________________________ > > Emc-developers mailing list > > [email protected] > > https://lists.sourceforge.net/lists/listinfo/emc-developers > > ---------------------------------------------------------------------- >-------- Site24x7 APM Insight: Get Deep Visibility into Application > Performance APM + Mobile APM + RUM: Monitor 3 App instances at just > $35/Month Monitor end-to-end web transactions and take corrective > actions now Troubleshoot faster and improve end-user experience. > Signup Now! > http://pubads.g.doubleclick.net/gampad/clk?id=272487151&iu=/4140 > _______________________________________________ > Emc-developers mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-developers 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) Genes Web page <http://geneslinuxbox.net:6309/gene> ------------------------------------------------------------------------------ Site24x7 APM Insight: Get Deep Visibility into Application Performance APM + Mobile APM + RUM: Monitor 3 App instances at just $35/Month Monitor end-to-end web transactions and take corrective actions now Troubleshoot faster and improve end-user experience. Signup Now! http://pubads.g.doubleclick.net/gampad/clk?id=272487151&iu=/4140 _______________________________________________ Emc-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-developers
