On Friday, June 08, 2012 04:51:54 PM andy pugh did opine: > On 8 June 2012 13:30, gene heskett <[email protected]> wrote: > > Backlash comp moves in the 15 thou range are required, and that takes > > time. If the backlash comp move could be done while waiting for the > > index, it would seem to be advantageous in this case. But it is not, > > the backlash move is done after the index arrives. The synchronized > > move cannot be established until the backlash has been taken up. > > The carriage should have time to catch up before you hit the material, > though. The only situation I can think of where what you describe could > be seen is if the spindle speed is so high that the carriage simply > never catches up to the requested position. > > What does your f-error look like if you halscope it while cutting air?
I'll have to look Andy, but I suspect it will look fairly decent. I'm not out there atm. Interesting, running that metric g76 code, axis.3.f-error is a ramp to a fixed value, 20 u-volts negative when following the spindle moving left, and settles at +150 u-volts during the faster retrace move. A straight line step ramp up or down can be seen flickering thru the display. I have a feeling I am about to get better acquainted with stepgen.N.FF0, FF1 and FF2 settings I assume? Or do these also have the usual suspect inputs of a PID controller too? Dinner time, BBL. Thanks Andy. 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) My web page: <http://coyoteden.dyndns-free.com:85/gene> I may not be totally perfect, but parts of me are excellent. -- Ashleigh Brilliant ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
