On Saturday 01 May 2021 08:35:12 Thaddeus Waldner wrote: > So these are actual stepper motors and not 3-phase BLDC motors with > step/direction input?
yes, and while I said a step loss will stop them it has to exist for an unspecified time frame. You can fasten them down, put a vice grip on the shaft and turn them 1/4 turn before they error, they will resist mightily and if you let go of the vice grips quick enough, they'll catch up to a zero error and just keep on trucking. I can, creeping along with my jog dials, run a carbide tipped tool into a stationary chuck jaw, and when its found itself jammed, it shuts down the output drivers and bounces about 10 thou clear of the chuck, all without damageing the chip in the tool. The machine will obviously need re-homed as I have the volatile option set in the .ini file. Thats a 25mm z screw, but my x screw is only an 8mm, so while its wired I've deferred to the size of the screw and the possibility of damaging it, and not tested it similarly with its shorter, 2NM rated motor. That screw today seems to be made of pure unobtainium, its half of one of a triplet I bought from Stuart St. about 15 or more years ago to cnc the smallest hf mill. > I always assumed that it’s the latter, with the difference being lost > in translation. So did I, but installing one, replacing a stepper that ran burn you hand hot, and finding it stone cold after half an hour powered up but the only move was homing the axis was quite the eye opener, the motors holding current is determined by the encoder error. No error=not enough holding currant to make feelable heat. You think its shut down, until you try to turn it... [...] 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
