On Thursday 07 May 2020 20:53:50 Dan Henderson wrote: > I’m getting confused by the reply’s on this thread. Lol. > > Anyways, the tyco relay is rated at up to 28vdc switching voltage so > which equates to roughly 1450 rpm. I doubt I would be reversing > anywhere near that load level. I would expect the reverse would occur > at near zero rpm —assuming a G33.1 operates that way. I need to > research how that CAN cycle works within LinuxCNC? I definitely do not > want to perform any high speed reverse motion with this circuit.
g33.1 does a hard direction switch at the bottom of the hole. In the 2 machines I have with PMDC motors, I have had to insert some hal code to slow that to something the machinery can survive repeatedly. Basicly it slows the motor to a stop, detected by a timeout running out as the encoder stops, then the direction change is allowed on thru the the controller, and the speed is ramped back up in reverse. Ditto for the return to forward at the top. Sorta complex, but its all done in around 400 milliseconds per direction change on the GO704. Because the ideal waveform for that shaping is a sine-squared I am familiar with as an old analog tv engineer, and a limit3 module can do a reasonable version of that, I use that to both stop and restart the motor. Because Jons pwm-servo is a full 4 quadrant controller it pulls the energy out of the spinning motor, dumping it back into the motors psu as it stops the motor, which normally runs at 125 volts, pushing it up to about 165 volts for a few milliseconds but then dumps it back into the motor as it spins it back up in the other direction. No big power line surge despite the iron in the motor squeaking because Jon's servo amp has a 17 amp current limit programmed into it. > On Thu, May 7, 2020 at 7:41 PM James Isaac <whirl...@live.com> wrote: > > Thank you, Gene. > > > > Got it. > > Looks like I have to take the Python book from the top of the shelf, > > and put it lower. > > Firefox is my standard, so the lack of Internet Explorer is no > > hardship. Reading this Wiki puts my buying a VFD back by some > > reading time. Chuckle, you'll do it anyway :) > > Take care now, James Isaac. > > > > > > James Isaac. [...] > > Huh? Just search for rockhopper and skip the penguin results. Damn, > > that has exploded into 5 million hits since the last time I did > > that, but "rockhopper for linuxcnc" gets that page as the first hit > > in our own wiki at: > > > > <http://wiki.linuxcnc.org/cgi-bin/wiki.pl?Rockhopper_Web_Server> > > > > The are download from git, and install instructs at the bottom of > > that same page. Bookmark it recommended. 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
