On Tuesday 26 March 2019 10:55:45 Peter C. Wallace wrote: > On Tue, 26 Mar 2019, Gene Heskett wrote: > > Date: Tue, 26 Mar 2019 08:03:17 -0400 > > From: Gene Heskett <ghesk...@shentel.net> > > Reply-To: "Enhanced Machine Controller (EMC)" > > <emc-users@lists.sourceforge.net> > > To: emc-users@lists.sourceforge.net > > Subject: Re: [Emc-users] Rock64 pre-orders on Banggood. > > > > On Tuesday 26 March 2019 07:19:19 andy pugh wrote: > >> On Tue, 26 Mar 2019 at 06:35, Chris Albertson > > > > <albertson.ch...@gmail.com> wrote: > >>> The loops do need data. They need a target position or a target > >>> velocity. These targets are sent across an SPI (or I2C or Ethernet > >>> or,..) interface from a Linux machine. But you MUST de-couple the > >>> timing. Linux can not be feeding one target number at a time. > >> > >> Drawing the boundary becomes more difficult when you add in > >> probing, threading and spindle-synchronised motion. > > > > And it appears I may have to put a C1G rev4 back in service just for > > limit and home switches, the 7i76 takes too long to recognize a > > closed home switch. > > I dont think this is true, motion only samples the home switches at > the servo thread rate so there is no speed advantage of sampling the > inputs at the base thread. > > How wide is the home switch pulse at 120 degrees/sec? > less than 1 ms seems unlikely... > I see it about half the time in a halmeter at 360/sec degrees as it flies on by without a stutter. At 120/sec it stops on top of the cam, running slow I'd guess 4 degrees wide. but haven't actually measured it.
Could be narrower. Its working now, which is the bottom line. My next experiment is to see if some glue covered elastomer is sufficient to stop from smashing these switches flatter than a Coors can at a usable homing speed. Theres far under a 0.5mm of motion between touching the switch and smashing it where I want to put the switches. So we'll have to play with home_search_vel's for all the linear axis's to make sure it can stop in time. But now I'm stuck, waiting on Amazon to get me some wiring loom big enough to take the 2 additional 3/16" cables to the switches. What came with the mill just don't have room. I just this morning replaced the 2nd cable chain because there was no room left in them. I used everything putting the mister air line in the one across the top of the gantry. 2 less motor cables it it. No room for home or limit cables so change it for a wider chain too. Some day. I hope to actually carve something on this... Thanks Peter. 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> _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
