On Tuesday 09 April 2019 23:40:54 Thaddeus Waldner wrote: > On Apr 9, 2019, at 10:26 PM, Gene Heskett <ghesk...@shentel.net> wrote: > > On Tuesday 09 April 2019 23:02:46 Thaddeus Waldner wrote: > >> Assuming you unplug the rotary axis when you remove it, you could > >> simply use a normally closed homing switch that unplugs with the > >> axis. Problem with this is it wouldn’t let you use the fast > >> approach, slow home sequence with a single switch. > >> > >> Thaddeus Waldner > >> Newdale School > >> Elkton, SD 57026 > >> > >> ________________________________ > >> From: andy pugh <bodge...@gmail.com> > >> Sent: Tuesday, April 9, 2019 9:34 PM > >> To: Enhanced Machine Controller (EMC) > >> Subject: Re: [Emc-users] Leaving an axis out of the home sequence > >> AND (continued:) > >> > >> On Wed, 10 Apr 2019 at 02:33, Gene Heskett <ghesk...@shentel.net> > > > > wrote: > >>> out of the logic that determines whether the machine will run > >>> gcode when that A axis has not been homed because its unplugged, > >>> off the machine and stored and either is unhomed, or was never > >>> homed since this power up. > >> > >> The simplest is probably to set it for immediate homing (home > >> search velocity zero) but have it in the homing sequence. > >> > >> If you want it to physically home when present, but not home when > >> absent, automatically, then it's harder. I imagine that some HAL > >> logic to detect presence or absence and a mux2 to switch between > >> real and simulated home (wcomp looking at apparent position of the > >> stepgen?) > > > > unplugging it isn't practical without adding a plug in the switch > > cable, but some timers could simulate that, and a mux2 to steer the > > timers or the switch could work. I'll have see if I can set > > something up along those lines. > > > > More ideas. Thanks Thaddeus. > > Another idea: > Instead of simulating a home switch with a timer, you could use an > actual home switch from a different axis (eg. z-axis). > Not sure about that one. I'll investigate the "check to use" idea first. My homes, except for A are very close to the switches, so a rehome doesn't take long. 5 seconds maybe.
One of the things I have planned for A is sharpening/shaping HSS lathe tooling, but have not found a mounted CBN wheel of a size suitable for spinning in this spindle. Seems to me the CBN people are missing a market niche by not making a fairly rigid miniature cup mounted version. The diamond wheel dremel now sells for $26, is so thin and flimsy you can't accurately maintain a face angle, plus the diamond isn't compatible with HSS, so its not a good choice for HSS. I have made an arbor to spin a 4.5" CBN cup in the G0704, and have used it a time or 7, but even though I've fine tuned the face of the arbor 2 times, it still runs out of true by several thou at the cutting face. Thats hard on the CBN. And I need to make a base wedge to hold the A nose up (or down) by 7 degrees for the clearance angles. One almost needs a 2 axis combo table for that, at which point LCNC needs a 5th axis. And that means a different interface, like a 7i90HD, or different firmware in the 5i25 to put the 5th axis on the p2 connector. The 7i76D only has 4. Humm, I supposed a software stepper could be loaded, and a base-thread setup, hal can certainly do that. 2 problems with that though, first, and show stopper being the limited Z motion available in a gantry. I bought one of those $70 touch probes, and had to make a shorter stylus to get it to clear the bed. Piece of fragile plastic junk IMO. As a probe, its usable for xy locations, but will need a round ball tip for z profiles. No where near concentric although that can be fiddled with given enough time. I'll probably get a Wild Horse probe before I'm happy. But thats a few pages down the log I'm not keeping. Simple hack-a-day carousel Tool changer first. 6 pocket probably. With this vfd, I left it running at 675 revs for a few hours yesterday, to check out the slow speed burn-up horror stories. At 675 revs, and I don't currently have any low speed boost programmed in, in 2 hours the motor was up 2C and the coolant tank was up 1C. I can stop it with two fingers, so obviously I can add some low speed boost when the new vfd gets here. It was back to running the spindle fwd yesterday. Go figure. Cheers Thaddeus, 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
