On Sun, 6 Jun 2010, Gene Heskett wrote: > Date: Sun, 6 Jun 2010 21:18:52 -0400 > From: Gene Heskett <gene.hesk...@gmail.com> > Reply-To: "Enhanced Machine Controller (EMC)" > <emc-users@lists.sourceforge.net> > To: "Enhanced Machine Controller (EMC)" <emc-users@lists.sourceforge.net> > Subject: Re: [Emc-users] Detecting limits without switches > > On Sunday 06 June 2010, Neil Baylis wrote: >Just wanted to point out that there are millions of inkjet printers and >plotters in operation right now that use this exact technique.
-And I would point out that those are 100% steppers, driving the carriage by -toothed belts with solid plastic stops at the end of the carriage travel. -They would have no problem backing away from such a stop as there is zero -chance of binding the drive screw. Not to mention that those are generally -mouse powered steppers, with only 1-2% of the power available that we use as -a matter of fact. Umm, not any more, all the inkjets I've seen are really cheap servo systems (battery toy type motors and a linear mylar strip encoder) I think homing against a stop is OK with a torque controlled system (move slow and limit torque when homing) If your encoder has an index then this would give an accurate home. Of course without limit switches, theres nothing to stop such a system from slamming into the stop at full torque with drive or software error.. Peter Wallace ------------------------------------------------------------------------------ ThinkGeek and WIRED's GeekDad team up for the Ultimate GeekDad Father's Day Giveaway. ONE MASSIVE PRIZE to the lucky parental unit. See the prize list and enter to win: http://p.sf.net/sfu/thinkgeek-promo _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
