On Thursday 25 March 2010, Mark Wendt (Contractor) wrote: >At 08:43 AM 3/25/2010, you wrote: >>Mark Wendt (Contractor) pravi: >> > At >> > .001, sometimes I'd get no movement (I'd here stepper motor noise but >> > no movement on the dial indicator), other times I'd get a half-thou, >> >>This can be only mechanical then... Check backlash and endplay of nut... >>check coupler too.. If motor make step and gantry not then don't blew >>software :D >> >>Slavko. > >This is on a rack and pinion system, pulley mounted directly on >stepper, pinion has pulley mounted directly to it, with cogged timing >belt driving the pinion. All these numbers were with the gantry >moving in one direction, jog and hold, jog and hold, while watching >the dial indicator for movement between jogs, which there was >none. Does backlash come into play when all moves are in the same > direction? > >Mark
Ahh so. I found when I was tuning up my new z axis drive which uses a gilmer belt with a 17 to 42 ratio, that it had to be _very_ taut, any visible amount of slack on the slack side of the movement and the detected backlash was very inconsistent. That belt has got to be tightly stretched. Even a year+ later, I'd imagine the tension is at least 25 pounds. That left me with about .0036" to put into the backlash setting, the lowest amount on that cheap HF mill. I could get better but the sled also tips on the post a few arcseconds if the gibs are loose enough to move it. Tight gibs, by raising the drag, actually make the tipping moment worse. Someday I have got to get a decent mill... > >--------------------------------------------------------------------------- >--- Download Intel® Parallel Studio Eval >Try the new software tools for yourself. Speed compiling, find bugs >proactively, and fine-tune applications for parallel performance. >See why Intel Parallel Studio got high marks during beta. >http://p.sf.net/sfu/intel-sw-dev >_______________________________________________ >Emc-users mailing list >[email protected] >https://lists.sourceforge.net/lists/listinfo/emc-users > -- Cheers, Gene "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) VMS version 2.0 ==> ------------------------------------------------------------------------------ Download Intel® Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
