On 5 Jul 2014, at 13:54, John Alexander Stewart wrote: > Hi all; Hope this question is considered on-topic, or at least not too far > off. > > I'm doing another CNC conversion - my largest yet. G0704 (BF20) style mill, > and I'm wondering about stepper drivers. (Have a Mesa 5i25/7i76 combo; > maybe my next machine will be servo) > > I'm wondering about drivers - I have as spares a Gecko G540, some 48v 7.5a > switching power supplies, a couple Gecko 3.5A drivers (the ones in the > G540, but standalone) but wondering: > > 1) digital drivers, eg automationtechnologiesinc.com ones, are they worth > the price? > > 2) China drivers look the same as 1); presumably the technology is the > same, just name-badging; > > 3) Europeans seem to use smaller steppers than North Americans; is there > much savings (e.g., power, heat) from using smaller steppers? I'd guess so. > Not necessarily. I'm using 600NM NEMA 34 triple stack steppers, with Gecko 201s running at 78volts. PSU is based on two toroidal transformers, giving up to 10A at 80v for up to 4 steppers. Over current and over voltage protection, with soft start - overkill really. That size of stepper can each provide the equivalent of 1/4 horsepower, if my rough calculations are correct. That should be enough for a mill up to the size of a Bridgeport. I just don't believe in trying to trim the size or power of a stepper to save a few pounds/dollars. I'd rather over-spec slightly in the knowledge that I have power in hand.
Marcus > I'm in Canada, so shipping from the USA or China or Europe is about the > same - expensive - so source location is not an issue. > > It does seem a shame to purchase new drivers and power supplies, but I > might as well do this machine "right". > > Thanks for any insights you might give. > > John A. Stewart. > ------------------------------------------------------------------------------ > Open source business process management suite built on Java and Eclipse > Turn processes into business applications with Bonita BPM Community Edition > Quickly connect people, data, and systems into organized workflows > Winner of BOSSIE, CODIE, OW2 and Gartner awards > http://p.sf.net/sfu/Bonitasoft > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users ------------------------------------------------------------------------------ Open source business process management suite built on Java and Eclipse Turn processes into business applications with Bonita BPM Community Edition Quickly connect people, data, and systems into organized workflows Winner of BOSSIE, CODIE, OW2 and Gartner awards http://p.sf.net/sfu/Bonitasoft _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
