On Sunday 04 March 2018 20:22:47 Chris Albertson wrote: > On Sun, Feb 18, 2018 at 2:10 PM, Gene Heskett <ghesk...@shentel.net> wrote: > > On Friday 16 February 2018 06:16:00 Chris Albertson wrote: > > > > > > That I have figured out finally Chris, its moving close to 100 ipm > > with a 32 to 42 pulley set in the z on my Sheldon but its noisy as > > can be in the 7 to 20 ipm box. Its noise telegraphs up the keyboard > > shelf mounted on its mounting bracket. I'd had to put a 1/4" high > > fence around the edge to keep other stuff from vibrating off > > including the keyboard itself. Its also running an a few more volts > > than it was on the mill with its heavy head. 7 more volts IIRC. X is > > slow, but if I ever get off my duff and make a thin vibration > > damper, I think that would bring it up to 60 ipm. Its a nema 24, 8 > > wire, wired parallel and getting all a 2m542 can give it at around > > 43 volts. Neither motor is best match, but what I had, or could get > > in the crowded area behind the new apron. > > Seem like you machine runs into some form of resonance at 7 to 20 ipm. > I'd like to see a controllers that can be reconfigured in real time.
So would I, but that would also involve some magic at the transition point else it would slip at a fractional step without first placing the motor in its 0 phase position. And that would need to be done synchronously in lcnc at the same zero phase point. > for low speeds you might use 1/8 steps them move to /14/ and full > steps at higher RPM. It could be built. But simply going to a > digital drive might be enough. > > I also have an M542. One of the things I want to do is compare it > with an A/B test to a DM542. The newer one with e "D" is digital and > the manufacturer claims a significant reduction in noise and > vibration. They cost about the same. (I'm making a test jig for > another project where I measure the strength of 3D printed plastic > gears. It will use the same motor size.) Most, but not all, are 2M542's now a decade old. The only diff I've noted is the dip switch positions to get a common speed. /8 or /16 but /16 is generally too fast for the opto's. Buying more as the need arises, I probably have at least 3 versions in service now. And once programmed, they Just Work(TM). > > I also want to try one of their new "closed loop" motors which > people on you tube have demoed. Those are even better running but > cost about 60% more. I can do this because I need to buy more > motors, quite a few more as the thing I'm using the mill and lathe and > printer for also uses motors. > > I did some more calculations again, The static load of a milling head > on one vertical dovetail means that power is required even when moving > downward slowly. In theory if there were no friction we should be > able to generate power by letting the head fall down which would spin > an electric motor With a vertical acme screw more then half the motor > power goes into overcoming friction. > > In a few months I expect to have real data on vertical ball screw > performance and also onplatic gear strength and the three types of > stepper motor drivers. Maybe longer because client are calling be > more now, work seems to be picking. Darn. -- 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> ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
