On Tuesday 22 October 2019 19:26:07 Gene Heskett wrote: > On Tuesday 22 October 2019 17:17:09 andy pugh wrote: > > On Tue, 22 Oct 2019 at 21:47, Gene Heskett <[email protected]> > > wrote: > > > > Steppers are good for driving things slowly. What are you > > > > pumping? > > > > > > Koolmist to a misting nozzle. Pretty close to plain water.= > > > > That sounds like a dosing rather than pumping application, so I > > would definitely be looking at steppers. > > Unforch, the pumps motor is a 12 volt brushed pmdc motor. And while I > have a quartet of tb6550's I took out of the 6040 because they, and > the psu were way too puny. So the pwm seems the best choice. And its > 10% of the size of any stepper motor I have. Weight is maybe 2oz, so > it can ride the z carriage if it had to but I'm considering changing > that motor for one with 4x the muscle due to the weight of the 1hp > spindle motor it has to lift, making 30 ipm the best it can do running > up the pole, where xy can do 200 ipm with 28 volts feeding 2M542 > drivers. > > But I'll likely put this in a hose clamp near the bottle, which moves > with the gantry's y motion. Separate project from changing the z > motor. So it looks like a single mosfet and a free wheeling diode to > protect the mosfet. I can drive it direct from a cmos rail to rail > logic signal. I'm amazed I can't buy that on fleabay. For a $10 bill > for a 5 pack. Litterally a relay driver. And I may have found one, 4 > channel, so I sent the vendor a couple questions. > > Cheers, Gene Heskett
And after that, with absolutely zero thanks to fleabays busted search functions, I stumbled over the exact thing I was looking for, 7 bucks a pair. Can handle 5 amps with an added heat sink, at up to 40 volts. Turn it on with a solid 5 volts from the 7i76, and it shouldn't even need the heat sink. Shipped from Kansas, I should have them Monday. This motor isn't that hungry anyway. 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) If we desire respect for the law, we must first make the law respectable. - Louis D. Brandeis Genes Web page <http://geneslinuxbox.net:6309/gene> _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
