On Thursday 05 November 2015 20:57:10 MC Cason wrote: > On 11/05/2015 12:22 PM, Gene Heskett wrote: > > On Thursday 05 November 2015 12:39:47 andy pugh wrote: > >> On 5 November 2015 at 17:04, Gene Heskett <ghesk...@wdtv.com> wrote: > >>> Yeah, I know, a miss-cue in a contact will probably blow the > >>> driver, but ice-cubes seem pretty dependable. All this switching > >>> would of course take place with the drivers enable line off, so > >>> when it becomes enabled the relay has had time to close. > >>> Conversely, at stop time, leave it enabled for long enough to > >>> bring the motor to a solid stop, then disable, and drop the relay > >>> 100 ms later. > >>> > >>> Comments on this idea? > >> > >> Drivers suitable for a Nema11 motor are probably cheaper than the > >> relay, so this might be a false economy. > >> http://www.ebay.com/itm/1PCS-A4988-Stepper-Motor-Driver-Module-3D-P > >>rin ter-Polulu-StepStick-RAMPS-RepRap-/221921771119 > > > > Thats ok, but that driver bothers me, how about this one? > > > > <http://www.ebay.com/itm/5PCS-DRV8825-stepper-motor-driver-Module-3D > >-printer-RAMPS1-4-RepRap-StepStick-/201114247831?hash=item2ed357e297: > >g:gy8AAOSwWnFV94cl> > > > > Which seems to be a higher voltage tolerance version. > > > > But, does anyone supply a motherboard that would mount at least 5 of > > those? My google-foo seems to be broken, but if these are used in > > 3d printers, I'd certainly expect to see a method to make a whole > > bank of them useable. 4 wide, maybe even 5? > > > > Cheers, Gene Heskett > > Gene, I just built a electronic rotary table with one like one of > those, but I got it here: > https://www.pololu.com/category/154/drv8825-stepper-motor-driver-carri >ers-high-current > > I didn't think that $6.80/each in a 5 pack, was too bad, > considering what other options would've cost. It's being controlled > by a Teensy 3.2 (ARM Cortex M4), and It's controlling a NEMA 23 > Stepper, and It just barely gets warm. Current is set to 1A. > > Pololu's website has a truth table that shows how the microstepping > pins get connected. On my teensy 3.2, I have the microstepping pins > tied to 3 digital pins, so I can adjust microstepping in software. > The code is still WIP, and I'm still tying all of the individual > pieces together, but on the bench it's working nicely.
Looks like it could be socketed into 2 adjacent 16 pin dip sockets. That, for the most part, solves the "bank of them" problem. Now if I could find a suitable motor that wasn't $40/copy. Still looking on that point. Thanks. $8/copy with the header pins already soldered in seems reasonable. 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> ------------------------------------------------------------------------------ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
