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-Prin >> 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-carriers-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. -- MC Cason Eagle3D - Created by Matthias Weißer github.com/mcason/Eagle3D ------------------------------------------------------------------------------ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
