The DRV8825 drivers have issues with larger drive voltages when coupled with low inductance motors, probably like your Nema 23 ones. This shows when trying to do microstepping. High voltage and low inductance causes a biasing toward the full step positions, which leads to some 'banding' showing up in your output. Good news is if you don't use microstepping the issue seems to go away for the most part. Also, as long as you keep your drive voltage lower they will still work ok. Exceed say 19V though and the combination will start to display more artifacts. You *can* run those drivers at a suitable current to get decent performance out of the smaller Nema 23 motors. You'll just need to cool the crap out of them to run them at their full rated current of 2.2-2.4A. I personally watercooled mine, but that was probably excessive. You can set the trim pot to well higher than the max current, so don't just think you can turn it up and not measure it. Output current = 2x voltage with respect to ground measured on the pot slider. Clip a lead to your screwdriver shaft, and another to a ground pin for dead simple current setting. There is a decay setting you can alter on the module by soldering a jumper to a pin on the chip that helps, but it also makes them a lot noisier when sitting still. The real Pololu branded DRV8825 stepsticks did perform better than the knockoffs.
As for others? I replaced my DRV8825's with some AMIS-30543 chips a few weeks back. *The are not stepsticks* though and require SPI to configure them. They are a little too big and so you end up standing them on end, on an adapter board.. :) They also run just as hot as the DRV8825 chips, but do have a higher max current of 3A per phase. However, they also do not degrade when used with low inductance/high voltage like the DRV8825's do that I have seen. On Friday, May 24, 2019 at 6:42:28 PM UTC-4, Bradley Turner wrote: > > I am running a BBB with CRAMPS cape for a small 4 axis CNC. I began with > Nema 17s, however due to lack of torque I want to move up to Nema 23s. I > know that the Pololu style stepper drivers can run Nema 23s, and I wanted > to know if anyone had recommendations on stepper drivers for Nema 23s. I an > currently using DRV-8825s. > Thank you! -- website: http://www.machinekit.io blog: http://blog.machinekit.io github: https://github.com/machinekit --- You received this message because you are subscribed to the Google Groups "Machinekit" group. To unsubscribe from this group and stop receiving emails from it, send an email to machinekit+unsubscr...@googlegroups.com. Visit this group at https://groups.google.com/group/machinekit. To view this discussion on the web visit https://groups.google.com/d/msgid/machinekit/9b55b26e-fa12-4f99-ab19-71be12794d86%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
