Hi, Im building my own delta 3D printer and I’m having issues with the DRV8825 that controls the nema23 placed in the sliders. First, some hits to put you in situation:
-Arduino mega/RAMPS 1.4 based system with Marlin Firmware (latest version).
-Nema23 set at 2A (current according to the datasheet)
-DRV8825 calibrated at 1V, so 2A in the output.
-Running at 30mm/s
-12V PSU
-1/32 ustepping (I think this could be a potential solution, should I full-step?)
That’s the main information related to what I have, but also I have discovered some things that could help you.
-Skips steps at same angle of the motor. At first sight I thought it was a friction problem but wasn’t, even before lubricate everything and take out the motors, still skipping steps.
-I have the feeling that when skips steps the motor doesn’t have torque at all, actually I can move the slider “freely” till goes up enough (and out of that angle that skip steps) and then works fine.
-I have read many many posts and I suspect about the low speed (DRV8825’s at low speeds and low currets dont work nice) so ill try to increase the speed to see what happens.
-With manual control, I can go over the critical zone and doesn’t skip steps (obviously, travel speed with no extrusion is bigger than printing speed)
-Haven’t tried that antiparalel diode solution that can be found in (http://www.engineerination.com/2015/02/drv8825-missing-steps.html) But don’t think will be a solution, i really have the feeling that has a huge loose of current.
-Have checked lots of DRV8825 so is not a bad driver.
-I have many suspects that has to be the driver because is a cyclic problem, also I have changed 2 times the arduino/ramps and happens the same. Some signal in the output could be the issue.
-The problem appears in two of the three motors but, if I change the drivers, the issue is now in the motor connected to the driver.
After googleing and reading lot of forums and posts, I don’t know what can I do. I hope All the info above helps to put you in situation.
Thanks in advance.