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DRV8825 Missing Steps


Hello currently the majority of Tevo Black Widow users have issues with missteps or salmon scaling effects using the DRV8825 stepper driver, & the solution to these issues on the forum is to upgrade the drivers to the TMC2100’s. I wanted to know if there is a solution to this issue without upgrading the drivers or adding diodes inline.
My setup is MKS Gen1.3 board w/ DRV8825 drivers, Marlin RC8 firmware, motors are Tevo 17HD40005-C5.18



Does that printer use our DRV8825 carrier boards? Clones of our DRV8825 boards are common. If you post pictures that show both sides of your boards, I should be able to tell whether they are boards we have manufactured, and might be able to help address your issues with missed steps.



Hello Nathen here are the pics


That is not one of our boards. We do not know if it is configured the same way as ours our, but you might find some of the information is this thread helpful for your troubleshooting:

The DRV8824 IC mentioned in that forum post is slightly different than the DRV8825, but a lot of the troubleshooting procedure and links in the thread should still be helpful.



Hello Nathan Thanks for the response, I’ve read thru the post & see this problem maybe associated to decay mode, I should be setting these drivers for fast decay mode? Is there a simpler way of doing this without the need to solder that specific pin on the driver chip?


We do not know how your driver board is configured, so we cannot offer any specific advice about it. You might try to contact the manufacturer.



There was a longer investigation into this issue, covered thoroughly here:

Whilst this may not be the actual Pololu DRV8825, I suspect the same discussion would apply to the general case, i.e. have the same issue as the discussion shows, which results in what has been called the ‘salmon scale effect’ which is very regular bumps in the 3D print walls, which look like salmon scales on a curved surface.
I’m suggesting putting genuine Pololu DRV8825 in, might have the same problem, and so perhaps configuration advice could still apply, if any readers can assist, greatly appreciated. Seems silly that many Black Widow owners are changing to TMS2100. The change might be redundant, if we can figure out the cause. I think our drivers are set up in dual decay mode.
Any advice welcomed.



That engineerination.com blog post you mention is referenced and linked to in the forum post I linked to earlier in this thread. There is also other information in the post I linked to (and the rest of that thread) that might be helpful for you.