I have been doing some more reading on here and wonder whether my problems are related to the DRV8825 mixed mode decay.
In review, I have two symptoms:
1. If, in EQMOD, I try slewing at 800x I hear the stepper motors accelerating briefly then they stop and make a louder noise for as long as I hold the button down in EQMOD. When I release the button I hear the stepper motor decelerate.
2. When tracking at sidereal speed in 1/32 uStep mode I can here missed steps every second.
Reading other posts on here and articles elsewhere, symptom 2 sounds like I need to do the fast decay mod. Would symptom 1 also be expected from an unmodified DRV8825 running in 1/32 uStep mode?
My next problem is that the original blogpost that people link to explaining how to do the fast decay modification is no longer online. Please can someone explain what I need to do or point me to link that is still up and working.
Also, where can I find information on the "diode" modification in case I need to do this. Again, the links in the original posts no longer seem to be working.
Finally, would I have been better going for a stepper motor with a lower rated voltage? In my ignorance I just assumed that I should go for a 12v rated stepper. I have since seen a post on SGL where someone says that it is important to have a motor supply voltage that is much larger than the steppers rated voltage.
Thanks again,
Phil