Okay, update on the troubleshooting for this problem. First, some info:
1) The motors and wiring on this printer (Mendel90 config) have worked with a Sanguinololu 12V system previously.
2) The motors and wiring have never been tried with a RUMBA configured with 12V instead of 24V.
Given #2, I swapped out power supplies to see if 12V has the same behavior. It does - which means to me it has nothing to do with voltage, and make be a wiring issue (like many of these symptoms indicate).
I will also check the Marlin firmware configuration.h file to determine if the right board is selected.
Before I checked this, I did check current limiting Vref on the A4988s, and they all read 0.8v - which (x2.5) equates to a 2A current limit on each. Seems okay, but let me know if you disagree.
Thanks!
Rob
1) The motors and wiring on this printer (Mendel90 config) have worked with a Sanguinololu 12V system previously.
2) The motors and wiring have never been tried with a RUMBA configured with 12V instead of 24V.
Given #2, I swapped out power supplies to see if 12V has the same behavior. It does - which means to me it has nothing to do with voltage, and make be a wiring issue (like many of these symptoms indicate).
I will also check the Marlin firmware configuration.h file to determine if the right board is selected.
Before I checked this, I did check current limiting Vref on the A4988s, and they all read 0.8v - which (x2.5) equates to a 2A current limit on each. Seems okay, but let me know if you disagree.
Thanks!
Rob