[doorknob]

No, I have no experience with the Marlin firmware.

Do you have access to an oscilloscope (or to a friend who has one)? It would let you at least determine whether the firmware is actually sending step signals to the driver (and if so, what the timing of the step signal looks like).

[BooherCNC]

This seems like a common theme. I am also having the same problem. I am using the USB smooth Stepper with the C25 board and KL 8070D driver. I have home switches working, Estop working but motors skip steps. When I press the up and down key on the keyboard to move the Y axis the DRO moves approximately .750 before the motor moves. It sounds like it is running but does not turn the shaft until approximately .750 of DRO movement. I have tried steps from 400 to 2000, I have tried velocity from 20 to 400 and acceleration from 1 to 50. Not sure what the next step is and any help would be appreciated.

[BooherCNC]

Not much experience with the KL8070D. I have the steps set to default on the driver. Had it on 2000 but does not make a difference.

[jeannine]

how does one increase the voltage?