I'm trying to understand the power requirements. I have three nema 17 steppers that draw 2A/phase. So from my research, i would need at a minimum a 12A power supply. Other sources on the intertubes says i would only need 6A supply. I have tuned three drivers to 750mv reference so i can run my steppers at 1.5A. That was with a 12v supply. My dilima seems to be when i'm place my multimeter in between the power supply and my cnc sheild while running three steppers at the same time, i'm only draw at most 620mA from the power supply ([email protected]). My current rating barely change between the 12v supply and the 20v. Under a load, current barely changed. my current setup is an uno with grbl, cnc sheild, A4988 drivers, and nema 17 steppers. Why am I drawing 620mA of current from my supply instead of something closer to 12A when all three steppers are running? Even under a load, the current needle barely moved.