my controller uses A3979 driver chips, set to x and z - 1.4A, y and a - 1.8A by resistors. it uses 30v supply and drives nema 17s. I would like more torque? I want to extend the y from 840mm to 1000mm to allow vertical milling and a rotating axis. I like the c-beam designs, and the all in one linear actuators, with cbeam, lead screw, plates and nema 23s. I would like to go that route when upgrading. My thought; the a axis is an optional driver. Its connector can drive two larger current pwbs from these outputs and power the new y axis motors. Additionally I can add a higher voltage (48?) supply to these drivers. Can I run 2 steppers from say a 7A driver, or are 2 separate drivers preferred? Question: is there anyway to use the outputs to the motors from the A3979s to drive an additional higher output h-bridge. My controller works well, it's just under powered. I'm thinking of it as a preamp. All the signal shapes are correct, so just amplify them? Power these new h-bridges with the new 48v as well and voila I can drive bigger motors.