Stepper Drivers

The printer uses various stepper motor drivers. This is because the ones included with the BTT Octopus board are not powerful enough to drive the NEMA 23 motors used for the X, Y, and Z axes. NOTE: Because the printer uses a Core-XY design, only two motors are used to control the X and Y axes simultaneously.

X & Y Axes

The X and Y axes motors are driven using higher-quality DM542T drivers from StepperOnline. These are capable of being run at 200 pulses/revolution, giving better response time than most stepper drivers.

Z Axis

The Z axis, which uses 4 stepper motors, could theoretically be controlled with a single driver by wiring all the steppers in parallel. However, this would not allow individual control of the steppers, which is required for convenient features like Klipper's bed tilt compensation. This feature is specifically for printers that have beds with 4 separate steppers, and allows the printer to correct for a non-flat bed by slightly adjusting the height of each corner. It's not yet known how useful this feature will be, but it could be a significant time saver when it comes to leveling such a large print surface.

Because the Z axis does not need as precise/fast motion control as the other axes, we used cheaper TB6600 stepper drivers instead.

Extruder

The extruder motor is small enough that we can use the TMC2209 stepper drivers included with the Octopus board.

Voltage Levels

Both the DM542T and TB6600 drivers require 5 volt logic to operate. However, the Octopus board stepper outputs only use 3.3 volt logic. Because of this, logic-level converters such as these are needed.