The Riuda 6442 laser controller has a fourth axis but the firmware does not support using this axis to drive a rotary. This video describes how to have a dedicated rotary axis on a laser with the 6442 controller. A front panel mounted toggle switch selects whether the motion is intended to be the Y axis or the rotary axis. The parts were purchased from Amazon at a total cost of about $40. The parts needed are a DM542 stepper driver, a three pole double throw toggle switch, and a male/female connector to connect and disconnect the rotary motor. Remove the connections from the 6442 Y axis and replicate this wiring to the center connections of the 3 pole toggle switch. Wire one side of the toggle switch back to the Y axis drive. You have basically placed a switch in the wiring between the controller and the Y axis stepper drive. Connect the other side of the switch to the Rotary axis stepper driver.
Stepper Driver:
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Switch:
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Connectors:
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