In some aspects, autonomous motion devices configured to operably connect to a plasma torch of a plasma cutting system can include: a body to support a power supply of the plasma cutting system and move relative to a workpiece; a torch holder connected to the body and configured to position a plasma arc torch tip of the plasma torch relative to a region of the workpiece to be processed; a drive system to translate the body supporting the power supply and torch autonomously relative to a surface of the workpiece during a plasma processing operation; and a processor in communication with the drive system and configured to communicate with the power supply, the processor being configured to control the translation of the body relative to the workpiece in accordance with the plasma processing operation.