I have a plasma table that uses all four drivers of a Gecko G540 (one for x, two for y, and the z). My question is how do I go about interfacing a fifth driver to control a rotary axis? Do I have to disable the x or the y and use one of these to control the rotary motion? I know machines like Torchmate, Dynatorch and others do this, but from a DIY perspective I am not sure how to proceed. Please advise.