I'm looking into building a DIY 4th axis for the PRT96. I got a quote from ShopBot for the factory unit and it mentions the stepper has a 6 wire lead. All the steppers I've researched have 4 wires. Is there something proprietary about the ShopBot set up? I'd be buying a Gecko Drive for the "A" slot, so the stepper would have to be "in step" with that drive.