I have been thinking about modifications and expansion of my MiniMill and scanning others on the builds site. I want significantly more travel from my x-axis and realize I would need more support to accomplish it. After noticing Stargeezers Vertimill build, I now know I need dual y-axis. However, I'd rather not use a stepper motor on each. I want to preserve the 4th axis in the event GRBL and the xPRO support an independent 4th axis in the future. What about a belt drive for the second y-axis? Can it be done without any backlash problems? Where do I find a grooved belt with my dimensions? Is there a simple way to splice belt if purchased from OpenBuilds?