I am working on designing a large format laser cutter, and want a motorized adjustable z bed. Currently I am thinking of running it on 4 (probably more like 8) acme leadscrews. The problem I am coming up with is how to drive all the leadscrews. I think the optimal option would be to attach a timing pulley to each acme screw, and run them all together attached to one stepper motor in a loop. I have two questions: First, is there a timing pulley with a 8mm bore anywhere, or do I need to go with a clamping hub and the laser/print an appropriate gear? Second, how do you join 2 ends of a GT2 belt? If this method doesn't sound feasible, are there any suggestions?