Parts for Adding Third Z Screw to D-Bot

NOTE: Please see the update and the end for description of the latest configuration.

I wanted to add a third lead screw to my D-bot. I also wanted to drive all the z-screws with one stepper, with GT2 belts to keep everything in sync. I added another 2040 extrusion to the front of the D-bot bed and made adapters to hold a 608zz bearing in the motor mount. I also made a motor mount that holds a 608zz bearing at the right position to line up with the lead screw bracket on the bed. These parts ca