Voxel OX single Z axis conversion

If you visit Open Builds "http://openbuilds.org/threads/voxel-ox-3d-printer.4160/page-6" you will see a printer design called the Voxel OX. I have been running it for several years and feel it is an incredible design. I recently decided to modify it so that it only used one Z axis motor instead of two. This allows me to add another extruder. The only new parts you will need are 4 ea. 5 x 16 x 5 bearings and two 5mm shafts, along with the idlers and pulleys and belt. The belt is 1000mm and c