As a designer by trade, of course I would argue that the design phase is the most important phase of any project. In this case there is no exception. I have put a lot of effort in trying to eliminate issues, before starting to actually make anything. Still, after building the printer for the first time I did review several aspects, the belt drive being the main one. I tried to be too ambitious in using plain bearings on the top of the machine for guiding the backside of the timing belts. Instead I ended up using timing pulleys as idlers for the timing belts, supported by two small bearings each. Although adding to the cost of the machine, the resulting driveline is elegant and effective in operation.