This is a derivative based on a Wade Nema 17 extruder. It uses a splined model-car insert as pinch wheel... The axis is M4 and the bearings are 624 for axis and 608 for the idler...This thing is working as you can see more or less on my figures. However, for a second version, I would change some things which are not comfortable enough: First, I would make an accessable extruder, with a quick release idler block. Second, the slots for the motor drive are not perfect, that means you cannot slide the motor when it is mounted (hence difficult to assemble). Third, a gear set is needed... I used a hering bone gear set.(On the figure you can see the extruder with a mounted adapter plate... that plate is not part of the extruder. The extruder will fit on a standard mendel x carriage)Instructions:1) Print the parts base.STL and idler.STL 2) Get 2 624 bearings 1 608 bearing 1 M4 axis for pinch wheel 4 M4 spacer 1 M4 model splined model car insert (see figure) 1 M8 axis for idler 1 Nema17 stepper 4 M3 screws 1 * M4 nut 3) assemble the whole thing (see figures...) 4) enjoy :)