DrawingBot in OpenSCAD

Beschreibung

Background Some time ago I decided to build a new project, and picked the DrawingBot by MakerC (https://www.thingiverse.com/thing:1517211). A bit of research also picked out the remixes by avanhanegem (https://www.thingiverse.com/thing:2058866) and henryarnold (https://www.thingiverse.com/thing:2349232) - their excellent ideas, designs and other contributions have all been considered in this re-design. After looking at the original designs l decided that I wanted to make some changes - mostly to the idler pulleys and GT2 belt fixing, but also to tidy up a few loose ends that had irked me a little (e.g. limit switch fixing holes). Unfortunately I had no access to the original design files so had to make my own using OpenSCAD. Design basics My design is not as pretty as the originals, as I was too lazy to design the nice curves and neat linear bearing supports (mine are fixed with cable ties). The pieces are mostly straight-edged, albeit with nice curved corners. The minimum requirements to implement the new bearing setup are: XYcarriagebase, XYcarriagetop, Y_back, Y_front, and base_slide. I used the original X-axis motor mounts and Z-carrier, and designed my own M3 knob to hold the pen (https://www.thingiverse.com/thing:2530144). I have included a few extras, e.g. a servo arm that almost certainly will need to be modified to your own needs, as it was designed for my unbranded/unlabelled 9g servo. Note that it's almost impossible to print good servo shaft splines with an 0.4…