Original Prusa I3 Mk3 Pen Holder Mod

thingiverse

I've always dreamed of being able to print or draw images on surfaces like boxes, books, glass and such, so I designed this pen holder for my Prusa MK3. It prints without supports, at a 0.2 layer height with 20% infill (basic fast settings for PLA on Slic3r PE). This design clips onto the extruder fan, making it easy to remove and avoiding crashes into the Z axis rods during homing. To secure the pen, simply use two M3 screws and bolts from your spare parts bag if you built your printer from a kit (I'm not sure if there are spare parts available on pre-made models). To allow the tip of the pen to make contact with the surface, I recommend using a rubber band as shown in the picture. I also provide my Slic3r PE settings in the .ini file, which takes advantage of the infill algorithms provided by the slicer depending on the thickness of the pen. Remember to delete any GCODE for bed mesh leveling from your settings, but double-check first to avoid having a pen grinding into your heatbed. Always manually set the Z hop in printer settings, taking into account how far from the bed you want to print and how long the pen is. If you plan to print on a volume like a book or box, make sure to disable auto-home and set XYZ coordinates manually using any software tool (I use Octoprint for this). Don't forget to secure the target surface on the bed so it doesn't move during printing.