A1 mini simple clip-on plotter pen holder

A much simpler and more stable pen holder attachment for A1/A1 mini extruder, that turns your 3d printer into a plotter. This is inspired from the amazing work pen holder model by gustav.ferdman. Compared with that, this elimates most of the structural parts and it works as a extruder front cover that can be clipped onto the slots of the extruder. It's designed to hold a 10mm wide ball pen, is more stable than the original springy model, and easier to install. It needs no support to print, no screws to install. Assembly is easy even a 3yo child can do it, just slide the holder part into the base part.