Generic head that should fit on Lego minifigures. The neck is reusable for other head shapes.All dimensions have been tweaked for a specific RepRap/Slic3r configuration. Output may differ for other configurations. Main thing to tweak here is the parameter 'd' which controls the diameter of the hole that receives the neck part. The head consists of a head shape and a neck part. The neck part should be reusable for other head shapes.