Summary I started learning a new design software by today and these files were the result. I can highly recommend Designspark Mechanical () and CraftWare () which were used to design and print! It is supposed to be placed in an groove mount compatible extruder and to carry a nut which holds an 4mm bowden tube in place. On the gallery image you can see this thing fits nice in a gregs/wade extruder from Jonas Kühling: Design with Designspark Mechanical Sliced with CraftWare .2mm Layer, .42mm lane width, smartABS by Obritech. Printed very well without any support.