M12 extruder bolt or axle hobbing tool

thingiverse

Tool that will help make 12mm hobbed bolt or axle for a filament. BOM Printable: hobbing tool 1pc Hardware: DIN 618 hk1210 bearings 2pcs Print Settings Printer Brand: RepRap Printer: prusa i3 Rafts: No Supports: No Resolution: 0.2 Infill: 25 Notes: 230C hotend 100C heatbed 15 lines brim Post-Printing Clean. Press-fit bearings. Clamp in a vice. Insert bolt or axle with dredging, fix with nuts. Insert M3 tap into electric drill or screw with adjustable rpms. Apply drilling oil on dredging and tap. Actually, any liquid oil will do, but machine or special drilling are best choice. Don't do this without oil. You'll definitely screw things up. Hold drill perpendicular to an axle. Push drill harder to the left, as it'll try to escape to the right. Start drilling on as low rpms as possible. Hold the drill tightly on the same place so that axle to rotate steadily. Otherwise, some notches will be deeper than others. Continue, sometimes cleaning the dredging and tap and applying more oil. Repeat till axle will make few complete revolutions. Verify results visually. If somewhere notches are not deep enough, tap that single area by slowly pushing drill forward while drilling. After crafting two axles, bearings most likely should be thrown away, or kept for hobbing only. They should not be used somewhere due to metal chip that will definitely get inside.