Simple bolt hobbing jig that clamps in your vice on a mill or tool post in a lathe. Uses 2 bearing to allow the bolt to feely rotate. Also has a hole through the clamp block so you can see the hobbing depth unimpeded by the tap. If you want a diffenent sized clamping part let me know and I'll upload another size. required parts to finish are: -2 x 608zz bearings -2 x M3x25mm cap head screws -2 x M3 nuts I print so the layers are horizontal through the jib. the M3 cap screws ensure that layers cannot delaminate with the insalled bearings. I use an M5 3 flute gun nose tap when hobbing. Once the tap touches the bolt I cut to a depth of 1mm. This give a nice radius for the bolt to grab the filament and nice sharp teeth.