| ▲ Mechanical |
Yet more knurled thumbscrews using a rope knurl! These have a very low-profile knob (only about 2.5mm thick) and use a piece of M3 threaded rod as the screw. The threaded rod is silver-soldered into a shallow cavity in the brass knob. To ensure that everything lined up, I didn't part the knob off fully so it remained attached to the bar stock with a small piece of material - this limits heat conduction away from the knob when soldering. The threaded rod was held in the lathe chuck and the knob+stock held in the tailstock - this allowed both parts to be soldered whilst maintaining alignment. After soldering and cleaning, the knob was cut off and faced.
 Turning the profile for knurling |
 Knurling |
 Cutting recess for threaded rod |
 Deep groove cut to limit heat conduction |
 Theaded rod held in place and fluxed |
 |
 |
 After soldering - sandblast to clean |
 |
 Threaded holder to turn the other side of the screw |
 |
 Finished |
 |
 |
| ▲ Mechanical |