These acorn nuts will be used as print heads to extrude the molten plastic on the almost-done Makery Mendel 3D printer. I started the process by holding the piece of allthread (Which has a shallow hole in the end) in the lathe chuck and threading a nut onto the end. I know that generally a bolt thread isn’t true enough to rely on for machining, but in this case, I want the operations all true to the bolt, as that’s how it’s going to be held in use.
Next, I faced off the rounded end of the nut, being careful not to get too deep (which is what happened on the rightmost unit). I then used a tiny drill bit in the tailstock chuck to ever-so-gently drill the hole. On the 0.3mm unit, you can see where the drill bit had a slight bend in it, and wanted to drag around the part instead of start drilling in the center. I was able to change the orientation of the bit in the chuck to correct this.
Finally, I cut a bit of an angle on the side of the nut, making it more conical than round. Sort of like a cut-off funnel. Hopefully it works well. One of the nuts turned out to be plated (which, sadly, is one of the sizes I didn’t make a duplicate for)