Here’s the completed project.
The instructions call for the holding screw to be machined from a piece of brass or plastic so as to not mar the micrometer. What I ended up doing as making it a steel knurled nut instead. I threaded the center, then ran a nylon screw through the center.
My original plan was to melt the nylon screw into the nut so they would become one piece. I envisioned cutting a couple of groves on the top to make this happen. In the end that wasn’t necessary, as it works just find by hand-tightening the plastic screw then using the nut to lock it into place.
Knurling on the Mini Lathe
The mini-lathe has trouble dealing with the forces involved in knurling steel. I had to replace the lever on my quick change tool post with a nut that I could crank down hard using a long wrench.
The last time I knurled something was over a decade ago so I’m sure that I’m forgetting a step or seven, but it worked out well enough to be usable.
Tilt Adjusting Screw
I made this out of a single piece of 1/2” cold rolled steel. The plans call for 3/4”, but I already have 1/2” chucked up from the previous part. And really, 3/4” seems overly large.
In theory I could have used a piece of threaded rod that was glued into place, but that’s kinda cheesy. So I did turn it down to the correct screw diameter. Actually I went a thou or two under on the theory that if my cheap digital calipers were off it was better to err on the low side. (No, I don’t actually own a micrometer. The stand is a gift.)
Cutting the Threads
The first attempt was a dismal failure and I bent the part. Not willing to start over, I straightened the shaft using repeated blows from a lead-filled, rawhide mallet.
That taken care of, I tapered the end so I would actually stand a fighting chance. I normally don’t like doing it because changing the angle on the compound slide it a pain in the ass. But after doing so, the threads were easy to cut.
I used a die holder from Little Machine Shop so I didn’t need to remove the part from the lath. This has always proven to be much more reliable for me than using a hand-held die holder.
I’m not entirely sure why I needed to make this screw (besides the learning experience). It seems to me that a normal set screw would have done the job equally well. Is there really any advantage from only threading half of the screw?
Trying to part this off using the lathe’s parting tool was silly. It snapped long before I got close to finishing the cut.
Thankfully I had a small vise. So I racked it up and finished the parting operation using a Dremel’s cutoff wheel. Then I cut the slot for the screw driver using the same tool.
I used Birchwood Casey Gun Super Blue to add a protective finish. It’s always worked well for me so I haven’t tried anything else.