Made a couple small screwdrivers today. I’ve been running into a lot of situations on old machines recently where the length and width of the screw slots are not sized for contemporary screwdrivers. Or at least I have not found them yet, even my recently purchased Grace drivers don’t fit as well as I’d like. So, figured I’d try making my own.
For the shafts themselves I used a couple of hex driver bits and came up with a simple jig to hold them in a repeatable register for grinding the blades. Really, the jig is nothing more than a holder with a through-hole and four set screws to hold the bit in the same place all the time but it took the most time to make.
The grinding was pretty simple, with the rest set at what looked like a good enough angle I just freehanded the bit back and forth against the wheel. Every now and then I’d turn the bit to do the other side to keep the blade more or less centred but that’s it. I had thought I would need a small fence on the rest but as it turned out it wasn’t really needed.
For the grips I used black acetal rod. The bits are an even quarter inch across the flats of the hex and I wanted a good press fit, so I winged it and drilled a 17/64” hole — perfect! It takes some effort to press the acetal on but not excessive, and when I did the two real versions (as opposed to my test version) I warmed the plastic a couple hundred degrees or so using a heat gun. Maybe it made them slide on better, maybe not, but that’s what I did.
After the blanks were pressed onto the shafts it was fairly simple lathe turning after that. Kids, don’t try this at home! Yes I have a three jaw, several actually, but there’s times I want to get in tighter than the jaws might allow so a cordless drill chuck is a handy thing to have around. Not for heavy turning of course, but this is plastic with light cuts so works great. I fluted the grips on the horizontal miller with the indexing setup.
Back to the lathe for some final cleanup of the butt ends and they’re done. Both of these are for specific situations that I run into all the time — the stubby one sneaks in under the head to remove the two needle plate screws, and the pointy one adjusts the tiny tension screw on the side of the bobbin spring.
Thanks for looking!
-frank
