(This is mostly metalworking, though it does use wooden jigs and scales eventually)
After building a cheap folding knife kit from Woodcraft (which was just making some scales, bolting things together, and sanding/finishing), I became interested in making one myself from scratch. I talked to a coworker who makes knifes and did some internet research before placing an order for lots of knife stuff from Jantz supply:
This includes a flat bar of O1 tool steel for the blade and mechanisms, brass liners and hardware, a jeweler’s saw frame and blades, some buffing compound, epoxy, and a rivet drill bit. I’m going to use the stock removal method to make this knife, which is just a fancy way of saying that I’ll grind the crap out of a chunk of steel until it looks like a knife.
Next was making a design for the blade and mechanics in sketchup:
This will have a lockback mechanism for keeping the blade locked open. Spring tension keeps the hooked locking bar in the blade slot when open, and keeps the knife shut securely when closed. I then laid out the patterns and started cutting the O1 steel bar. As it turns out, tool steel is extremely difficult to cut (who would have thought)... I ended up breaking 3 jeweler’s blades, 2 cutoff discs for the flex shaft grinder, and ruining one scroll saw blade before giving up on that route. At least I got it done eventually:
Next was the rough grinding/shaping/drilling the blade and components. I mainly used my 8” slow-speed grinder and oscillating spindle sander. This also took forever (and burned my fingertips a few times, of course):
I then built a simple jig out of plywood for test-fitting the pieces. Since I’m no expert machinist, I needed to test-fit, remove a little metal, test again, remove more metal, and repeat until the locking/folding mechanisms fit well. This worked pretty well, though the final grind ended up with a slightly sloppy lock (really difficult to get it to fit perfectly):
Since the loose fit was bothering me, I epoxied a shim to the end of the locking bar (we’ll see how it holds up) which is curing right now. I also epoxied one of two shims to the back bolster piece to match the blade washer thickness. Lots more to do tomorrow.
-- Allen, Colorado