The basic idea is to have the wire feed in thru the top, the rod goes in one end and the exit port is drilled to the exterior diameter of the coil.
The rod is straight with a notch cut into the end to receive the wire. The reason I use a notch instead of a single hole is to make it easy to remove the coil after finishing.
The repair shop should have a lathe or two that you might be able speed up the process.
I usually buy 14 and 12ga electric fence wire at farm supply stores since it is high grade and cheap. The rod I bought at Lowes and I use either 1/2in or 3/8ths in diameter. If you don’t have access to antler to make the jig out of brass might work but I haven’t tried brass yet. Almost everything can be found on Amazon and they have free shipping to all FPO addresses.
Most of what I know about chainmail is self taught. I grew up around a manufacturing plant so making a basic jig came second nature and I have been improving the design ever since.
Oh, good questions! As it stands I have not yet tried this design on steel wire since my power drill isn’t strong enough to wind that type of wire. Recently I picked up a 3.5amp drill and some block aluminum that I plan on fabricating into a jig that can withstand steel.
As for friction that is achieved in two locations; the first is at the spool since it rests on a clamp instead of bearings. The second location is in the jig itself since there is a sudden change in direction the wire naturally resists movement to a point. Because of this heat is generated in the winding process it that helps the wire to maintain its shape, it isn’t as good as real heat tempering but it helps.
Bent rings have never been a problem for me unless I put them under stress. Even with aluminum it can be worn for an extended period without fatigue. My rings aren’t riveted or welded so the risk of popping is higher but unless you plan on taking a spear you should be fine. No chainmail will do well against a piercing blow but my 12ga ½ inch galvanized steel shirt has taken full blows from a hand and a half sword and I only got a dislocated rib and some bruises. When opening your rings you don’t’ want to open them like a “C” instead bend them like a cork screw.
For wire size I mainly use either 12ga on a 1/2in rod or 14ga on a 3/8in rod. The one in this photo is 14ga 3/8in