The hardware for this saw has three functions. It must hold the blade in tension, accommodate blade rotation (when desired), and hold a turned handle. Of these, the first and last are nearly trivial. The second, to allow rotation, yet lock securely when tensioned, is a little more troublesome.
My first design placed an O-ring between the handle and the arm of the frame, hoping that it might provide enough friction to lock the blade in place when it was tensioned. I had some reservations concerning the viability and durability of this design, but went so far as to make the tooling for cutting the O-ring seat.
I had read in the past that some (or maybe most) old frame saws used tapered pins to prevent rotation, but could not think of a good way to make them. When Tony (of Raven’s Edge Toolworks) brought up tapered pins on the WoodNet Hand Tool forum, I started considering them a little more seriously.
The traditional pin is tapered over most of its length. Presumably, the hole it fits into is also reamed out with a matching taper. Now, I have a few tapered reamers, but the idea of using wood as the bearing surface for the pin does not appeal to me. I know that this design has worked well for hundreds of years and millions of people, but still…
Last night, I finally realized that a flanged sleeve with an internal taper (to match that on the pin) might be an even better solution. The flange of the sleeve bears on the outside of the arm, preventing it from being pulled through, while the sleeve eliminates metal on wood wear.
I spent several hours this afternoon at my lathe, and came up with the prototype below. For two reasons, the taper is shorter and steeper than is usually seen. It is easier and faster than turning a long taper, but I also hope that it will be less prone to sticking when the blade is loosened.
The pins are made from two pieces of brass. The blade end is bored out to receive the smaller (handle) end, then the two are soldered together. This is faster and easier than machining the entire part from a solid bar.
The flanged sleeve is made from steel that was heated to 550 degrees in an oven, then wiped down with mineral oil. This heat “bluing” provides some measure of protection against rust.