A few years ago, I got the bow saw (a.k.a a turning saw) kit from Tools for Working Wood and set out to make myself a useful tool. Initially, I was very happy with the result, and I found myself using it frequently.
Soon, however, a couple of flaws appeared. First, I hadn’t drilled the holes for the pins precisely straight, so the blade kinked at one end when I tightened it down. Second, the arms were shaved down too thin at the bottom. They flexed too much, preventing me from putting enough tension on the blade to keep it straight. The result was a saw that worked, but that wandered in the cut and tended to break blades frequently.
This week, I finally got around to making myself some replacement parts.
I salvaged the handles and the toggle, but the rest of it is new. Like the old saw, this one is made from pecan, a heavy wood that is quite springy and difficult to split. I found a couple pieces with spalting in them, too. The third piece is less colorful, but the grain is straight, and I had it on hand.
The new saw is much more rigid when tensioned, and it cuts more cleanly.
Here is the new one with the old pieces. Notice that the old arms taper down to nearly 1/2″ just above the handles, whereas the new arms taper down to about 3/4″ . That allows much less flex in the arms when the saw is tensioned. I also made a new, double-ended toggle so as to be able to set the tension more precisely by half-turns rather than by whole-turns.
One design element I did retain from the original is the detail at the top of each arm. Most turning saws have a simple hook shaped in the top to capture the string. This “loop” detail has no particular function besides making it more difficult to string the saw, but I like the look, and it makes the saw unique.
I hope this saw remains functional for a long time now.
[Edit to add: I wasn’t long after I rebuilt the frame that I noticed that the middle stretcher had bowed out to one side, which not only distorted the frame (again!!!) but effectively shortened the saw. I realized that while pecan is split-resistant and flexible, making it ideal for the arms, that very flexibility makes it unsuited for the center stretcher. So I replaced the stretcher with a piece of black walnut, which is both lighter and stiffer than the pecan stretcher. I’m reasonably happy with the saw now, though the only available blades for it are very thin and break too easily. Soon I’ll make myself some blades out of a 1/4″ skip-tooth bandsaw blade.]