Some years ago I made my own Bo Weslien style model of a foldable outdoor saw at Sjövik Folkhögskola. Having no machines at hand back home for high precision wood engineering I was thinking of making a copy of it out of green wood and traditional tools: a froe for splitting a small log to get both handles; axe, shavehorse and drawknife for shaping the handles, carving knife for making the peg, tenon cutter for cutting both tenons at the end of the cross brace that goes into both handles.
Freshly cut maple wood was at hand. The two slots for taking up the sawblade I did with a Japanese saw. The exact position of the holes for the sawblade are given on the packing. Holes need to be only slighthly smaller than the fullthread screws to avoid splitting! Before screwing them in, fix the sawblade with a bolt or a nail opposite where the screw goes in, otherwise it might not meet the exact position in the slot which can result in splitting the handle. While screwing the handle part with the slot needs to be clamped to avoid splitting. Two more holes to take up the Paracord and the sawblade can be tightened. Sawing with it is light work and great fun.
A good project with children or youths. Once you have gone through the tricky bits it might only take about 3 hours to make such a saw out of greenwood.
Making it foldable…
meant a bit of measuring and calculating for a shorter crossbar. I shaved a log of Robinia wood one side to take up the tenons. I also shaved the tips of the crossbar for which I used a log of maple. Then I cut the tenons and did the slots for the blade. To protect the blade when folding the saw I needed to cut a slot all along the back of the handle (last picture). I used a Japanese whaleback saw for that. Handles could have been a tad longer and I should have sticked to the position of the holes as in my first try. Next time.
All in all it is quite compact now but it feels a bit heavy for taking it on tour. I might get rid of some of the material by shaving the crossbar and handles. But in that case it would loose some of its rustic charme.