Yeah, it is all in the technique once the saw is properly tuned. I've also tried pulling ever so slightly to the right and to the left on alternating strokes or every x number of strokes for example 5 pulls to the right followed by 5 to the left and that works fine. And not being overly focused on the line, that is to say not exclusively on the line but just as much on overall balance, feet centered on the beam shoulders perpendicular to that and relaxed, and a light grip. I also watch the blade to see that it is straight and vertical when it's tensioned.
Whether or not it is realistic to expect to cut a straight and vertical line in one shot I cannot say. An old teacher of mine in cabinetmaking school told me he always cuts from both sides.

Regards,

Don

How long does it take to rip a timber with this saw?

Also on the topic of such saws, would there be any such a saw that would have been in use in the high to late Middle Ages? I would be interested in such a method as a possibility in stead of splitting, although I have so far had fairly good results with splitting the logs in half.

I experimented with splitting timbers in order to yield 2 or more timbers out of a larger log. My experimental tree was a large pignut hickory 18" in diameter at about 18 feet, maybe 20" or so at breast height (so in timber terms, the tree was 20" DBH)

In all I'd say my results were acceptable to good. With practice I may be able to bring the split more in line with where I want it to go. This is accomplished by forcing the split to go a certain direction, which can be controlled to some degree by splitting both sides of the log at once, pushing up one side more to 'spiral' the split if the split wants to go down or up on one side, with careful attention paid to where wedges on opposite sides of the log are in relation to each other. Kind of the same Idea as flexing a riven section of wood when using a froe to keep the split in the middle. You can also force a stubborn split to go up just by cutting a new split line above or below a wondering line, but this will create a holding strap that you will have to cut through later with an axe or saw. With this you can find that it is possible to make a straight split in an imperfect log. Although it's still best to be sure the log has at least 2 or 3 extra inches of width.

Let's put it this way, I started at the beginning of the football, sorry soccer game, it went into one extra time session so that is 90 min plus I think 15 min so 1 hr 45 minutes for the whole game and that is when I finished the cut. Plus I stopped to file the teeth.

I can say there were no Japanese saws in the middle ages 'cause the Dutch did not make contact with the Japanese 'till around the beginning of the 16th century. There were only two man saws generally in use in the middle ages for comparable work although the Dutch were by then using wind driven saw-mills while the rest of the white men here were still hackin' away with their axes - like we so love to do..

Greetings,

Don