Finally got my hands on a “maebiki oga”. I’ve been interested for some time with the idea of ripping boards from trees by hand and this particular saw seems to be the best bet. It measures 32″ from end to end and about 12″ at the widest part. It came with a handle which needs to be replaced and as you can see in the photo, that is also the location of the worst rust. I’d estimate it weighs around 6-7 lbs.
The saw body itself is perfectly flat and the teeth are in good condition. I’ve used saws of course for some time now but never really stopped to consider how they even work in the first place. Mostly I’ve used impulsed hardened blades that I just replace when they become dull.
Fortunately Tools for Working Wood has a very useful PDF on their website, courtesy of Gramercy Tools that gives a detailed rundown of saw anatomy, titled, “Elements of Saw Tooth Design”. This helpful PDF covers Rake, Fleam, Slope, Pitch, Gullet Depth, and Set. For the Maebiki below, you can see that it has a positive rake, and a rather aggressive one at that. As for fleam, it has none, which is typical of a rip saw(and will simplify the sharpening process). It also has no slope to speak of. For pitch, it’s progressive, ranging from 3TPI at the heel to 2TPI at the toe which makes it a bit easier to start the cut and then makes for faster cutting once you are moving. The gullet depth is variable as you can see from the image below, but they are fairly deep and that makes sense, given the size and amount of shavings that this blade would produce.
And lastly the set. From what I can tell given my limited experience, the set is moderate on this saw. It’s not totally flat and also not too extreme. Once I actually get the opportunity to try it out, then I’ll be able to determine whether or not it needs to be increased further. And for that, I’ll need to get my hands on a small anvil, or perhaps a chunk of Iron wood, which would be cool to have. I’ve seen it growing in the woods around here, but it’s a slow grower and not so common.
The next step will be to remove as much rust as I can, fashion a new handle and begin the sharpening process. For that I was able to find a 150mm feather-edge file to sharpen the teeth on eBay for $12, which is the largest I’ve been able to find so far. I’ve never sharpened a saw before, let along one as large as this one but I think having bigger teeth will make it easier in one sense and be helpful in measuring my progress.