An update on the flat toothed saw test:
The Story of Two Saws
Given two nearly identical saws, one with normal pointed cutters and one
with flat top cutters, what one will cut better and what one will need less
The idea of the flat tooth was that most of the wear would be on the leading
and trailing edge of the cutter and the knife edge would not need sharpened
for a long time. With just the leading and trailing edge of the cutters
needing only touched up, the height of the cutters would remain the same.
There would be no need to mess with the rakers or joint the saw on a regular
So how did it work? I cut maybe 4 cords of wood with the two saws,
changing back and forth on most every cut. At first the flat toothed saw out
preformed the normal pointed toothed saw. It cut about 10% faster with
much less resistance. It ran very smooth, almost the point of wondering if
the saw was actually cutting.
About half way through the experiment the two saws equaled out in cutting
speed with the flat toothed saw still running smooth. Over time and toward
the end of the test the flat toothed saw required more and more down
pressure to get it to cut well. The pointed tooth saw was still cutting well.
When I stopped the experiment the flat tooth saw was not cutting nearly as
fast as the as the pointed tooth saw and was requiring too much down
pressure to be serviceable.
Upon a close inspection of the flat toothed saw it is evident that the knife
edged points of the teeth were showing wear. So the original assumption
that there would only be wear on the leading and trailing edges was wrong.
And if you think about how a saw really moves through the wood that makes
some sense. When sawing the saw moves both inline with the axis of the
saw and down into the wood perpendicular to the axis at the same time. The
vertical part of the movement caused the knife edge to wear and the dulling
of the knife edge. This dulling required much more down pressure to
advance on the cut.
After this experiment I would not recommend filing cutters with a flat top.
This show the wear on the knife edge