Special planes (tokushu kanna - 特殊鉋)
These are some of the special-purpose planes I use in my shoji and kumiko-zaiku work.
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Ha-ganna
Ha-ganna (葉鉋)
These planes are highly specialized, and used only in kumiko-zaiku, so here I'll go into a reasonable amount of detail on what they are and how they're used. Without these planes the very minute and highly elaborate patterns would be extremely difficult and far too time-consuming, and therefore cost-prohibitive.
They were developed many years ago by the Japanese Tategu Craft Association to speed up the process of cutting the small pieces for the various kumiko patterns.
There are four planes in this group and they are designed to cut at 60°, 45°, 30°, and 15°.
The following two photos show the 45° plane. I use this mainly to cut the pieces for the square asa-no-ha.
For this plane, the blade is folded at about 90° give or take quite a few degrees. This fold angle, though, isn't particularly important.
When I received these planes, they didn't cut at their correct angles. This certainly wasn't a fault with the planes (they are Kinshiro planes, and therefore beautifully crafted); it's up to the user to tune the blades so the cutting angles are correct. This is done purely by trial and error. This is what makes these planes so hard to maintain.
The following photos show how I cut the pieces for the asa-no-ha. For this pattern, I use the 60° and 30° planes. I use the genkotsu method for the asa-no-ha (shown here).
I tape 6 kumiko together (this is a comfortable number) and butt the ends up against the end stop of my jig (the side fence is replaced frequently).
I set the 60° plane against the end of the jig. The fence on the plane has been set so that it cuts the kumiko at exactly the correct length.
One easy swipe across, and the plane has cut a 60° "V" trench across the kumiko. The bottom of the "V" is just below halfway through the kumiko thickness. I then flip the kumiko over and cut the other side, thereby cutting through the kumiko.
I then repeat this with the 30° plane, then back to the 60° plane, and so on. Provided the planes are properly tuned and the fences are properly set, what I end up with are identical pieces with one end 60° and the other end 120°.
And this is how they all fit together.
So without these planes, pieces and joints this small, and even smaller …
would be all but impossible.
Hikouki-kanna
Hikōki kanna (飛行機鉋)
Maru-inrou kanna
Maru-inrō kanna (丸印籠鉋)
