Minggu, 07 Februari 2016
The traditional choice for this joint needs three tools: saw, chisel and router plane.
Another option is to use dedicate planes, but while for the male element the choice is wide, for the female part of the joint the specialized planes are rare. Japanese tools, instead, have a Ari-Kake-Shakuri-Kanna for this purpose, a grooving plane needing a separate angled fence for its job.
As this joint is mostly cut across the grain, it is necessary scoring the wooden fibers before.
The plane for cutting the female element is a sort of dado plane, indeed, only with angled sole and skewed blade.
Finally I decided to make a self made one and here is the result:
FDT means "Female Dovetail" and 6 is the blade width (6 mm)
The blade is skewed at 20° and the sole is inclined at 78°, the same of male cutting plane. The blade is bedded at 50°.
It has an adjustable depth stop and a double spur for cross grain cuts.
The woods are beech for the body, mahogany for sole and wedges.
The body building is quite simple. I cut a rabbet for the 6 mm bottom part.
I cut rooms for blades and wedges and glued a piece of mahogany to the bottom.
I planed the sole at 78°, controlling the correspondence with the male element.
The critical part of the job is to find the exact correspondences between angled sole and skewed blade and wedge.
For the blade I used an old plane iron, for the nickers a 10 mm spade bit, grinded ad hoc.