The Birdsmouth Jig for Kumiko
I've had a couple folks ask me recently about stocking this jig in the shop.
That said, things could change down the road if demand picks up. For now, the good news is you can whip one up yourself super easily. I made mine from some scrap Baltic birch plywood, but honestly, any stable wood or plywood will do.
Do you need fancy materials like Baltic birch? Nope, not at all, but it is nicer.
What's key is getting those guide edges dead-on at 45 degrees and ensuring they line up perfectly (that's where the alignment "pins" come in). I just grabbed a spare basswood Kumiko strip for alignment—it fits snug into slots cut on my table saw, no hassle.
The long stick acts as a stop to butt your stock against, keeping everything square during cuts.
It seriously took me no more than 10 minutes to slap mine together, including rummaging for the right scrap piece.
Here's a quick how-to if you want to make your own:
- Cut the base pieces from your scrap wood. Mine are 8" long and 4.25" wide.
- Cut an end of each piece at 45 degrees.
- Put the faces together and line them up so the bottom end of the 45's are lined up. Then cut the alignment slots with them together. No need to measure a bunch, line up and cut.
- I did the bottom one at an inch from the end and the top one about 1.75" from the tip of the miter.
- Set your rip fence on the table saw for the vertical guide slot. I did mine around 1/2" from the opposite edge of the other two alignment slots.
- Add the Kumiko strip to the main pieces like in the pictures above. Glue is optional. Mine is friction fit.
- On the long strip, I did a quick chamfer on the exposed long edges to make mating the two sides a little smoother.
- Done—test it with a scrap cut to confirm.