instructables

Kumiko Jigs - Japanese Woodworking

by JT Woodworks

Kumiko is a traditional Japanese woodworkingtechnique made of wooden strips to form variousdesigns and patterns. There are no nails or metalfasteners of any kind. There is glue used occasionallybut the majority of the pieces are friction fit into eachother using various angles and grooves. Thisinstructable will cover how to make the jigs needsneeded to cut angles for kumiko pieces.

If you're looking to get into kumiko and don't want tomake these jigs, you can buy the jigs here. You canalso buy a kumiko starter kit here which includesthese three jigs and all the pieces needed to make anasanoha pattern. The only things you need to provideis a chisel or block plane.

Now, let's get right into it!

Tools that I used:

Sawstop table saw - https://amzn.to/2ILhw5L

Jointer - https://amzn.to/2ILhw5L

Chisels - https://amzn.to/2yWx7Qc

Japanese handsaw - https://amzn.to/2Ne5jtm

Drill & driver set - https://amzn.to/2H0qTlG

Spring clamps - https://amzn.to/2Kp2FU8

CA (super) glue - https://amzn.to/2NgcnpG

Digital angel gauge - https://amzn.to/2NgXRht

Materials:

The jigs are best made with a hardwood. I usedmaple for the body of the jig and cherry for the stopblocks. Most hardwoods (like oak, ash, hickory, etc.)should work just fine.

Brass threaded inserts - https://amzn.to/2MECrtq

Brass thumb screws - https://amzn.to/2z6tlDY

Insert installation kit - https://amzn.to/2yZRMCM

https://www.youtube.com/watch?v=zId1w-6QfYw&t=57s

Kumiko Jigs - Japanese Woodworking: Page 1

Step 1: Mill and Square Lumber

This step is not applicable if you're using pre-milledand square lumber.

It is very important to have square material whenmaking a project and even more so when you make

jigs for a project. The jigs are the template so takeyour time to make these accurate.

In this tutorial I'm making three jigs, each at differentangles. I mill enough lumber to make the three jigsout of the same piece of wood. Each jig ends upbeing 9" long so I mill a piece of maple that is 27"long.

I start with rough-sawn maple so I use my jointer toflatten and square two perpendicular faces. Now thatthere's flat reference surfaces, I can flatten the othertwo faces using my planer and table saw. When atthe table saw, I also rip my material to the final 2 1/2"desired width.

Kumiko Jigs - Japanese Woodworking: Page 2

Step 2: Cut the Groove

With square stock, we can now move on to cuttingthe groove. Here I made a mistake and made mygrooves too deep. I made them at 1/2" deep but 1/4"is far more comfortable to work with when using thejigs.

There are many ways to cut this groove and I choseto use the table saw. With the blade height set to thedesired groove depth (1/4") and the table saw fenceset to 7/8", we can start cutting the groove. Here iswhere having the three jigs come from the samepiece wood comes in handy. You only need to cutone groove.

You register the wood on the fence and make yourfirst pass. Then flip the wood around to register theopposite face along the fence with the cut youpreviously made facing the table. Take a second passover the blade then adjust your fence to make morecuts and remove the material between the initial cuts.

*Note: the bottom of your groove may not be smooth.To prevent this from happening, you can use a flat grind blade or a dado stack. If you don't have either ofthese, like myself, you'll need to sand the bottom ofthe groove to flatten it. The best way I found to do thisis to wrap sandpaper around a wooden block that fitssnuggly within the groove. Take your time and go

slow to not mess up the walls or flatness of thegroove.

Kumiko Jigs - Japanese Woodworking: Page 3

Step 3: Cut the Angles

A digital angle gauge comes in handy here. It's veryimportant to cut these angle as accurately aspossible. I made my jigs at 45, 67.5, and 22.5degrees. This angle gauge has a magnetic base.With that base on the table saw table, zero out themeasurement. Then move the gauge to blade, makesure it's not resting on the teeth, and tint the blade tothe desired angle.

With the blade angle set to 67.5 degrees, I'm actually

cutting a 22.5 degree angle because we set zero onthe table. The same setting is used to cut both ofthese angles. Cut one end of your work piece using amiter gauge or crosscut sled. Then cut the other endwith the piece standing upright and along the fence.This can be tricky so be careful and do it at your ownrisk. I made a jig that straddles my fence for thesetypes of cuts. I can clamp my work piece to this jigand cut it safely. It's important to make sure your workpiece is square to the table. With the two ends cut to

their respective angles, you can now set your bladeback to 90 degrees and cut the jigs to length (9").

Kumiko Jigs - Japanese Woodworking: Page 4

Step 4: Brass Inserts

These inserts are added so we can add an adjustablestop block to these jigs to make accurate andrepeatable cuts. Drill the appropriate holes for yourinserts. For the inserts linked in the intro, the drill bitsize is 25/64". I added three inserts into each jig.

There is a tool linked in the intro that helps install theinserts after the holes are drilled. Here is a tip forinstalling the inserts without purchasing theinstallation tool.

Take one of your thumbscrews that fits the thetreaded inserts and file the head into a hexagon. This

doesn't have to be perfect. Just close enough that itcan fit snuggly within a socket head. Now thread thatscrew into the insert and use a socket head in yourdrill the thread the threaded insert into the previouslydrilled hole in the jigs. Make sure the threaded insertis in deep enough and doesn't extend into the groove.Then simply unscrew your hex head screw and use itto install the rest of the inserts.

*Note - Brass is a very soft metal so be sure to drillthe inserts straight into the holes to reduce the risk ofstripping them.

Kumiko Jigs - Japanese Woodworking: Page 5

Step 5: Stop Block

The stop block is part of the jig that will allow you toeasily make repeatable and accurate kumiko pieces.Each stop block is made up of four pieces. Cut stripsto size on the table saw and then cut one of thosestrips down into small blocks. Now glue two blocksbetween two of the longer strips, one on each end,

creating a rectangular frame. I used CA glue for thisbecause is dries quickly.

After the glue dries, trim the ends to make them flatand square.

Kumiko Jigs - Japanese Woodworking: Page 6

Kumiko Jigs - Japanese Woodworking: Page 7

Step 6: Adjustments

At this point I realized I made my grooves too deep(1/2") and trimmed down to height of the stop block.

Make sure the stop block fits within the groove andslides smoothly. Make any adjustments as needed.

The thumbscrews should fit within the channel of thestop block nicely and screw into the threaded inserts.If the flange on the screw isn't large enough to hold

onto the stop block securely, you can add a washerunder the screw to increase its surface area.

These thumbscrews are great and allow quick andtool-less adjustments. The downside is they only holdas tightly as you can screw them in by hand. Toremedy this, I made my stop block long enough to beused with two screws at a time.

Kumiko Jigs - Japanese Woodworking: Page 8

Nice job. Can you put a different angle on each end of a jig?

You definitely can but keep in mind you can only use one end at a time because you would have tomove the sliding stop

What a gorgeous vice!

Nicely done, my friend. Beautiful jigs.

KJ

Thank you Kink!!!

Step 7: Make Some Kumiko!

Congratulations!! You now have kumiko jigs! Thereare many patterns to explore but I recommendstarting with the asa-no-ha pattern. It's the mostcommon and the three angles discussed above arethe ones needed to make it. Kumiko strips arecommonly dimensioned at 1/8" x 1/2" and basswoodis a great and inexpensive wood to learn with. Othersoft woods like pine and douglas fir are great too but Ifind the best results come with using basswood. Feelfree to ask questions down in the comments and I'dlove to see photos of the one make!

You can watch the video here on how I built thesejigs.

You can also find me on Youtube

Instagram to see what I'm currently working on

Facebook and Twitter for behind the scenes shots

Note: This post includes affiliate links. Thank you foryour support!

Kumiko Jigs - Japanese Woodworking: Page 9