This piece of joinery was made for an assignment in my history class, Global Traditions.  I chose to re-create a piece of japanese joinery called the "kawai tsugite joint".  This type of joinery was created by Shinobu Kobayashi while lecturing at Tokyo University.  This form of joinery can be rearranged in 3 different ways; either a straight joint or 2 corner joints.

Kawai Tsugite Joint

Straight Joint

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The image above shows all the different faces of the joint that must be drawn out before the joint can be made.  Every face is the same but rotated in a different orientation. 

You can see in the image above how each face of the joint was marked.  This joint uses a perfectly square piece of lumber.  In my case, a piece of poplar hardwood measuring 2-7/16" x 2-7/16" was used.  

The areas shaded in green represent the parts of the joint that must be cut out.  Once these areas are marked, the temporary lines can be erased.

Step 1 - The first step in marking out the lines is by making a perfect cubic square (red lines). Next draw the 45 degree lines from corner to corner (blue lines).  Lastly, mark the lines from corner to midpoint (green lines).

Step 4 - The next step is cutting as much of the wood out as possible with a saw.  This will help provide a smooth surface for chiseling and also save more time.  

Step 6 - This portion of the joint was the hardest to make since more chiseling had to be done. 

Step 8 - Once I had the straight joint fitted, I tested the square joint.  Once again I had to chisel more out to make the joint flush.  

Step 2 - The next step is cutting off the corner of the post.  The portion to be cut off will be along the 45 degree lines marked from corner to corner (see image from step 1). 

Step 5 - Once everything was cut with a saw I chiseled out the wood between the cut portion of wood.

Step 6 Continued - The image above shows how deep this pocket had to be chiseled out.  

Step 3 - Once the corner is cut, new lines must be marked on the cut face.  This was done by connecting the points on the other faces (see image above).  Once these lines were drawn I shaded in the areas to be cut out.  

Step 5 Continued - The image above shows how much wood I was able to chisel out between the cut portions of wood.  Everything past that point was chiseled out very carefully.  

Step 7 - Once all the pockets were chiseled out on both pieces I put them together.  I first tested the straight joint and found out I had to chisel more out.

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Step 9 - The final step was erasing visible lines and staining the wood.  I decided to stain one joint darker than the other so once they were together they would stand out from one another.

Built 4/15/15 @ 3:11 pm

Updated 4/18/15 @ 6:36 pm

Straight Joint