Box Joint Jig Project



I purchased an Infinity 080-250 24 tooth saw blade. This is a thick (1/4 inch kerf) flat top tooth 8 inch table saw blade. The reason for the purchase was to be able to cut flat checks and shoulders for tenons. The flat tooth eliminates the "bat ears" that accompany the use of standard tooth blades when used for tenons or dadoes. Image below shows bat ears in a dado.

BJJ-000 Manual PDF

Video on Youtube


Although the purchase was primarily to improve tenons, the ability to use this blade for box joints is clear.

So, I purchased Infinity's box joint jig along with the blade.

In order to use this blade and jig, the first task was to create a zero clearance plate for the 080-250.

Here a blank plate is prepared.


Then the plate is locked down at both ends...don't want it to go flying.
The thick 1/4 inch kerf blade is raised until breakthrough.
The final height was to accomodate ~1 1/2 inches of cutting...a height suited for small table apron tenon cheeks.
The box joint jig will be attached to my Incra 1000 miter gauge.
The aluminum Ultra Track plate was attached to the Incra. These hex keys screws are secured with special washers in the groves...movement of the plate allows adjustment of the location of the jig in terms of being in line with the blade.
The Ultra Track has a cutout that allows the box jig to make cuts to the depth of 1 5/8 inches.
On the front of the jig there is a cutout for the fixed stop and the adjustable stop...these can be adjusted to allow cuts from 1/8 inch to 13/16 inch.
The kit came with a set of adjustment blocks to facilitate the setting of these stops.
For the most part, I will always cut 1/4 inch since that is the blade kerf.
After a quick setup the unit was ready to run for the first it is with the virgin jig face.
After the first kerf cut...

After running the first joint cut in the target board, the unit is moved and placed over the stops and the next joint is cut.

This continues until the board is finished.

After the board is finished, it is flipped and then placed back on the stops...this sets up the correct spacing for the second board.
First test cut...
First dry fit...small gaps indicate the need to tweak the setup a bit...probably an issue in the setup for the stops.

The way to remove the space between the fingers is to move the fence setup in the correct direction.

The target gap is .005 inches. This allows for friction fit with room for glue.

My gap was about .020 then halve the difference, .015/2 = .008...this feeler gauge is placed between a stop block and the attaching plate of the Incra mitre gauge.

The feeler gauge is removed, the locking bolts are loosened and the fence is movef over to touch the attaching plate.

Then the fence is locked down.


Dry fit of first box made with the setup...
See the creation of box here.





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