This tenon cutting jig will help you cut the end pieces of wood in a safe and manageable fashion.
In order to do this, you need a tenon cutting jig that adjusts to fit and slide along on the table saw fence. The jig should keep the wood secure and perpendicular to the table, move smoothly, and keep hands well away from the blade.
Step 1: Materials
12 x 12 x ¾ inch Baltic birch plywood
12 x 6 x ¾ inch Baltic birch plywood
2 @ 12 x 4 x ¾ inch Baltic birch plywood
4 x 4 x ¾ inch Baltic birch plywood
1 x 1 ½ x 12 inch strip of hardwood
2 @ 5/16-18 Hanger Bolts
2 @ Four-Arm Knob, Female
A dab of paraffin (candle wax)
Step 2: Measurements
Measure the height and width of your table saw fence. This determines where the 12 x 6 x ¾ inch Baltic birch plywood will be located perpendicular to the 12 x 12 x ¾ inch Baltic birch plywood.
Step 3: Make the Tenon Jig Adjustable
Cut two 3/8 x 2 inch holes on the router table at 2 inches from each end of the 12 x 6 x ¾ piece, starting ½ inch from the edge of the board. This groove should extend across the width of the fence. Glue and screw the 12 x 6 x ¾ perpendicular to the 12 x 12 x ¾ piece 1/8 inch higher that the fence height.
Step 4: Make It Durable and Ridgid
Cut the 4 x 4 x ¾ blocks diagonally to form supports for the 12 x 6 x ¾ perpendicular. Cut the 12 x 4 x ¾ inch plank so that it 1/8 inch greater than the fence height. Drill and screw the 2 @ 5/16-18 Hanger Bolts into this piece so they align with the longer slots cut in the 12 x 6 x ¾ perpendiculars. These need to be parallel to the face of the 12 x 4 x ¾ inch plank so use a drill press.
Step 5: Using the Tenon Jig
Fasten this section to the frame using the female Four-Arm 5/16 knobs. Place the jig over the fence and tighten the back so that the jig slides easily along the fence. Use some paraffin (candle wax) to help this along. Locate the 1 x 1 ½ x 12 inch strip of hardwood along the 12x12 face, perpendicular to the face of the table saw. Predrill, glue and screw in place making sure the screws are well above the maximum height the blade can be raised.