Table Saw Tenon Jig
A recent discussion on WoodCentral led me to dig through some old photos to find an example of a great jig for cutting tenon cheeks on the table saw. If you’ve ever fiddled forever with a jig that rides in the miter slot or cringed at the sight of someone manually running a thin piece of wood vertically over the saw blade, this is the jig for you. It is safe and precise and I wish I had thought of it. I first saw it in one of the best woodworking books ever written, “Cabinetmaking & Millwork” by John Feirer.
It doesn’t take long to make, and the only key dimension is the top piece of the upside-down “U”. That needs to be the same as the width of the table saw fence, maybe a hair wider so that the jig slides easily. If the fit is a bit tight wax the inside of the jig. Hold the three pieces together with screws so you can take it apart and trim that piece if you need to. The goal is to have it slide easily without any sloppiness.
Make fine adjustments by moving the fence. Use a zero-clearance insert and if you keep the insert fresh you can line up the layout lines to the kerf in the insert. Make your cuts so that the waste falls away from the blade.
The piece that holds the work is about 8″ wide and 10-12″ tall. The vertical back up piece is also held on with screws. Keep the screws above the blade. If you don’t have a hold-down clamp you can use an F-style clamp to hold the work. If you use this very often the hold-down clamp speeds up the process.
The shoulder cuts were made previously and are used to set the height of the blade. Set the height before you set the width by clamping a piece in the jig and sliding it up to the inside of the blade. Raise the blade until a tooth at top dead center meets the cut line.
The last piece of the jig is the short piece across the top. Use that to push the jig across the blade. After the cut slide the jig back until it is well away from the blade, unclamp the cut piece and turn it end for end to make the next cut. If the tenons are centered you can flip the work over to cut the other cheeks. I usually have a slight offset to make getting a perfect thickness easier and to keep the faces of the work oriented correctly.
I am really curious about this. I have a nice jig it takes a while and is a pain to set up. I finally quit using it and started using sled to cut the four shoulders, nibble away most of the remaining, then a chisel and router plane to clean up. I am sure there are several other methods. I would appreciate your thoughts on the subject.
If you’re nibbling away from both sides, any variation in thickness of the piece will show up in the dimensions of the tenon. The idea of the jig shown here is that you can set up the cut for each cheek to make the tenon the correct size, or at least so close any trimming is minimal.