Custom Tenoning Jig

I’d exhausted my tool budget for a project on an expensive router bit, square, and dado-set, so when it came to making the tenons, I decided to try my hand at a precision custom tenoning jig. I decided to keep it simple and only concern myself with square tenons (no angles). I reviewed some example jigs from a couple books (Tablesaw: Methods of Work, by Jim Richey, and Jigs & Fixtures, by Sandor Nagyszalanczy) for ideas and modified them to come up with a plan for this jig.

I wanted to be able to make 0-2” thick tenons in 0-2” stock. This defined the setback from the saw blade and the required table travel. The height of the fence was somewhat arbitrary, but was influenced by a 6” vertical fence and a max cutting depth of 3”. I made the jig deep enough to be stable, but small enough to allow the runner to engage the slot before the tenon hit the blade. I decided to make it a little wider than I had originally intended so I could use my left hand to keep the base flat against the table. I may add a wooden handle to the left side of the base after getting a feel for using it.

I made most of the jig from 3/4” baltic birch plywood. The runners are mahogany. I made the runners slightly large and sanded them to just barely fit in the slots. The bare wood fit very tight and took some effort to slide the upper table on the base. I then applied an oil finish (marketed for toys and food containers) to protect the wood but not build up a finish which would bind up the slots. Finally, I added a liberal coat of paste wax to both faces of the base and the bottom of the upper table, as well as all the mahogany runners. After buffer that out, the base slides effortlessly on the tablesaw and the upper table slides easily along the base. The final jig has next to zero slop in the runners and fences are nearly perfectly square to the table. This is the most precise jig I’ve ever made, and I’m very happy with the end result.

Update: Basic plans are available here: http://dvhart.com/darren/woodworking/dvhart-tenoning-jig.pdf

-- Darren