All tablesaws need outfeed support in one form or another. Sometimes that support comes in the form of a helper catching the work as it comes off the saw, but more often than not the support comes from a table of some sort attached to the back edge of the tablesaw. These outfeed tables are critical to the safety and predictably of using a tablesaw.
When an outfeed table is added to a tablesaw there is one aspect that often causes some consternation – those miter slots, and how to extend them into the outfeed table surface to accommodate the guide bar of a miter gauge or crosscut sled extending past the table while completing a cut.
I use a very simple fixture that can easily and accurately accomplish this task. It lends the accuracy of your tablesaw fence to your outfeed table. To make this simple fixture all you need is a straight piece of wood that is rigid enough to function as a fence for a router, and some clamps, your router, and a suitable bit. I usually use a 1/2-in. spiral downcut bit for this sort of thing.
Simply clamp the router fence onto the tablesaw fence and line it up so the router bit lands in the outfeed table just past the edge of the slot in the iron, and lock your tablesaw fence. Run the router to the desired length of extension and add a stop to the router fence to control the length of the slot. Once your length stop is set, you can control the width of the slot by moving the tablesaw fence the appropriate amount to overlap your cuts until you have enough width to accommodate the miter gauge bar.
This setup lets you precisely and predictably control the length and width of your miter slot extensions by using the adjustment inherent in your tablesaw fence to control the router across your outfeed.
So when you are considering your tablesaw setup, be sure to consider adequate outfeed support and think about this simple fixture to take stress out of extending your miter slots.
Bob Miller is a custom furniture maker and woodworker based in the Charlestown neighborhood of Boston. In addition to his own line of work, Bob manages The Charlestown Furniture Makers, an 18-tenant co-op, solar-powered woodshop located in the Sullivan square area of Charlestown.
Bob also teaches for the continuing education department of The North Bennet Street School, primarily teaching Bowl Turning and The Fundamentals of Fine Woodworking.