After I enjoyed making the Box Joint Box for Jeff, I decided to make a more permanent box joint jig for the workshop. I wanted a jig that didn’t depend on clamping it to a miter gage on the tablesaw, that would accommodate different thicknesses of wood and that would be easy to make very fine adjustments with. Borrowing ideas for box joint jigs from several different sources, I designed my own jig in SketchUp.
The most informative video I found was William Ng’s YouTube video, Make an Accurate Box Joint Jig, Simple and Fast. I’ve linked William’s video below. William runs the William Ng School of Fine Woodworking an Anaheim, California and based on his videos, I think he is an excellent instructor with a good sense of humor, too!
I also borrowed some concepts from Phil Huber’s YouTube video, The Ultimate Adjustable Table Saw Box Joint Jig! I’ve also linked this video below. Phil is Executive Editor of the Woodsmith Shop, the video extension of the woodworking magazine, Woodsmith, which I’ve had a subscription to for many years. While William Ng used a quick box joint jig clamped to a crosscut sled, Phil Huber’s jig had it’s own integral runners that fit into the miter slots of his tablesaw.
The photos and captions in the gallery below will give you an idea of the box joint jig I came up with!
My box joint jig design features three adjustable, removable fences to accommodate 1/4″, 3/8″ and 1/2″ material thicknesses
Adjustable Box Joint Jig and Instructions, designed in SketchUp and Layout
A challenging part of this build was fitting the 3/4″ plywood runners and doubled base layer to the miter slots of my tablesaw so the jig moved smoothly and without any side-to-side play
After fine tuning the width of the doubled base and attaching the side rails to it, I still had to use sandpaper and just working it back and forth in the miter slots to achieve smooth movement
Finished sled assembly
The stop block and adjustment screw concept for fine fence adjustment was meant to use feeler gages but I ended up using my mag base dial indicator instead
The two 1/4″ carriage bolts in the adjustable fence go through 3/8″ diameter holes in the sled to allow for side-to-side adjustment of the fence in the thousandths-of-an-inch range
Operator view of the box joint jig
Each one of the adjustable fences will be matched with my dado blade stack set for 1/4″, 3/8″ and 1/2″ box joint finger widths. The corresponding indexing keys will also be matched to the actual finger widths my dado stack cuts
The first test pieces of the 3/8″ finger joint width fit almost perfectly after the initial adjustment was made, based on caliper readings and dial indicator settings
The first box from this box joint jig, made from cherry, will be the accessories box to use with this jig
The accessory box glued and curing in quick clamps
Painter’s tape on the inside of the box joints prior to assembly helps to prevent excessive squeeze out on the insides of the box
Operator view of the finished box joint jig with accessories box and dial indicator set up
A tung oil finish on the legacy cherry of the accessories box highlighted the end grain of the box joint fingers
Beautiful rays in the cherry grain are highlighted by sunshine in the finished accessories box
