If you are looking to buy a box joint jig, I highly recommend the Incra I-Box jig.
It can be used on either a router table or a table saw, and is easily calibrated and then adjusted for different width box joints. Once initially calibrated, changing the size of the joint from one pin width to another is very easy, because the jig changes the pin and space width together with just one adjustment. The calibration is easy too, just turn a silver knob until the finger just lightly touches the blade or bit tooth lightly. Once calibrated, you only need to re-calibrate if the blade or bit are changed for another.
The jig also contains a sacrificial piece that reduces edge tear out and works well when using the jig on a table saw. If using the jig on a router table it's best to add a second sacrificial piece behind the work because the router bit is cutting both into as well as out of the work on both sides due to it's rotation. The included sacrificial piece is just 1/4" MDF. When using the router table I just add a second piece of 1/4" MDF behind my work piece and use both it and the one in the jig to reduce tear out on both sides of the work piece.
When using my I-box jig with a Freud SBOX8 box joint blade set on my table saw, all I need to do is set the jig for the pin width that I want and then make one test cut to be sure that I have the jig set correctly. Them position the sacrificial piece to an unused position and begin cutting my box joints. Like I said before, the I-box jig automatically sets the pin and space width together as you change the jig for a different pin size. The test cut is usually just to get the joint to fit loose enough for the glue.
I make a lot of boxes, many of them with box joints made with the I-Box jig and the Freud SBOX8 blade set on my table saw. After buying this jig, all of my shop made box joint jigs went into the burn pile. The attached photos are of a close-up of one of my recent box joints, made in 12 mm Baltic Birch. They all turn out this good when using the I-Box jig and SBOX8 blade set.
I know the jig's inventor and he demonstrated the jig for me before it was on the market and I knew that I had to have one just as soon as it became available. I have no other connections to Incra or him, except to know him as a friend.
Central North Carolina
Last edited by CharleyL; 06-13-2018 at 08:35 AM.