1 Attachment(s)
Incra box joint jig - brilliant
I would describe myself as a "box joint aholic". I've made dozens of boxes using them. I really like the final look and so does my family. Over the years I've made 4 jigs including my most recent, the one in the photo, based on this video ( https://www.youtube.com/watch?v=aiqpKV0OnGY&t=1s ) which has adjustability by feeler gauges and yet all of them while doing a good job didn't give me the repeatability I was after.
I bit the bullet last week and bought Incra's box joint jig combined with Freud's box joint blades. I followed the instructions exactly which requires firstly that the pins need to be snug against each other and later the final pin width should allow a snug fit when the previous cut slot is placed on it, but was does snug really mean? I always ended up with the joint too tight. I then saw this video ( https://www.youtube.com/watch?v=-GszYAh0Yhg&t=13s ) which mentions the fingers should be 0.006" smaller than the slots so rather than following Incra's instructions I made a test cut using callipers, measured the slot and fingers and using the micro adjust on the jig, which allows for 0.001" adjustability, was able to dial in that 0.006" difference every time. Did another test cut to verify and the results are perfect every time. That 0.006" difference is a perfect amount for glue. Less than 0.004" difference made the joint too tight.
So I can now make any box joint any size (using Freud blades or dado stack) with dead on repeatability. As big Kev used to say years ago, "I'm excited"
Attachment 521376