Professionally made zero clearance table saw inserts are an important add-on for any table saw. They make the cuts come out cleaner and ensure small scraps don’t get lodged inside the throat. They are quite expensive though. They run over 30 bucks a piece for my saw. No more, time to make my own. I bought a smallish piece of phenolic coated plywood for 40 dollars. It has enough material to make at least 8 inserts.
I started off trying to make a jig that would hold the plywood and make all the blade relief undercuts and slots for the riving knife behind the blade. It was difficult to hold everything and produced mixed results.
Eventually I just used carpet tape to tape down one of my old store bought inserts. A guide bushing on my plunge router let me remove all the area where the riving knife should be.
From there I printed a 7/16″ radius template for the tracing router bit. I could have used the already taped on insert as a template, but it had a few weird features I didn’t want copied. With a finger hole drilled in, things were starting to look right.
I need a way to level out the insert. The pocket they go in is always deeper than a 1/2″ sheet of plywood so you can raise it up to be flush with the top. I used brass threaded inserts for #6 set screws to give each one leveling feet. The set screws can be adjust from above with the insert in place.
The surface coating on this plywood is hard and very slick. A great material for fences or inserts like this. The phenolic chips like mad though. I will stick with these and have left over material, but probably not buy it again. A few coats of polyurethane and wax would be easier to work with and also reasonably slick.
Because of how high the 10″ saw blade is in the housing I had to use a 8″ dado blade to start the cut before switching back to the full sized blade. I made 4 total, and once I got the swing of things they came pretty quickly. Two will be for dado cuts, so they don’t need the riving knife slot. Hopefully this batch lasts me a few years.