Zero Clearance Table Saw Insert

I tried to order a zero clearance insert, but the one listed for my saw didn’t fit well enough so I decided to make my own. I went with black HDPE and bought a sheet. I should be able to do a few inserts with the material I got. With the HDPE I carefully traced the existing insert and cut it out a little proud on the bandsaw. After getting the rough shape I spent a lot of careful time at the belt sander licking away a little at a time, testing, marking, sanding, repeating....

When I got the shape exact I had to make a jig to rout out the edge where it sits on the saw table lip, as well as hog out the material where the plate adjusters fit. I made this out of pine, planed both faces, jointed one edge, made a parallel cut on the table saw for the other, and then brought the width down to just under the width of the lip around the table saw opening. The. I pulled out the existing saw insert again, lined it up exactly, and marked the holes over the adjusting screws in the table. I figured that if I drilled these all the way out with a forstner bit, it would take most of the material out that I needed, and so it did! A little cleaning up around the corners to make the round holes U shaped did the trick for the rest that needed to be removed. When I had the plate on the template to mark out the holes, I also traced the round ends onto the board. I brought the line in from those tracings 1/8” and cut out the round ends on the bandsaw. A little work on the belt sander to finesse this template into the perfect shape and I was ready to move on.

i had a ton going on with two grad school classes, my grad school audition, the insane amount of work my teaching job requires, and a few other things pulling for my attention took up my time while I waited for the bottom bearing router bit I ordered to arrive. I also needed to have my router table functional to progress to the next step, this I completed today (despite still feeling sick from whatever I’ve had all week long....). I measured and marked on the template where the blade would come through the insert. This gave me a perfect spot to drill two countersunk holes to drive screws to secure the HDPE insert to the template. Once secured, it was off to the router table to rout out all but the last 1/8” of edge material on the edge of the template. Once this was done I removed the template and stored it with other templates and jigs for the next insert I make. I took off the puckered up material from around the screw holes with a sharp chisel and moved on. All that was left was to fit the insert, but I had to drill a finger hole so I could remove it again. I did so at the drill press with a forstner bit. I then measured there the blade would come through. And used an 1/8” straight cut bit in my router table to hog out material so that I could put the insert fully in place without it teetering on the top of the blade (the insert is too thick and the blade doesn’t recess that far beneath the table top). Once done I removed the riving knife from my saw, placed the insert in its place (it fits absolutely perfectly with no play at all), clamped and held it down to the table top, and brought the blade up through to make the slot. Since I wanted to have the slot extend far enough for the riving knife I had one more jig to make. I clamped a piece from the edge of my old table saw table onto the fence for zero clearance under my fence, and clamped some board on the far side of my table saw blade just far enough to extend the slot. Then I put the original insert back in, rasied the blade, put the slot of the new insert over the stopped raised blade, set the fence exactly to the side of the insert, held it down with multiple push sticks, turned on the saw, and carefully finished the cut up to my stop block. This done I cleaned up the fuzzy edges left from the router and the saw blade with a cabinet scraper, replaced the riving knife, and tested my new insert. It fits perfectly! One last thing to do is to add a block under the insert to secure the insert from lifting at the back of the blade. I had just enough scrap left over from rounding the ends of the HDPE at the bandsaw to epoxy a bit on to finish the project. It was an absolute success. I’m psyched to have a zero clearance insert again, and I’m more pleased with mine than the one I bought. I’ll be returning the store-bought one.