Good to know that my saw is acting normally. And thanks for the tip on making an insert. I was wondering about that. Iíll need to find a smaller blade with the right arbor hole or else maybe try to drill out an old blade to make one quick cut. But that makes me a bit nervous
The arbor of a true Unisaw is 5/8", which is the common size of 7-10" saw blades, so you shouldn't need to drill out the hole anyway. Drilling out a saw blade on your own isn't a good idea, because you need it to be very accurate and well centered or there will be a lot of vibration when you try to use it. It's hard on the arbor bearings and not good for an accurate cut. If you must drill out the center hole in a saw blade, it's best to have a machine shop do it. They will have the ability to do it and keep it perfectly centered, but it will likely cost 1/3 - 1/2 the price of a new blade with the desired size center hole.
To make zero clearance inserts, I generally use 12 mm Baltic Birch, Corian from sink cut-outs, or HDPE cutting boards from the dollar stores. I stick the original metal insert to the material using double sided tape, and then rough cut it to size with the band saw. I then cut it to the exact size using a flush cutting bit in my router table. Let the bearing ride against the edge of the metal insert and the bit will cut the material to the exact same size. Use caution when the bearing is crossing over the splitter slot or any other voids in the edge of the metal insert. Leave a little bump by not following the edge closely there and finish using a disk sander to get the edge the same as the insert profile. Then you can saw the needed slot later.
Now mark the new insert with the hole locations for the leveling set screws. You can now separate the metal insert from the one being made and drill and tap for the four leveling set screws. Also drill a hole in the trailing edge of the new insert for a small roll pin, finishing nail, etc. Make it a little small so the pin or nail will fit tightly. Install 4 short set screws to use for leveling with the Allen socket facing up. Now you can test it for fit in your saw and sand the edges if necessary for a perfect fit.
Make a bunch of these while you are at it, so you always have a few ready when you buy a new saw blade, or damage, or just plain wear out a zero clearance insert. I write on the bottom of each insert
to indicate which blade it is for, and I always use the matching insert for each saw blade. There are slight differences between blades, so it's best to always use the insert that goes with the blade that you made it for.
My inserts are almost always made from scrap pieces, and I make about 1/2 dozen at a time, or however many the scrap will let me make. I keep them in the drawer with my blades, so they are close when needed. The spare blanks are kept there too, and I make more whenever I use my last one or have only one left.