Obviously the stock aluminium insert is designed so that the blade can be tilted up to 45 degrees. However most of the time I do 90 degree cuts. So I've been replenishing my supplies of zero clearance inserts. These are just plywood with a slot cut in and 3 countersunk holes.
To make them you need to cut the plywood to width and length. Next using the aluminium insert as a guide transfer the holes through into the plywood. Then countersink to the size of the screw used.
Remove the riving knife and put in the desired blade - this is the only time I advocate removing the riving knife - always operate your saw with a riving knife or splitter. In my case it is a 80 tooth blade for cutting man made materials. Bolt the insert down to the opening and cover with some masking tape or blue tape. Switch on the dust collector and power up the saw.
Then carefully raise the blade so it starts cutting through the insert. Raise it all the way until you run out of stroke on the raising mechanism. Switch off and retract the blade.
Next you will have to extend the slot to suit the riving knife. Mark the position of the rear of the riving knife on the insert. Then reposition the insert (without screws) about another 100mm forward towards the operator. Then stick the insert down with some more blue tape.
Switch on the dist collector and raise the blade again. This time watch for the rising blade just kissing the pencil mark you made.
The insert is complete and you can then screw it down in position after first reinstalling the riving knife. Give it a coat of paste wax, especially on the slot sides, and you are good to go.
|Room for blade and riving knife|