Finally ready to start making a riving knife for my old saw. Forrest 10" blade with 1/8" kerf. RK blade will be 0.109" thick and sickle-shaped, with leading edge 3/16" behind saw blade. Clearance from the saw blade to this motor mount casting limits width/depth of the RK blade to 1 1/8". I would feel better with more steel behind my saw blade to prevent pinching, so I'm thinking of grinding a 1/4" wide x 1/4" deep notch in the casting right where the blue tape is. That would enable clearance for a 1 3/8" RK; 22% bigger.
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The highest point where the blue tape is, makes about a 120º angle, with the motor mount, barely visible to the right. Minimum thickness of the casting seems to be about 1/4" or a bit more. The back of the high point of the casting is curved in what feels like maybe a 1 1/4" arc (can't see it). About equidistant from the center (blue tape) and the motor bolts (one is barely visible), on the back side, are a pair of 1/4" thick webs, about 2 1/2" deep at the center, spanning edge to edge of the inside angle of the casting.
My intuitive sense is that such a notch would not materially affect the strength of the casting.
What do you guys think?