Made this today while putsinnaroundmin the garage. The cutter I made out of an old diamond hot saw blade. Drilled a hole, and chucked it on the drill, and shaped/sharpened it on the bench, and belt grinder. The bearings were scavenged feom a pair of discarded inline skates. Cut the groove with a skinny wheel in my 4-1/2 angle grinder. The screw is from a cheap c clamp. It worked pretty well on this filter I picked up a few years aback at a yard saale for a dime.
