What is that? It is one of the knows from the Frigidaire stove top. They are made of plastic and are not very durable. When a child turns it beyond the range of the valve it controls the half round hole breaks. Unfortunately, Frigidaire does not offer a metal form of this know probably to make sure some overly exuberant child does not break the valve. Still, it is frustrating to pay for these not very durable plastic knows.
I am going to start with a piece of 2.25" aluminum rod and turn it on the lsthe to the dimensions of the top and stem parts, then machine the half round hole that goes over the valve. This has involved measuring dimensions, and calculating the chord that makes up the half round side. And no, it is a perfect semicircle. The flat side is a bit more than 98 degrees of arc. This will involve cutting a straight line for the flat side of the hole, than a counterclockwise motion to the other end of the chord, repeated down for 2.107 inches. I had to order a 3" overall length .125" carbide endmill. This will be a very slow .01" depth cut. Yes, that involve a lot of patience.
My plan is to make one, verify functionality, then replace the other four. Once I have the code for milling the half round hole, the rest will be pretty quick.
