17-03-2020, 10:54 AM
Howard, that illustrates my thinking. You can cut a slot in a shaft for a square section key with a rotary cutter or an end mill, but you would only cut a slot for a Woodruff key with a rotary cutter of the correct diameter (I'm sure you could cut it to the correct radius by other means, but not efficiently). Given that the benefit of a Woodruff key is that it will self align parallel to the hub axis (I.e. the leading edge stands up more from the taper surface than the the inboard edge) and cannot work its way out along the keyway, which is blind at both ends, why would anybody design such a skinny key requiring a potentially unstable tool to cut the slot in the shaft? A rotary cutter 3/16" thick with a diameter of 2 3/4" would be very tall and thin for stability when cutting. It would be interesting to see a photo of the keyway in the shaft from Tod' s car.