Indicating the top of the #1 gear shaft to verify truth relative to table travel. The length of the shaft is better than 90 inches, so the right hand end is supported on a roller, out of sight, to reduce the strains on the milling machine. With this setup, the depth of cut is determined by lowering the cutter from above as the roller setup cannot be disturbed and get good results. The cutter in view is a 3/4 inch hogging (roughing) end mill. The finished keyway is to be 7/8 inch wide.

Photo by Rick Brigger