I need some pointers on cutting double keyways in a shaft. Its a 2 7/16 with 5/8 keys 180 degrees apart. I've been doing it by scribing lines across the end with a center finder and lining it up with a level. Theres gotta be a better way. It has always worked out OK, but I just don't feel like its the most accurate way to do it. I'm cutting it with a knee mill and a 5/8 end mill. The lumber mill is waiting on me right now, so a quick reply would be much appreciated.