First, you need to have your star square to the machine. What I do is place a 123 block on my plate. I have a Rayco plate so it is easy to get that square. When I put the star in I eyeball it square to the block. Your dual calsphere needs to be pretty square to the machine also. Next, I calibrate each tip individually, starting with #1. It might take a few tries, but it'll work. Here are a couple of pics of how I do it.