Thanks bar and madgrizzle for the info, and the excellent calibration guide. I read the guide over before performing the calibration. I believe I did all of the steps properly, but will rerun calibration sometime soon to see. I also want to cut a file with some known measurements to see accuracy.
My frame doesn’t follow the stock designs, but it is similar. I am using the 12’ top bar sold by metal maslow, and the slack is run against the top beam with counterweights. Here are some pictures.