Here is a lot of how I spent my summer. The article describes modifications to my RF-30 mill/drill to permit the Y leadscrew to be aligned to its ways to within 0.0005 inches in a 4 inch run. Two measurement instruments are also presented. They can detect when the roll and yaw of the Y leadscrew is zero.
If you are interested, please see
A companion article detailing alignment of the X axis is in the works.
Your comments are welcome. All of us are smarter than any one of us.