Rather than modify M5x80 (or longer) screws, better to use all-thread rods which most hardware stores will have.
Discussion of this here: Shapeoko CNC Router, Rigid, Accurate, Reliable, and Affordable
Rather than modify M5x80 (or longer) screws, better to use all-thread rods which most hardware stores will have.
Discussion of this here: Shapeoko CNC Router, Rigid, Accurate, Reliable, and Affordable