In digital sculpture enlargement machines, “5-axis” refers to the number of directions in which a cutting tool can move. A drill bit in a simple drill press can only move up and down, making it a 1-axis machine. Most milling machines are 3-axis, meaning the cutting tool can move up and down, forward and backward, and right and left. Computer control enables all three axes to move simultaneously which allows accurate milling of complex shapes and surfaces. However, a 3-axis machine can only cut from one perspective or point of view, typically straight down. Undercuts in the surface can’t be reached unless the part is repositioned so that the undercuts are facing the direction of the cutter. This can be very time consuming on complex shapes and may introduce inaccuracies.
5-axis means that the cutting tool can not only move in the same three directions of a 3-axis machine, but the cutting tool can also rotate to approach the work from any direction, enabling easy access to the undercuts that a 3-axis machine can’t reach. It’s a far faster and more accurate approach than 3-axis milling.