A digital position readout (also known as a DRO, short for digital read out) provides a numerical display showing the position of your machine elements. On a milling machine a 3-axis DRO shows the X- and Y- positions of the mill table plus the Z-axis position of the cutting tool.
A milling machine removes material from a work piece by rotating a cutting tool (cutter) and moving it into the work piece. Milling machines, either vertical or hori- zontal, are usually used to machine flat and irregularly shaped surfaces and can be used to drill, bore, and cut gears, threads, and slots.