A digital readout (DRO) lathe is any lathe equipped with a visual display depicting the measurements along the x- or y-axis. Simple digital readouts display measurements along the axis. More advanced readouts contain programmable memory and can perform complex functions. While companies manufacture digital readout lathes, digital readout kits that attach to existing machines are also available.
A basic y-axis digital readout is a scale running parallel to the cross slide, or machine base. The display is self-contained and traverses the horizontal axis. These simple monitors typically have on/off and zero function buttons, and some displays allow the user to switch between English and metric units. Machines equipped with modules providing basic x- and y-axis readouts also have a scale attached to the carriage, which runs vertically.
Each scale on a digital readout lathe generally has conduit or cords that attach to the back of the monitor. Some liquid crystal diode (LCD) or light emitting diode (LED) displays may indicate x- and z-axes, which are virtually the same as x and y. Lathes manufactured with digital readout usually have the display mounted on the machine. Kits used to convert machines allow users to mount the monitor on the lathe or, perhaps, on a nearby wall.
An advanced two-axis digital readout lathe features on/off, zero, and inches/millimeter select buttons. The readouts usually have a calculator type keypad, and a complex digital readout lathe includes programmable memory positions, diameter and radial measurements, and zero starting points. Options may also include absolute or incremental measurements. The operator can also locate the center of the work piece.
Digital monitors usually display numerals to four or five places. Incremental measurement sensitivity varies depending on the quality of the digital readout lathe. Some monitors and scales detect changes as small as 0.0005 inches (0.01mm). Manufacturers create all types of lathes with digital readout capability, and hobbyists may find conversion kits for machines ranging in size from tabletop mini lathes to large freestanding models.
The display monitor typically provides precise measurements and eliminates errors caused by manual wheel turning. Programmable versions also keep the user from having to remember the number of wheel rotations required for cuts along either axis. Some monitors readily attach to the machine motor, providing speed control.