A precision gantry stage or gantry system is sometimes called a linear robot or Cartesian robot. Gantry robots typically provide overhead motion in 2 or 3 linear degrees of freedom (X-Y and X-Y-Z) and are often used for pick and place applications, 3D printing or laser machining, precision handling, and electronics applications. These precision automation systems only share the name and general layout with the high load gantry cranes often used in ports for loading and unloading of cargo.
The advantage of an overhead XY gantry or XYZ gantry system, in contrast to a split bridge granite motion system or traditional XYZ linear slides or XY slide assemblies, is its ability to keep the work piece stationary and move sensors, laser heads or dispensers above the work piece. Gantry linear robots also cover a relatively large work area on a relatively small footprint. Gantry granite motion systems often include a manipulator / gripper mounted on a vertical axis.