Gantry printer

A gantry printer is a construction 3D printer in which the print head is carried on a rigid frame of linear axes that spans the build area, so the nozzle can be driven in three orthogonal directions over everything below it. The frame is the reference for accuracy, which makes gantry machines the most predictable of the common construction printer types and the easiest to scale to the footprint of a building. The build envelope is fixed by the frame, so the machine has to be larger than the object it prints.

In practice

Crane-type printers are a compact variant of the same idea: instead of a full portal, the nozzle hangs from an arm that rotates around a vertical column, sweeping a circular working area. The advantage is transport and assembly, since a crane machine can be moved and erected by a small team and can be extended by printing in overlapping circles. WASP publishes a nozzle range of 25 to 38 mm for its Crane WASP machine. On any gantry or crane system the practical limits are the same: levelling and rigidity of the structure, keeping the delivery hose clear of printed work, and the fact that the frame or column occupies part of the site for the whole print.

Related terms

• Cable-driven printer — a printer whose head is positioned by winch-driven cables instead of a frame.
• Robotic arm printing — printing with a multi-axis arm, offering freer orientation but less reach.
• In-situ printing — printing an element in its final position on site rather than in a plant.