The Machine
The Facadeprinter is a simple software controlled robot. It consists of a turn table with two axes and an air-pressure print head. The printer shoots the artwork from a distance dot by dot onto the chosen area. Using this method, inaccessible and uneven surfaces can be used for large scale prints. Artworks can be printed on buildings without costly scaffolding.
The Facadeprinter is a large scale communication tool. Print-aesthetic and method are notably different from conventional print and advertising techniques. Artworks are applied directly onto walls, like the drawings of a 'magic pen'. At present, the maximum print distance is 12 meters, the maximum print height is around 8 meters. The shooting frequency is up to 5 dots per second.
Components
The printer is equipped with an industrial PC which runs the specially programmed printing software. The machine is operated by touchscreen. Artworks can be loaded from USB-devices in the file format SVG. Photos of the printing area can be taken using an integrated camera and a printing preview overlaid ontop of them to allow position and scaling to be adjusted as desired on site. The distance from the wall is measured by infrared-meter and entered manually. The printing software then calculates the driving coordinates with respect to both perspective and ballistic distortion.
A modified paintball marker serves as a printhead to shoot the color balls onto the wall. The two axis turn table positions the paintball marker using steppermotors and gears. Before printing, an integrated laser displays the bounds of the artwork on the wall to verify the precise position of the print. In case of malfunction or danger printing can be paused anytime.
A balltower conveys the gelatin encapsulated color balls to the marker, which accelerates each ball to a speed of 200km/h, causing it to burst on contact with the wall and leave a color dot five to ten centimeters in diameter. The cracked gelatin shells fall to the ground where they can be removed or left to decompose naturally. The color in paintballs can differ considerably with regard to UV stability or dripping characteristics. Thus the printer can be used to create works which fade within a few hours or remain visible for several months.
Outdoor Device
For easy transport, the Facadeprinter can be closed into a handy case weighing 7,5 kg with dimensions 31 x 27 x 22cm. The amount of paint needed may vary depending on the application domain. To accommodate this variance, the ball tower and compressed air bottle are separate items which can be chosen to fit the current application. On location both can be connected to the printer easily via plug connectors.