Salt dough was chosen initially because of its consistency and easiness to extrude. The salt dough can also be baked to harden. Clay was chosen as the desired printing material because of its long history as a traditional architectural building material, as well as its accessibility, and abundance. The air-dry clay is an oil-based clay that does not require firing. Given its properties, the layers of extrusions did not bond to one another and it was extremely brittle when dried. The CV90 clay is a mixture of porcelain and coarse sand produced in the RISD Ceramics department. The clay dries a light beige and fires to a clean white; it is extremely durable and provides a clean finished look. The layers of extrusion bind together throughout the drying and firing process. 

A Series of extruders were developed to eliminate complications as well as optimize the process of extruding clay and production. In our final design, an 18V DV Motor, gearbox and plunger system was taken from a Ryobi P310 caulking gun and rewired to an external control box consisting of an Arduino, a potentiometer to control speed, and a 3-way 6-pin toggle switch to reverse the plunger by reversing the current. By quantifying the speed of the motor, accuracy in controlling the bead size was achieved. The ABB IRB120 robotic arm was used as a 3-axis printer for the printing process.

Digital simulations were run on the DIVA, a plug-in for Rhinoceros, in order to draw conclusions regarding the interior lighting conditions assessing the required facade conditions and determine the design parameters. Specific to location, time and day of a year, daylight grid simulation taken at 3’ and daylight image visualizations were used to determine, in lumens, how much natural light the building received with and without the façade.