WISRD Research & Engineering Journal

● Should we have legs fit through the base and platform? ● Have you worked with the type of clay that was bought? ● Can you describe the kiln at SMCHS? Approximate dimensions? ● When would we have access to the kiln? ● How long might the firing process take place? ● Is the kiln electric or gas?

● The University of Hong Kong described the procedure and settings that they used for their ceramic prints. Please comment on their procedure and let us know if these steps

seem reasonable and pertinent to our application. ○ University of Hong Kong Procedure/Settings ■ printed directly on kiln shelving material

■ used red terracotta clay ■ 6 mm extruder nozzle ■ 2.7 mm layer height ■ 0.5 mm/s to 17 mm/s extrusion speed ■ 6 mm surface and 11 mm for base layer width ■ doubled printing path ■ 65% solid infill ■ 22-degree angle tapered surface pattern ■ base dried for 2 days then flipped over to print legs on it ■ pieces stored vertically and rotated periodically for several days until bone dry ■ fired in kiln at 1125C ■ experienced 11% shrinkage à They said they are still working on relationships between scale, geometry, and type of clay to improve the structures. Mr. Conboy was unable to answer all of our questions because he had not worked on a project like this. However, he made the following recommendations: ● We fire the clay at a temperature between 4,000-5,000 o C. ● The firing time is a few hours, but most of this time is to heat up and cool down. Cone 6 (which we would be using) clay is considered a low fire clay. ● He warned us that our biggest problem would most likely be the moisture in our clay. Too much of it would cause cracking while drying as well as “exploding” in the kiln. ● He said it was best for us to let the clay dry for a full week before firing. ● He believes that once fired, the platform will not crack when it is put in water, but it will soak up water. However, soaking up water will not affect its strength, just make it heavier. 2.2 Specs on Clay and Kiln Shelf We are using porcelain clay, which is not gritty and minimizes nozzle clogging. Clay was obtained from Laguna Clay Co. and picked up in person by Joe Wise. The type was #16 ^6 Porcelain Moist Clay, Boxed. It is purchased in 50-pound blocks for approximately $50. Specifications for this clay are shown in Table 1.

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