Model Building

Plaster Models

Patrick Sherwood assisting with depowdering the
Xochimilco model

Two 3D printers were used to build the plaster models: The small umbrella models were printed with a Z-Corp 310-plus printer. Restaurant Los Manantiales, the
shell for Cosmic Rays, Bacardi, and the
large Milagrosa models were printed with
a Z-Corp 810 printer located at the Port Authority of New York and New Jersey. These models could not have been built without the generosity of the Princeton University MAE department or the Port Authority.

The same general process was used to create each plaster model. First, students used the computer program Rhino to develop a rendering of a structure based on Candela’s drawings.  This rendering is sent to a 3D printer that builds the model in discrete layers of plaster powder and adhesive with a technology similar to that of paper and ink used by inkjet printers.
A mechanical arm sweeps a layer of powder over the build space and ejects a pattern of adhesive where the model is positioned. The process repeats until the model is complete. Once the model dries it is carefully excavated from the build space (bulk depowdering) by scooping/ brushing away the unbound powder in which it is submerged. Fine depowdering is achieved with an air gun. The model is strengthened with an epoxy and finished by painting with a white primer.

Photo Album
See how Ted built the Bacardí model.


Bacardí Model
Edward (Ted) Segal built a model of the Bacardí Rum Factory as it was when completed in 1960. Each of the three shells consists of a shell body, set back ribs, edge ribs, V-beams along the groin, and legs. Integrating the pieces smoothly so that the printer recognized the components as a single object was the most difficult step. Ted made test prints for areas where a number of components intersected to provide a visual check that the model was printing as expected. Once the computer model was complete, each of the three shell vaults was printed individually. Because the models were fragile prior to the application of epoxy, the shells were printed upside down, cradled by a support structure. After printing and epoxying the underside, Ted carefully and gently lifted and flipped over each model. This flip was the tensest moment of the process since the model was so fragile and it could easily break. Next, Ted applied epoxy to the top side of each model. Once the epoxy dried, he applied paint to give it a finished appearance.

Watch Ted and Patrick Sherwood build Bacardi plaster
model at the PANYNJ.







Photo Album
See how Ashley built the Milagrosa design concept model.

Photo Album
See how Ashley built the Milagrosa complete bay model.

Church of Our Lady of the Miraculous Medal (Milagrosa)
Some of the most captivating features of Milagrosa are the design concept for the basic form, the interior with the twisting columns, and the exterior scalloping ridge which serves a key structural function. To capture these aspects, Ashley Thrall created two separate exhibit models.  The first shows the design concept (as depicted in the drawing) which features the three stages that Candela used to arrive at this concept. The second features a larger, complete bay which allows the viewer to understand the experience of the interior and to see the detail of the scalloping ridge on the exterior. Computer renderings of these models were made and exported to a three-dimensional printer to build each form. The design concept model was printed at the School of Architecture with assistance from John Hunter. This printer uses a plastic material to form the model. A structure of wax supports the model while it hardens and is later melted away. The larger plaster bay was printed, like several other models in the exhibit, at the Port Authority.

Photo Album
See how the students built the plaster umbrella models.

Umbrellas:  Rio’s Warehouse and Mercado de Chiclayo
The team of students that worked on the umbrella models included undergraduate students Christin Holzer, Plamen Ivanov, Marianne Koch, and Kira Schiavello and graduate students Dallas Dissmore, Powell Draper, Sarah Halsey, Jesse Hindle, Jennifer Pazdon, and Emily
. Two sets of models were created: Rio’s Warehouse umbrellas which are tilted to permit light, and Mercado de Chiclayo umbrellas with varying height.  The umbrellas were modeled with the foundations so that the viewer can get a more complete understanding of the structure.

Photo Album
See how Eric, Kieran, and Jennifer built the Los Manantiales model.

Restaurant Los Manantiales
Eric Hui printed the restaurant one pedal at a time in the summer of 2007.  It took many trials and errors to determine how to print one pedal. The model appears to be very thin, but in the end it needed to be three times the thickness of the true scale (thinner versions would break during the depowdering stage). Once a pedal was printed, epoxied and hardened, Eric joined it to an adjacent pedal using epoxy and clamps. In the summer of 2008, Kieran Kelly-Sneed and Jennifer Pazdon placed a layer of fabric with epoxy for added strength, and then primed and painted the model.

Photo Album
See how Katie and Aaron built the Cosmic Rays model.

Cosmic Rays Laboratory
Katie Kelly built the supports, stiffening arches, and platform of Cosmic Rays from medium-density fiberboard (MDF). The supports and stiffening arches have very unique, elegantly curved shapes, which required using MAE department’s laser cutter. However, the scale of the model required a thickness of MDF incompatible with the laser cutter’s ability, so the shapes were etched into the wood with the laser and then cut using a band saw. The platform was too large for the laser cutter so its outline was printed (on paper) at the scale of the model, and then traced onto the MDF and cut with a band saw. The pieces were assembled and glued together with wood glue, and sanded and patched with wood filler to give the appearance of a monolithic concrete structure. The thin concrete saddles were made using the 3-D printer at the Port Authority. Aaron Friedenberg glued the shell to the wooden arches and smoothed imperfections with wood filler.  He then sanded the whole shell surface to give it a smooth appearance. Finally a spray paint was applied.