“Then Bryan Sieling, Chief of Design at NMAAHC, suggested that we speak with our colleagues in the Digitization Program office and Office of Exhibits Central who do 3D work,” said Dorey Butter, Project Manager, NMAAHC. “He called them, and they recommended Stratasys Direct Manufacturing.” Mick Schrempp, Account Manager, began a relationship with NMAAHC that facilitated the next steps.
“Many 3D laser scans were taken of the existing Monticello statue from different angles, pieced together and sent as a digital model,” Butter said. Once at Stratasys Direct Manufacturing, the computerized Jefferson was welcomed by Schrempp and Perry Hubbling, Project Engineer.
Schrempp knew that a thicker build slice would lessen the cost, as would a “sparse fill” concept, which he suggested to the team. “One of the main reasons the Smithsonian came to us was to reduce its costs,” said Hubbling. “Our main concern was to minimize the amount of support material during the build. That has a big influence on the build time and thus the cost. The outer wall of the statue is about .075 of an inch thick, he said. “The inside looks like a honeycomb.” The result is a lighter, yet very strong, model.
“The biggest challenge was figuring out where to split Jefferson, as the model was too large for even the largest Fortus 900 3D Production System,” said Hubbing. Stratasys Direct Manufacturing engineers recommended producing Thomas in four parts. They cut the CAD model in the middle of each of Jefferson’s thighs and in the middle of his chest. Later, pegs were used to bond him back together before being shipped to Washington. The Jefferson statue was created with a black, M-30 material because of its higher tensile strength.
“Secondary operations included sanding, a bronze fill finish, a few coats of a sand fill primer, additional sanding then gold paint,” said Vince Rossi, 3D Digitization Coordinator for the Smithsonian. “Then black wax was added to give it a bronze effect.”
Not many museums are doing work with rapid prototyping. If they are, it’s on a much smaller scale. My colleagues and I now evangelize about the technology and how it can support the Smithsonian mission to create touchable models and scientific replicas,” said Rossi.
The Jefferson project was one of the longest running jobs at Stratasys Direct Manufacturing, according to Hubbling. The total build time was 396 hours. Timing was important, as the statue needed to be ready for the opening of the exhibit, which will run from January 27 through October 14, 2012, in NMAAHC’s gallery at the Smithsonian National Museum of American History. “The process went smoothly, and we got what we wanted,” added Rossi.
“I was pleasantly surprised at the level of detail,” said Butter. I remember Elizabeth’s first comment when she saw the finished product. She said, ‘Oh my gosh, it looks just like him!’”
“This turned out to be the perfect solution,” added Butter, who said the Jefferson model may be used for educational purposes back at Monticello after the exhibit closes. “It was awesome. The technology has opened our eyes to different possibilities. This was much more than we had hoped for.”
