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Apr
21
2021
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In recent years, 3D printing has become a big deal for us here at Gray. With 3D printing, we can build three-dimensional solid objects from digital files. There are countless applications for this technology, but we get especially excited about printing replicas of our fossils!
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This fossil turtle shell is gorgeous, but it’s also delicate and invaluable, so we 3D printed a two-toned duplicate for educational programs. The original stays safe in our collections where it can be studied, while the replica can be handled and admired by museum visitors.
3D printing fossil replicas is a process of many steps, and it starts with the fossils themselves. We need a digital model to send to the printer, so first we need to scan a fossil. For this, we typically use our pair of Artec scanners. These scanners, which look a bit like clothing irons, shine a laser light over the fossil while camera sensors measure the light as it reaches the fossil’s surface. After the scanner has gotten a good look at the whole fossil, we transfer all those laser-guided measurements to a computer, compile them with specialized software, and generate a digital model.
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Here’s Museum Specialist Keila Bredehoeft scanning a fossil rhino jaw while generating a digital model on the computer. In addition to scanners like this one, we sometimes use photogrammetry, a technique that generates digital models from photographs.
We upload many of our digital files to Sketchfab, where visitors can view and download our models.
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This is a model of one of our favorite fossil tapir skulls, available to view and download on our Sketchfab page.
Once they’re ready, our digital fossil files can be sent to the printer. As of this blog post, our museum has two active 3D printers, which handle most of our printing: a Prusa i3 MK3, with a build area of roughly 10 x 8 x 8 inches, and a Raise3D Pro2 Plus, which is a bit bigger at 12 x 12 x 24 inches. The smaller printer is the perfect size for printing fossil red panda skulls or musk turtle shells, while the bigger one can fit a whole tapir skull or slider turtle shell. Both printers work by laying down successive rows of PLA Plus filament, building the prints layer by layer. The end product is a lightweight, sturdy copy of a fossil.
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A small print might take a few hours to complete, but a big one can take a while! Even on our big printer, this rhino skull needed to be printed in three parts, and each part took multiple days!
In recent years, we’ve printed replicas of dozens of fossils from the Gray Fossil Site and beyond, including turtles, pandas, rhinos, and more. In the future, we’ll be using 3D-printing for the skeletons in our fossil exhibit hall, including a full-scale mastodon. Besides printing educational specimens, we’ve also used 3D printing to create custom lab equipment, to produce specially shaped cradles to hold our fossils, and even to help reassemble fossils in the prep lab.
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Some fossils are too small for our scanners. We sent this fossil garter snake vertebra (~5mm long) to be scanned at an Artec3D scanning facility in North Carolina, and we used the resulting digital model to print a giant-sized replica, big enough for museum visitors to hold and admire.
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In the prep lab, our mastodon skull is slowly being reassembled. Since one side of the face is more complete than the other, we scanned the complete side and printed a mirror-image to fit to the other side. These 3D printed prosthetics are built out of Butvar, the same material we use as glue for our fossils.
