3D printer arrives at Wrangell High School

Wrangell vocational and technical students could soon have a hands-on glimpse of the manufacturing future.

A 3D printer arrived at the high school shop last week, part of a Department of Labor-sponsored program at Sitka High School to move high technology into Southeast, according to high school shop teacher Drew Larrabee.

The printer consists of a small nozzle, resembling a glue gun, for extruding molten plastic onto a heated platform. The first thing the printer creates for each object is a small backing plate called a raft. Using software called Rhino-CAD, the printer then sprays successive thin layers of molten plastic in the shape of the design, until the design is completed. Using this method, the printer is able to manufacture plastic models of astonishing intricacy on demand, according to Larrabee.

For example, Larrabee and freshman Alisa Heller, who participated in training for the software in Sitka earlier in the year, have printed pieces which will eventually be assembled into a toy robot.

"The idea behind these machines is rapid prototyping," he said. "You're able to take something three-dimensional from the computer ... and you can print it out and make a model of what it is that you want."

That ability means students can draft replacement parts for engines or other things themselves, then use those models to mesh their design with real world applications, Larrabee said.

"The plastic isn't a terribly heavy gauge," he said. "It's pretty structurally solid, but you can mock it out and try it and see how it works."

A variety of companies already exist to manufacture the prototype into a usable part, Larrabee said.

"You can ask them to cast it in plastic, make it in metal," he said. "You can have the part made in just about any material you can think of and they'll charge you just for the manufacturing cost rather than the design cost."

That in itself represents a shift in the balance of power from the traditional manufacturing model, where big companies mass produce objects of their own design for consumers, to a consumer-demand oriented manufacturing model. The printers are also capable of severely reducing costs for more elaborate manufactured items.

For example, a man born without a right hand replaced his $42,000 traditionally manufactured prosthetic with a 3D printed prothesis. The design for the hand was free and the total materials cost was approximately $50, according to 3ders.org, a website which tracks trends in 3D printing. Students in Kansas City designed and printed a cap for ketchup squirt bottles which eliminates that annoying first squirt of watery ketchup out of ketchup squeeze bottles, according to the website.

For now, teachers are putting the printer through its paces and intend to integrate it more firmly into school curricula next year, Larrabee said. Among the more eye-catching objects they've produced is a seven-layer set of enclosed polyhedrons, printed together as a single object. The process of learning the ins and outs of the new machine are full of trial and error, Larrabee said.

"What we're learning is you can't take someone's design off the Internet and print it out," he said.

For example, they downloaded and scaled down a set of interlocking gears, known as a planetary gear, to match the smaller size of the high school's printer.

"The outside gears worked fine, but the smaller ones on the inside don't work," he said.

Instead, they printed each piece separately and then assembled the final product together.

The printer is only the most novel device in a raft of new machines potentially making their way to the Wrangell High shop department. The department has also applied for a laser cutter, and a CNC (computer numerical control) router for woodworking, in addition to new computers. Larrabee is also considering a joint program with the borough government for high school shop classes to produce public signage at only the cost of materials.

The department's overall push is to match student skills with demands for Wrangell's developing maritime industry, Larrabee said. A local contractor recently purchased a CNC plasma cutter to use for making boat parts, only to discover that few people knew how to use it, Larrabee said.

Marine jobs could provide a route to employing more Wrangellites locally, rather than losing them to jobs in the lower 48 or elsewhere in Alaska, Larrabee said.

"Our Marine Center and our industry in town is growing with this demand," he said. "These guys would love to upgrade to this new technology, but nobody has had that training."

Heller has so far made a plastic die and a slinky, though she wasn't sure yet what she would make given some time alone with the printer.

Another student had at least one idea.

"You could make a phone case," said junior Jeffrey Rooney.

"That would be a really good idea," Heller said.