Last summer a student organization based out of the University of Washington, WOOF (Washington Open Object Fabricators), successfully created the world’s first 3D Printed Boat. The boat was printed on a large-format Fused Deposition Modeling (FDM) printer, which was hacked together from a plasma cutter, and prints with post-consumer milk jugs.
The plasma cutter, known as “Big Red”, was donated to the group and converted into a printer with a massive 9 x 4 x 3 ft build area. The group had two months to get it functional and enter a boat into Seattle’s Annual Seafair Milk Carton Derby.
Milk jugs are made of High Density Polyethylene (HDPE), which despite being a fantastic material to make things out of, is not easy to print with. HDPE doesn’t adhere well to anything aside from hot HDPE and it shrinks substantially as it cools. To solve the first problem, the WOOF team built a unique build plate (pegboard with countersunk holes) to achieve a mechanical bond, and attached a heater to the extruder to soften the previous layer.
Printing quickly prevents the shrinking tendency of the plastic from becoming too much of a problem, but pausing the printing process for half a day allowed the walls of the boat to shift. The team ended up adjusting the CAD model in order to complete the print after the pause and printed a sacrificial flange with the boat, which was screwed into the bed, to further prevent warping.
The slideshow below includes a few images of the process:
The WOOF team is currently working on Version 2 of the boat for this summer’s competition, and they’ve made some improvements to the machine and the design. Instead of using pegboard for the build plate, they’re using a fused-HDPE surface, which already seems more promising. The boat itself will be printed in four sections, so the team can obtain the desired curvature for maximum performance.
A CAD model of Version 2 of the boat.
Thankfully, three WOOF members didn’t let their interest in large-format printing end there. Brandon Bowman, Bethany Weeks and Matt Rogge won techfortrade’s 3D4D Challenge in the Fall with a proposal to start a company that manufactures cheap, large-format (at least one meter cubed) FDM printers to aid developing areas. These areas will be able to print necessities like composting toilets by simply recycling their plastic waste as printing material in the machines.
Here’s hoping the Version 2 build goes smoothly and the WOOF team does well at the race in July!