So, what does the University of Washington, milk jugs, recreational boating and 3D Printing have in common? Not much… until now! The new ‘Washington Open Object Fabricator’ Group (WOOF), UW Engineering students and the Open 3D Printing Lab managed to manufacture a boat from shredded HDPE milk jugs and a hacked Plasma Cutter named ‘Big Red’. The aim? To manufacture an boat and compete in the 42nd Annual Milk Carton Derby. Here’s the story.
Hack a Plasma Cutter. Shred Milk Jugs. Print Away…
3D Printing on such a scale is not easy – HDPE is a finicky material; warpage, extrusion and low-speed meant long nights and a great deal of fretting.
Our process took a short while to evolve, but we found a great way to make the print turn out beautifully. We ran the printer at 30% speed. Adam sat at the end of the machine and controlled the rheostat so that too much HDPE was not extruded during turns. Brandon stood near the windows to replenish the hopper, screw down the pegboard if it began to buckle, and any other task that needed to be done. Matt and myself sat on either side of the printer and were responsible for “clean up”. When the extruder would lay a bead next to a cooled bead it would not fuse to the old one. In more technical terms: the fresh bead did not have enough thermal energy to melt the cooled adjacent one so would not fuse. To overcome this we supplied energy with a heat gun to bring the old bead up to a fuseable temperature. The finished pattern looks great.
According to their detailed blog, their 3D printer was so loud they had to run it during the night after everyone had departed the campus. The first few layers of the print had to be screwed down with a drill to prevent the whole boat from rolling up like a wilting leaf.
Of course, they managed to get their boat done in time for the Derby, but there were some more bumps on the road, some… bureaucratic mis-understandings. “We had some issues at the beginning as the Seafair crew didn’t know how to categorize our very unique boat.” Nevertheless, they were given the green light and won second prize! Damn impressive!
Certainly not the most elegant boat, but nobody up until now has tried to make a useable boat with a 3D printer (that I know of – perhaps Solidsmack readers might know of another). If you have a chance, peruse the WOOF (Washing Open Object Fabricators) blog and the Open 3D Printing lab’s website – they’ve been doing some amazing things out there.