At this point, we all have a mental image of a 3D printer: a basic box with a bed and extruder. Even with delta-style machines being somewhat common, the rectangular box concept dominates 3D printing. However, if you’ve been involved in the RepRap community or been to some of the bigger Maker Faires in the United States, you may have come across a display of interesting printer designs that, in comparison to the squarish Cartesian style, seem bizarre and unique. These are the works of Nick Seward.
Take the Wally (Figure A). This printer looks a lot like a cute robot printing onto its own belly. This is largely due to the SCARA (Selective Compliance Assembly Robot Arm) configuration, in which its arms move in an almost humanoid manner in the X- and Y-axes.
Then there’s the Wheelios (above), which also uses a SCARA arm, but this time mounted on a wheeled, rolling frame. It can, in theory, print indefinitely in one direction.
GUS Simpson is a spider-esque printer with three articulating “legs” that form the motion and the frame (Figure C). It’s a delta-type machine that undulates and flows in its entirety. The full effect is mesmerizing to watch: you can see it below.
Seward has physically built at least 13 unique designs and variations, and innumerable builds of individual machines. He often shares the full designs to the RepRap community.
Seward’s introduction to 3D printing came from exposure to a CNC mill at his first teaching job. He was instantly enamored, and endeavored to create his own. Seeing the fun he was having with this area of exploration, his wife purchased him a gift, one of the original wooden Printrbot 3D printers. A short period of printing the typical tchotchkes left Seward feeling a little empty, and he wanted to give back to the RepRap community.
Seward’s ensuing contributions have been fascinating and numerous. They also tend to have a theme of not being just boring iterations on the common box. Many, such as the Sextuperon (Figure D), require complicated software and electronics that are still being ironed out to this day. So why does he do it?
“At first, I told myself it was to save money and ultimately save others money. I think that was a lie,” he says. “I think I just enjoy designing using first principles and breaking conventional wisdom with engineering and science. The 3D printing maker movement is full of garage heroes. A side effect of having a large portion of the community without a formal education is a lot of common-sense knowledge that might not actually be true. I remember getting scoffed at for even proposing the idea of a printer that wouldn’t require rails.”
3D printers are still just a hobby for Seward. He is currently an instructor at the ASMSA school for the gifted in Arkansas, teaching computer science. But 3D printing finds its way into his classroom, and the results have been significant.
“At ASMSA, I love to get students involved in experimental projects that are at least 3D printing adjacent. The best infill pattern, cubic subdivision, was the brainchild of one of my students,” Seward says proudly. “Other software projects of note include a nonplanar slicer (rough prototype at this point), using Steiner trees to reduce support material, and compound bridging.”
What does Seward dream about? What big thing would he like to see come to fruition? “Long-term, I want to print a house,” he says. “There is no reason a few semi trucks with massive Simpson arms can’t roll up to a job site, connect, and print a house. It isn’t even a question of economics. Of course it will be cheaper to print a house. The two holdups are regulations and R&D costs. It is just a matter of time before the labor is expensive enough or the R&D cost is low enough to make this happen. Don’t get me wrong, there are people printing houses right now. I just want to see it go mainstream.”
After watching GUS Simpson in action, we want to see this too.
Open Source Extra: Leafhopper Legs
One of the most magical moments of open source collaboration led to the gear arms on GUS. “I had met [RepRap user]Guizmo in person in Texas,” says Seward. “He came up from Mexico and I made a trip to meet him and deliver beta parts for GUS Simpson. In the thread at reprap.org/forum/read.php?178,233674, Guizmo put forward what I thought was a horrible idea of Simpson arms. However, I used the ‘yes and’ approach. After half a dozen back and forths, he posted Figure E below.
It gave me the ‘aha’ I needed to get to the gear arms that GUS Simpson uses. Figure F is what I had three days later:
“It wasn’t that long after that Science came out about the leafhopper [insect] having gears like this too: cam.ac.uk/research/news/functioning-mechanical-gears-seen-in-nature-for-the-first-time. An amazing coincidence!”
Find Nick Seward’s machines, design files, and more at nickseward.net.
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