Who among us hasn’t dreamed of having some brainstorm idea, prototyping it, and then have some huge company put it into worldwide production? The problem is, that’s not really as easy as it sounds in most cases. Take the case of Robert Kearns. Never heard of him? You use the result of one of his patents pretty often; Kearns invented the intermittent windshield wiper.
If he had sold the patent to one of the big carmakers, this would be a short article. Not that he didn’t try. But it didn’t go very well and while, in the end, he prevailed, it was a very expensive victory.
The coolest stories from the hacker community this year are the rapid manufacturing efforts that have gone on in response to COVID-19. But [Mark Rehorst], frequently featured on these pages for his clever takes on 3D printing, shared a couple of really useful prints that are out of the ordinary for what we’ve been seeing: bias tape folders and ear savers.
Tailors around the world have threaded the needle on grass-roots face mask production. One of the more labor intensive parts of sewing a face mask is the fastening mechanism. With elastic straps, the size of the loops needs to be just right, but when you run out of elastic you need to sew straps. Bias tape is a popular material for that, but it’s finicky to fold and hold it for sewing.
[Mark] heard of the need and grabbed a bias tape folder design from Thingiverse. These work kind of like a zipper, pulling in the unfolded tape on one side and feeding it out the other, folded nicely for the needle and thread to take over. But of course he did one better, refining the original design to use less plastic to get more parts, faster, with less material use — win, win, win.
Speaking of those mask straps, it turns out the backs of your ears don’t like being rubbed raw for back-to-back-to-back 12-hour shifts at the hospital. We’ve seen health workers, themselves skilled hackers, recommend sewing buttons onto a headband to hold the mask straps.
Button/Headband earsaver
3D-printed earsaver
Mark’s revised earsaver design
But the 3D-printing world has an “earsaver” that provides a series of hooks on a plastic band that loops behind your head. Once again, [Mark] iterated on the standard design, finding ways to reduce material use while also fitting more units onto a single printer bed.
These functional prints are glamorous in their own ways. We love seeing hard-working 3D-printed items, but we love it even more when we see them getting better and better with each new version. The back story and the design files for the improved versions are available on his project writeup. Go [Mark]!
When you think of robots that were modeled after animals, a brittle star is probably not the first species that comes to mind. Still, this is the animal that inspired [Zach J. Patterson] and his research colleagues from Carnegie Mellon University for their underwater crawling robot PATRICK.
PATRICK is a soft robot made from molded silicone. Each of his five limbs contains several shape memory alloy (SMA) springs which can be contracted through Joule heating thereby causing the limbs to bend. The robot’s control board is sending and receiving commands via Bluetooth Low Energy from a nearby computer. To control PATRICK’s motion the researchers constructed a closed-loop system where an offboard OpenCV based camera system is constantly tracking the robot. As shown in the video below with an average velocity of 1 cm/s, PATRICK’s movement is a bit sluggish but the system is supposedly very robust against uncertainties in the environment.
In the future [Zach J. Patterson et al.] would like to improve their design by giving the robot the ability to grasp objects. Ultimately, also the offboard camera should be replaced with onboard sensors so that PATRICK can navigate autonomously.
