Prusa Advises On Printed Medical Devices, Releases Face Shield

March 20, 2020 by 37 Comments

Like everyone else, hackers and makers want to do something to help control the spread of COVID-19. The recent posts on Hackaday dealing with DIY and open source approaches to respirators, ventilators, and masks have been some of the most widely read and commented on in recent memory. But it’s important to remember that the majority of us aren’t medical professionals, and that even the most well-meaning efforts can end up making things worse if they aren’t done correctly.

Which is exactly what [Josef Průša] wanted to make clear about 3D printed medical equipment in his latest blog post. Like us, he’s thrilled to see all the energy the maker community is putting into brainstorming ways we can put our unique skills and capabilities to use during this global pandemic, but he also urged caution. Printing out an untested design in a material that was never intended for this sort of application could end up being more dangerous than doing nothing at all.

The nested design lends itself to mass production.

To say that he and his team are authorities in the realm of fused deposition modeling (FDM) would be something of an understatement. They know better than most what the technology is and is not capable of, and they’re of the opinion that using printed parts in respirators and other breathing devices isn’t viable until more research and testing is done

For example, how can we ensure the porous plastic parts are sterilized and not just serving as a breeding ground for bacteria? It’s hardly a new concern; the debate about printed objects in food contact applications has been going on for years.

The safest option is to only use printed parts for structural components that don’t need to be sterile. To that end, [Josef] used the post to announce a newly published design of a printable face shield for medical professionals. Starting with an existing open source design, the Prusa Research team used their experience to optimize the headband for faster and easier printing. They can produce four headbands at once on each of the printers in their farm, which will allow them to make as many as 800 shields per day without impacting their normal business operations. The bottleneck on production is actually how quickly they can cut out the clear visors with their in-house laser, not the time it takes to print the frames.

It’s easy to get excited when success stories featuring 3D printed medical devices are in the news, but that doesn’t mean you should be cranking out lifesaving devices with that roll of bargain PLA you’ve had sitting around the shop. As difficult as it may be for some of us to admit, the safest thing might be to let our spare CPU cycles do battle with COVID-19 instead.

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This Week In Security: Working From Home Edition

March 20, 2020 by 8 Comments

As the world sits back and waits for Coronavirus to pass, the normally frantic pace of security news has slowed just a bit. Google is not exempt, and Chrome 81 has been delayed as a result. Major updates to Chrome and Chrome OS are paused indefinitely, but security updates will continue as normal. In fact, Google has verified that the security related updates will be packaged as minor updates to Chrome 80.

Chinese Viruses Masquerading as Chinese Viruses

Speaking of COVID-19, researchers at Check Point Research stumbled upon a malware campaign that takes advantage of the current health scare. A pair of malicious RTF documents were being sent to various Mongolian targets. Created with a tool called “Royal Road“, these files target a set of older Microsoft Word vulnerabilities.

This particular attack drops its payload in the Microsoft Word startup folder, waiting for the next time Word is launched to run the next stage. This is a clever strategy, as it would temporarily deflect attention from the malicious files. The final payload is a custom RAT (Remote Access Trojan) that can take screenshots, upload and download files, etc.

While the standard disclaimer about the difficulty of attribution does apply, this particular attack seems to be originating from Chinese intelligence agencies. While the Coronavirus angle is new, this campaign seems to stretch back to 2017.
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Pop A Wheelie With Your Electric Skateboard, The Hacker Way

March 20, 2020 by 9 Comments

Using a bit of tech to make up for a lack of skill is a time-honoured tradition, otherwise known as cheating among those who acquired the skill the hard way. Learning to wheelie manual a skateboard is usually paid for in bruises, but [blezalex] got around that by letting his electric skateboard handle the balancing act.

At first glance the board looks and rides like an average DIY electric skateboard, with an off-the-shelf  a dual hub motor truck, VESC speed controllers and a wireless throttle. The party trick appears when the front wheel is popped off the ground, which activates the secret self-balancing mode. At this point a STM32F401 dev board and MPU-6050 IMU take over control of the motors, which is in turn controlled by leaning forward or backwards, like a hoverboard. The remote throttle turns into a dead man switch, which cuts power to the motors when released.

[blezalex] says he has had less that an hour of skateboard time in his life before getting on this one, which is a good testament of just how well it works. The biggest challenge was in getting the board to turn while on two wheels, which was solved by sensing side-to-side tilt of the board with the IMU and applying proportional differential torque to the wheels. With a bit of practice it’s also possible to smoothly shift between riding modes while moving.

We think this is a really elegant cheat, now we need to build one of our own. Fortunately the STM32 firmware and instructions are all up on GitHub. Building your own electric skateboard has become really simple with the availability of off-the-shelf components. We’ve also seen a bicycle with a wheelie cheat device to prevent you falling on your back

“Glixie” Puts A New Spin On Glow-In-The-Dark Displays

March 20, 2020 by 4 Comments

For as many projects as we see using Nixie tubes in new and unusual ways, there’s a smaller but often very interesting cohort of displays that fit into the “Nixie-like” category. These are projects where something other than the discharge of noble gasses is being used to form characters. This scrolling phosphorescent single-character display is one such project, and we think it looks fabulous.

Following the *ixie naming convention characteristic of these builds, [StephenDeVos] dubbed this the “Glixie.” This is on par with the size of a [Dalibor Farny] handmade Nixie, but not so big to be unwieldy. The display modality is glow-in-the-dark film that rotates past a vertical string of UV LEDs, which light up in turn as the cylinder rotates, building up the dot-matrix character column by column. There’s some fading of the first column by the time the whole character is built up, but not enough to be objectionable. We like the whole build, with laser-cut wood and the brass and steel hardware. Check it out in the video below.

If this phosphorescent display strategy seems familiar, it’s because we’ve seen it before. Remember this persistence of phosphorescence display? Or perhaps this time-writing robot clock? It’s not a new idea, but [Stephen]’s execution can’t be beat.

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An Armored Vehicle From Foam Core And Big Box Toys

March 19, 2020 by 7 Comments

Over the last several months, [Eric Strebel] has been working on a concept for an electric-powered infantry combat vehicle. We don’t think he’s been contracted by any nation’s military to design this vehicle, but as a product designer we imagine he does this sort of thing to keep himself sharp. In any event, it’s been fun to watch from the sidelines.

In the latest installment in this series of videos, [Eric] turns his earlier concept art into a functional prototype; albeit at somewhat reduced scale. Still, building any kind of vehicle from the ground up is no easy feat and it’s fascinating to watch the process.

The futuristic faceted look of the vehicle’s armor plate makes for an exceptionally time-consuming build, as he has to cut and glue each piece of foam core into place. Some of the smaller pieces seem to have the tell-tale char marks from a trip through the laser cutter, but in the video after the break you can see that the larger panels are hand cut with a razor.

The plan was originally to just make a static mock-up of the vehicle, but thanks to a pair of remote controlled trucks that [Eric] found at this local Big Box retailer, this foam fighter ended up getting an upgrade. After liberating the motors and gearboxes from the two trucks, he 3D printed axle extensions to take into account the wider track of his vehicle, and built his “tub” around it. While the R/C gear is clearly on the low end of the spectrum, the overall effect looks great as the vehicle is bounding around the yard.

Readers of Hackaday will no doubt be well aware of [Eric Strebel] and his many talents. From 3D scanning via photogrammetry to embedding electronics into flexible molded parts, you’re sure to learn something new from following this prolific maker.

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Rubber Bands Can Secure Your Sanity

March 19, 2020 by 4 Comments

One of the greatest joys of being a child was figuring out that rubber bands make awesome sounds when they are plucked, and that the sound is easily changed by stretching the band to different lengths. For those of us who need firsthand experience to truly understand how the world works, these types of self-discovery are a pretty great way to learn about physics.

If you’re looking to build a physical music lesson or musical physics lesson into your burgeoning home school curriculum, look no further than the junk drawer, the broom closet, and the 3D printer. [Ham-made] used to stretch his bands across an empty tissue box, but came up with a much more professional implementation based on a broom handle. Check out this fat sound!

You don’t even need to find a spare broom handle, because none of this is permanent — the headstock piece with the hooks is meant to slide up and down to create cool sounds, and the tailpiece threads on in place of the broom bristles. Inside the tailpiece is a piezo disk and a 1/4″ jack so you can plug it in to your amp stack and start an impromptu jazz group. Just keep it under 10 people, okay?

You’ll need to mic your chanteuse, so keep the physics fun going with this plastic cup microphone.

Baby Keyboard Is Really Three Boards

March 19, 2020 by No comments

Just when we think we’ve peeped all the cool baby keebs out there, another think comes along. This bad boy built by [andyclymer] can be configured three different ways, depending on what kind of control you’re after.

As designed, the PCB can be used as a six-switch macro keyboard, or a rotary encoder with two switches, or a pair of rotary encoders. It’s meant to be controlled with Trinket M0, which means it can be programmed with Arduino or CircuitPython.

This could really only be cooler if the key switch PCB holes had sockets for hot-swapping the switches, because then you could use this thing as a functional switch tester. But hey, you can always add those yourself.

If you’re in the market for purpose-built add-on input device, but either don’t have the purpose nailed down just yet, or aren’t sure you want to design the thing yourself, this board would be a great place to start. Usually, all it takes is using someone else’s design to get used to using such a thing, at which point it’s natural to start thinking of ways to customize it. [andyclymer] is selling these boards over on Tindie, or you can roll your own from the repo.

Need just a few more inputs? We’ve got you covered.