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Art of 3D printer in the middle of printing a Hackaday Jolly Wrencher logo

The Real Lessons About 3D Printed Face Shields: Effective Engineering Response In Times Of Crisis

April 8, 2020 by 83 Comments

3D printed face shields and other health equipment is big news right now. Not long ago, Prusa Research rapidly designed and manufactured 3D printed face shields and donated them to the Czech Ministry of Health. Their effort is ongoing, and 3D printers cranking out health equipment like the NIH approved design has been peppering headlines ever since.

The Important Part Isn’t 3D Printers

The implied takeaway from all the coverage is that 3D printers are a solution to critical equipment shortages, but the fact that 3D printers are involved isn’t really the important part. We all know printers can make plastic parts, so what should be the real takeaway? The biggest lessons we can learn about Prusa’s ongoing effort are related to how they’ve gone about it.

Continue reading “The Real Lessons About 3D Printed Face Shields: Effective Engineering Response In Times Of Crisis” →

On 5G And The Fear Of Radiation

April 8, 2020 by 178 Comments

The world around us is a scary place, with a lot of visible and invisible dangers. Some of those invisible dangers are pretty obvious, such as that of an electrical shock from exposed wiring. Some are less obvious, for example the dangers of UV radiation to one’s skin and eyes commonly known, but also heavily underestimated by many until it’s too late. In the US alone, skin cancer ends up affecting about one in every five people.

Perhaps ironically, while the danger from something like UV radiation is often underestimated, other types of electromagnetic radiation are heavily overestimated. All too often, the distinction between what is and isn’t considered to be harmful appears to be made purely on basis of whether it is ‘natural’ radiation or not. The Sun is ‘natural’, ergo UV radiation cannot be harmful, but the EM radiation from a microwave or 5G wireless transceiver is human-made, and therefore harmful. This is, of course, backwards.

Rather than dismissing such irrational fears of radiation, let’s have a look at both the science behind radiation and the way humans classify ‘danger’, such as in the case of 5G cell towers. Continue reading “On 5G And The Fear Of Radiation” →

Linux Fu: Tracing System Calls

April 7, 2020 by 11 Comments

One of the nice things about Linux and similar operating systems is that you can investigate something to any level you wish. If a program has a problem you can decompile it, debug it, trace it, and — if necessary — even dig into the source code for the kernel and most of the libraries the program is probably using. However, the tools to do this aren’t ones you use every day. One very interesting tool is strace. Using it you can see what system calls any program makes and that can sometimes give you important clues about how the program works or, probably more often, why it doesn’t work.

Let’s consider the least complex use of the command. Suppose you want to make symlink from testxmit.grc to the /tmp directory. That command is simple:

ln -sf testxmit.grc /tmp

But if you tell strace to run it, the command becomes:

strace ln -sf testxmit.grc /tmp

You might want to redirect the output to a file using the shell or the -o option, though. Some commands generate a lot and often the first page or two of output isn’t really what you care about anyway. Continue reading “Linux Fu: Tracing System Calls” →

Art of 3D printer in the middle of printing a Hackaday Jolly Wrencher logo

3D Printering: When Resin Printing Gets Smelly

April 7, 2020 by 20 Comments

Nowadays, resin printers are highly accessible and can do some great stuff. But between isopropyl alcohol for part rinsing and the fact that some resins have a definite smell to them, ventilation can get important fast. The manufacturers don’t talk much about this part of the resin printing experience, but it’s there nevertheless. So what can be done when smells become a problem?

I recently had to deal with this when I printed several liters of resin worth of parts. That’s a lot of resin, and a lot of alcohol for part washing. Smells — which had never been much of a problem in my work area — suddenly became an issue.

Where Odors Come From

Smells come from two sources: the resin itself, and the isopropyl alcohol used for cleanup and part washing. Continue reading “3D Printering: When Resin Printing Gets Smelly” →

Getting To Space Is Even Harder During A Pandemic

April 6, 2020 by 3 Comments

At this point, most of us are painfully aware of the restrictions that COVID-19 social distancing protocols have put on our daily lives. Anyone who can is working from home, major events are canceled, non-essential businesses are closed, and travel is either strongly discouraged or prohibited outright. In particularly hard hit areas, life and commerce has nearly ground to a halt with no clear end date in sight.

Naturally, there are far reaching consequences for this shutdown beyond what’s happening on the individual level. Large scale projects are also being slowed or halted entirely, as there’s only so much you can do remotely. That’s especially true when the assembly of hardware is concerned, which has put some industries in a particularly tight spot. One sector that’s really feeling the strain is aerospace. Around the world, space agencies are finding that their best laid plans are suddenly falling apart in the face of COVID-19.

In some cases it’s a minor annoyance, requiring nothing more than some tweaks to procedures. But when the movements of the planets are concerned, a delay of weeks or months changes everything. While things are still changing too rapidly to make an exhaustive list, we already know of a few missions that are being impacted in these uncertain times.

Continue reading “Getting To Space Is Even Harder During A Pandemic” →

Navigating Self-Driving Cars By Looking At What’s Underneath The Road

April 6, 2020 by 51 Comments

When you put a human driver behind the wheel, they will use primarily their eyes to navigate. Both to stay on the road and to use any navigation aids, such as maps and digital navigation assistants. For self-driving cars, tackling the latter is relatively easy, as the system would use the same information in a similar way: when to to change lanes, and when to take a left or right. The former task is a lot harder, with situational awareness even a challenge for human drivers.

In order to maintain this awareness, self-driving and driver-assistance systems use a combination of cameras, LIDAR, and other sensors. These can track stationary and moving objects and keep track of the lines and edges of the road. This allows the car to precisely follow the road and, at least in theory, not run into obstacles or other vehicles. But if the weather gets bad enough, such as when the road is covered with snow, these systems can have trouble coping.

Looking for ways to improve the performance of autonomous driving systems in poor visibility, engineers are currently experimenting with ground-penetrating radar. While it’s likely to be awhile before we start to see this hardware on production vehicles, the concept already shows promise. It turns out that if you can’t see whats on the road ahead of you, looking underneath it might be the next best thing. Continue reading “Navigating Self-Driving Cars By Looking At What’s Underneath The Road” →

Cellular Tracking Used During COVID-19 Pandemic

April 3, 2020 by 43 Comments

As most in the technology community know, nation states have a suite of powerful tools that can be used to trace and monitor mobile phones. By and large, this comes up in discussions of privacy and legislation now and then, before fading out of the public eye once more. In the face of a global pandemic, however, governments are now using these tools in the way many have long feared – for social control. Here’s what’s happening on the ground.

The Current Situation

With COVID-19 sweeping the globe, its high level of contagiousness and rate of hospitalizations has left authorities scrambling to contain the spread. Unprecedented lockdowns have been put in place in an attempt to flatten the curve of new cases to give medical systems the capacity to respond. A key part of this effort is making sure that confirmed cases respect quarantine rules, and isolate themselves to avoid spreading the disease. Rules have also been put in place in several countries where all overseas arrivals must quarantine, regardless of symptoms or status. Continue reading “Cellular Tracking Used During COVID-19 Pandemic” →