Hackaday Podcast 016: 3D Printing With Steel, Molding With Expanded Foam, QUIP-Package Parts, And Aged Solder

April 26, 2019 by Mike Szczys 3 Comments

Join Editors Elliot Williams and Mike Szczys to recap the week in hardware hacking. This episode looks at microfluidics using Shrinky Dinks, expanding foam to build airplane wings, the insidious effect of time on component solder points, and Airsoft BBs used in 3D printing. Finishing out the episode we have an interview with two brothers who started up a successful business in the Shenzhen electronics markets.

Take a look at the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Direct download (60 MB or so.)

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Retrotechtacular: Balloons Go To War

April 25, 2019 by Tom Nardi 5 Comments

To the average person, the application of balloon technology pretty much begins and ends with birthday parties. The Hackaday reader might be able to expand on that a bit, as we’ve covered several projects that have lofted various bits of equipment into the stratosphere courtesy of a high-altitude balloons. But even that is a relatively minor distinction. They might be bigger than their multicolored brethren, but it’s still easy for a modern observer to write them off as trivial.

But during the 1940’s, they were important pieces of wartime technology. While powered aircraft such as fighters and bombers were obviously more vital to the larger war effort, balloons still had numerous defensive and reconnaissance applications. They were useful enough that the United States Navy produced a training film entitled History of Balloons which takes viewers through the early days of manned ballooning. Examples of how the core technology developed and matured over time is intermixed with footage of balloons being used in both the First and Second World Wars, and parallels are drawn to show how those early pioneers influenced contemporary designs.

Even when the film was produced in 1944, balloons were an old technology. The timeline in the video starts all the way back in 1783 with the first piloted hot air balloon created by the Montgolfier brothers in Paris, and then quickly covers iterative advancements to ballooning made into the 1800’s. As was common in training films from this era, the various “reenactments” are cartoons complete with comic narration in the style of W.C. Fields which were designed to be entertaining and memorable to the target audience of young men.

While the style might seem a little strange to modern audiences, there’s plenty of fascinating information packed within the film’s half-hour run time. The rapid advancements to ballooning between 1800 and the First World War are detailed, including the various instruments developed for determining important information such as altitude and rate of climb. The film also explains how some of the core aspects of manned ballooning, like the gradual release of ballast or the fact that a deflated balloon doubles as a rudimentary parachute in an emergency, were discovered quite by accident.

When the film works its way to the contemporary era, we are shown the process of filling Naval balloons with hydrogen and preparing them for flight. The film also talks at length about the so-called “barrage balloons” which were used in both World Wars. Including a rather dastardly advancement which added mines to the balloon’s tethers to destroy aircraft unlucky enough to get in their way.

This period in human history saw incredible technological advancements, and films such as these which were created during and immediately after the Second World War provide an invaluable look at cutting edge technology from a bygone era. One wonders what the alternative might be for future generations looking back on the technology of today.

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The $50 Ham: Dummy Loads

April 25, 2019 by Dan Maloney 41 Comments

This is an exciting day for me — we finally get to build some ham radio gear! To me, building gear is the big attraction of amateur radio as a hobby. Sure, it’s cool to buy a radio, even a cheap one, and be able to hit a repeater that you think is unreachable. Or on the other end of the money spectrum, using a Yaesu or Kenwood HF rig with a linear amp and big beam antenna to work someone in Antartica must be pretty cool, too. But neither of those feats require much in the way of electronics knowledge or skill, and at the end of the day, that’s why I got into amateur radio in the first place — to learn more about electronics.

To get my homebrewer’s feet wet, I chose perhaps the simplest of ham radio projects: dummy loads. Every ham eventually needs a dummy load, which is basically a circuit that looks like an antenna to a transmitter but dissipates the energy as heat instead of radiating it an appreciable distance. They allow operators to test gear and make adjustments while staying legal on emission. Al Williams covered the basics of dummy loads a few years back in case you need a little more background.

We’ll be building two dummy loads: a lower-power one specifically for my handy talkies (HTs) will be the subject of this article, while a bigger, oil-filled “cantenna” load for use with higher power transmitters will follow. Neither of my designs is original, of course; borrowing circuits from other hams is expected, after all. But I did put my own twist on each, and you should do the same thing. These builds are covered in depth on my Hackaday.io page, but join me below for the gist on a good one: the L’il Dummy.

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3D Printering: The Quest For Printable Food

April 24, 2019 by Tom Nardi 44 Comments

A video has been making the rounds on social media recently that shows a 3D printed “steak” developed by a company called NovaMeat. In the short clip, a machine can be seen extruding a paste made of ingredients such as peas and seaweed into a shape not entirely unlike that of a boot sole, which gets briefly fried in a pan. Slices of this futuristic foodstuff are then fed to passerby in an effort to prove it’s actually edible. Nobody spits it out while the cameras are rolling, but the look on their faces could perhaps best be interpreted as resigned politeness. Yes, you can eat it. But you could eat a real boot sole too if you cooked it long enough.

To be fair, the goals of NovaMeat are certainly noble. Founder and CEO Giuseppe Scionti says that we need to develop new sustainable food sources to combat the environmental cost of our current livestock system, and he believes meat alternatives like his 3D printed steak could be the answer. Indeed, finding ways to reduce the consumption of meat would be a net positive for the environment, but it seems his team has a long way to go before the average meat-eater would be tempted by the objects extruded from his machine.

But the NovaMeat team aren’t the first to attempt coaxing food out of a modified 3D printer, not by a long shot. They’re simply the most recent addition to a surprisingly long list of individuals and entities, not least of which the United States military, that have looked into the concept. Ultimately, they’ve been after the same thing that convinced many hackers and makers to buy their own desktop 3D printer: the ability to produce something to the maker’s exacting specifications. A machine that could produce food with the precise flavors and textures specified would in essence be the ultimate chef, but of course, it’s far easier said than done.

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Component Shelf Life: How To Use All That Old Junk

April 23, 2019 by Ted Yapo 31 Comments

There are two types of Hackaday readers: those that have a huge stock of parts they’ve collected over the years (in other words, an enormous pile of junk) and those that will have one a couple of decades from now. It’s easy to end up with a lot of stuff, especially items that you’re likely to use in more than one design; the price breakpoints at quantities of 10 or 100 of something can be pretty tempting, and having a personal stock definitely speeds the hacking process now that local parts shops have gone the way of the dinosaur. This isn’t a perfect solution, though, because some components do have shelf-lives, and will degrade in some way or another over time.

If your stash includes older electronic components, you may find that they haven’t aged well, but sometimes this can be fixed. Let’s have a look at shelf life of common parts, how it can be extended, and what you can do if they need a bit of rejuvenation.

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Hack My House: UL Certification And Turning The Lights On With An ESP8266

April 22, 2019 by Jonathan Bennett 48 Comments

It’s hard to imagine a smart house without smart lighting. Maybe it’s laziness, but the ability to turn a light on or off without walking over to the switch is a must-have, particularly once the lap is occupied by a sleeping infant. It’s tempting to just stuff a relay in the electrical boxes and control them with a Raspberry Pi or micro-controller GPIO. While tempting, get it wrong and you have a real fire hazard. A better option is one of the integrated WiFi switches. Sonoff is probably the most well known brand, producing a whole line of devices based on the ESP8266. These devices are powered from mains power and connect to your network via WiFi. One disadvantage of Sonoff devices is they only work when connected to Sonoff’s cloud.

Light switches locked in to a cloud provider are simply not acceptable. Enter Tasmota, which we’ve covered before. Tasmota is an open source firmware, designed specifically for Sonoff switches, but supporting a wide range of ESP8266 based devices. Tasmota doesn’t connect to any cloud providers unless you tell it to, and can be completely controlled from within a local network.

Certifications, Liability, and More

We’re well acquainted with some of the pitfalls of imported electronics, but one of the lesser known problems is the lack of certification. In the United States, there are several nationally recognized testing laboratories: Underwriters Laboratories (UL) and Intertek (ETL) are the most prominent. Many imported electronic devices, including Sonoff devices, do not have either of these certifications. The problem with this is liability, should the worst ever happen and an electrical fire break out. The Internet abounds with various opinions on the importance of the certification — a missing certification mark is somewhere between meaningless and a total hazard. The most common claim is that a house fire combined with non-certified equipment installed would result in an insurance company refusing to pay.

Rather than just repeat this surely sage advice from the Internet, I asked my insurance agent about uncertified equipment in the case of a fire. I discovered that insurance agencies avoid giving definite answers about claim payments. The response that came back was “it depends”: homeowner’s insurance covers events that are accidental and sudden. If a homeowner was aware that they were using uncertified equipment, then it could be categorized as “not an accident”. So far, the myth seems plausible. The final answer from the insurance agency: it’s possible that a non UL-certified device could result in denial of payment on a claim, but it depends on the policy and other details– why take the risk? Certification marks make insurance companies happier.

I also talked to my city’s electrical inspector about the issue. He commented that non-certified equipment is a violation of electrical code when it is hard-wired into a house. He echoed the warning that an insurance company could refuse to pay, but added that in the case of injury, there could be even further liability issues. I’ve opted to use certified equipment in my house. You’ll have to make your own decision about what equipment you’re willing to use.

There are some devices on Amazon that claim to have certification, but searching the certification database leads me to believe that not all of those claims are valid. If in doubt, there is a searchable UL database, as well as a searchable Intertek database.
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KiCad And FreeCAD Hack Chat

April 22, 2019 by Dan Maloney 4 Comments

Join us Wednesday at noon Pacific time for the KiCad and FreeCAD Hack Chat led by Anool Mahidharia!

The inaugural KiCon conference is kicking off this Friday in Chicago, and KiCad aficionados from all over the world are gathering to discuss anything and everything about the cross-platform, open-source electronic design automation platform. As you’d expect, Hackaday will have a presence at the conference, including a meet and greet after party. There’ll also be talks by a couple of our writers, including Anool Mahidharia, who’ll be taking time out of his trip to the States to drop by the Hack Chat with a preview of his talk, entitled “Fast 3D Model Creation with FreeCAD”.

Join us for the KiCad and FreeCAD Hack Chat this week with your questions about KiCad and FreeCAD. If you’ve got some expertise with electronic design tools, make sure you come by and contribute to the discussion too — we’d love to hear your insights. And as always, you can get your questions queued up by leaving a comment on the KiCad and FreeCAD Hack Chat event page and we’ll put them on the list for the Hack Chat discussion.

Our Hack Chats are live community events in the Hackaday.io Hack Chat group messaging. This week we’ll be sitting down on Wednesday, April 24, at noon, Pacific time. If time zones have got you down, we have a handy time zone converter.

Click that speech bubble to the right, and you’ll be taken directly to the Hack Chat group on Hackaday.io. You don’t have to wait until Wednesday; join whenever you want and you can see what the community is talking about.