Day: February 9, 2017

Modular Portable Conveyor Belt

February 9, 2017 by 11 Comments

When teaching Industrial Automation to students, you need to give them access to the things they will encounter in industry. Most subjects can be taught using computer programs or simulators — for example topics covering PLC, DCS, SCADA or HMI. But to teach many other concepts, you  need to have the actual hardware on hand to be able to understand the basics. For example, machine vision, conveyor belts, motor speed control, safety and interlock systems, sensors and peripherals all interface with the mentioned control systems and can be better understood by having hardware to play with. The team at [Absolutelyautomation] have published several projects that aim to help with this. One of these is the DIY conveyor belt with a motor speed control and display.

This is more of an initial, proof of concept project, and there is a lot of room for improvement. The build itself is straightforward. All the parts are standard, off the shelf items — stuff you can find in any store selling 3D printer parts. A few simple tools is all that’s required to put it together. The only tricky part of the build would likely be the conveyor belt itself. [Absolutelyautomation] offers a few suggestions, mentioning old car or truck tyres and elastic resistance bands used for therapy / exercise as options.

If you plan to replicate this, a few changes would be recommended. The 8 mm rollers could do with larger “drums” over them — about an inch or two in diameter. That helps prevent belt slippage and improves tension adjustment. It ought to be easy to 3D print the add-on drums. The belt might also need support plates between the rollers to prevent sag. The speed display needs to be in linear units — feet per minute or meters per minute, rather than motor rpm. And while the electronics includes a RS-485 interface, it would help to add RS-232, RS-422 and Ethernet in the mix.

While this is a simple build, it can form the basis for a series of add-ons and extensions to help students learn more about automation and control systems. Or maybe you want a conveyor belt in your basement, for some reason.

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Living High-Altitude Balloon

February 9, 2017 by 25 Comments

High-altitude balloons are used to perform experiments in “near space” at 60,000-120,000 ft. (18000-36000m). However, conditions at such altitude are not particularly friendly and balloons have to compete with ultraviolet radiation, bad weather and the troubles of long distance communication. The trick is to send up a live entity to make repairs as needed. A group of students from Stanford University and Brown University repurposed nature in their solution. Enter Bioballoon: a living high-altitude research balloon.

Instead of using inorganic materials, the Stanford-Brown International Genetically Engineered Machine (iGEM) team designed microbes that grow the components required to build various tools and structures with the hope of making sustained space research feasible. Being made of living material, Bioballoon can be grown and re-grown with the same bacteria, lowering the cost of manufacturing and improving repeatability.

Bioballoon is engineered to be modular, with different strains of bacteria satisfying different requirements. One strain of bacteria has been modified to produce hydrogen in order to inflate the balloon while the balloon itself is made of a natural Kevlar-latex mix created by other cells. Additionally, the team is using Melanin, the molecule responsible for skin color and our personal UV protection to introduce native UV resistance into the balloon’s structure. And, while the team won’t be deploying a glider, they’ve designed biological thermometers and small molecule sensors that can be grown on the balloon’s surface. They don’t have any logging functionality yet, but these cellular hacks could amalgamate as a novel scientific instrument: cheap, light and durable.

Living things too organic for your taste? Don’t worry, we’ve got some balloons that won’t grow on you.

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Iron Man, In IRON!

February 9, 2017 by 28 Comments

Sometimes a project comes our way which has so much information contained in it as to be overwhelming, and on which it is difficult to know where to start. A good example is [Barry Armstead]’s Iron Man suit, to which we were introduced through a very long forum thread that spans several years.

Home-made armour is a staple of the cosplay world, with many astoundingly good creations being produced by fans. What makes [Barry]’s Iron Man suit stand out from the crowd is its construction; instead of fiberglass or vacuum-formed plastic he’s used real metal. (It’s steel. But steel contains iron, right? We’re calling poetic license.)

The best place to follow progress on the suit is probably [Barry]’s YouTube feed, in which he has so far racked up 44 build logs. We see joint articulation tests, early test walks, the iconic helmet taking shape, and the repulsor simulated with a nano sprayer. With so many videos to watch, you’ll be there quite a while. The one we’ll leave you with below the break is fairly straightforward, the first look at the entire exoskeleton in bare metal.

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Soviet Era Smoke Detector Torn Down, Revealing Plutonium

February 9, 2017 by 50 Comments

It’s widely known that a smoke detector is a good ionizing radiation source, as they contain a small amount of americium-241, a side product of nuclear reactors. But what about other sources? [Carl Willis] got hold of an old Soviet era smoke detector and decided to tear it down and see what was inside. This, as he found out, isn’t something you should do lightly, as the one he used ended up containing an interesting mix of radioactive materials, including small amounts of plutonium-239, uranium-237, neptunium-237 and a selection of others. In true hacker fashion, he detected these with a gamma ray spectroscope he has in his spare bedroom, shielded from other sources with lead bricks and copper and tin sheets. Continue reading “Soviet Era Smoke Detector Torn Down, Revealing Plutonium” →

Correct Horse Battery Staple: The Book

February 9, 2017 by 88 Comments

XKCD 936, the comic that introduced the phrase, ‘correct horse battery staple’ into both the lexicon and password dictionaries, is the best way to generate a password. Your passwords should be random phrases of random words, hopefully with a few random numbers or symbols sprinkled about. It’s the most entropy you can get that’s also easy to remember.

However, generating your own ‘correct horse’ password is generally a bad idea. Humans are terrible at coming up with random bits of information. Thankfully, the EFF has come up with a wordlist containing 7,776 random words (65, or five rolls of a six-sided die.) ready for the next time you reset a password.

[m145mcc] thought the EFF’s word list should be a book, so he made it a book. With the clever application of a laser printer, glue, thread, and some card stock, [m145mcc] has a handy password generator that fits in his pocket. All that’s needed to build a password is a single die, a pen, and some patience.

The EFF’s random passphrase list is based off [Arnold Reinhold]’s Diceware list from 1995, but has a few changes to make the list easier to use and more palatable for the audience they’re going for. Most significantly, vulgar words were removed from the Diceware list, as the netsec crowd doesn’t swear as a rule. Additionally, numbers were removed, along with rare and unusual words. The passwords generated by the EFF’s list are longer, but they are arguably more memorable.

Despite the idea of a random dice-based password list being around for two decades, there are few if any examples of this list in dead tree format. The idea of a bound version of this list is a great idea, and we’re glad [m145mcc] could bring it to the table.

Good In A Pinch: The Physics Of Crimped Connections

February 9, 2017 by 123 Comments

I had a friend who was an electronics assembly tech for a big defense contractor. He was a production floor guy who had a chip on his shoulder for the engineers with their fancy book-learnin’ who couldn’t figure out the simplest problems. He claimed that one assembly wasn’t passing QC and a bunch of the guys in ties couldn’t figure it out. He sidled up to assess the situation and delivered his two-word diagnosis: “Bad crimp.” The dodgy connector was re-worked and the assembly passed, much to the chagrin of the guys in the short-sleeved shirts.

Aside from the object lesson in experience sometimes trumping education, I always wondered about that “bad crimp” proclamation. What could go wrong with a crimp to so subtly futz with a circuit that engineers were baffled? How is it that we can rely on such a simple technology to wire up so much of the modern world? What exactly is going on inside a crimped connection anyway?

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Seiko Spring Drive Movement Being Assembled

Keeping Time With A Spring Powered Integrated Circuit

February 9, 2017 by 16 Comments

Watch aficionados have a certain lust for mechanical watches. These old school designs rely on a spring that’s wound up to store energy. The movement, an intricate set of gears and other mechanical bits, ensures that the hands on the watch face rotates at the right speed. They can be considered major feats of mechanical engineering, with hundreds of pieces in an enclosure that fits on the wrist. They’re quite cheap, and you have to pay a lot for accuracy.

Quartz watches are what you usually see nowadays. They use a quartz crystal oscillator, usually running at 32.768 kHz. These watches are powered by batteries, and beat out their mechanical counterparts for accuracy. They’re also extremely cheap.

Back in 1977, a watchmaker at Seiko set off to make a mechanical watch regulated by a quartz crystal. This watch would be the best of both words. It did not become a reality until 1997, when Seiko launched the Spring Drive Movement.

A Blog To Watch goes through the design and history of the Spring Drive movement. Essentially, it uses a super low power integrated circuit, which consumes only 25 nanowatts. This IC receives power from the wound up spring, and controls an electromagnetic brake which allows the movement to be timed precisely. The writeup gives a full explanation of how the watch works, then goes through the 30 year progression from idea to product.

Once you’ve wrapped your head around that particularly awesome piece of engineering, you might want to jump into the details that make those quartz crystal resonators so useful.

[Thanks to John K. for the tip!]