Year: 2020

Retrotechtacular: Wire Splicing The Army Way

June 11, 2020 by 31 Comments

For those of us who started experimenting with electricity when we were very young, one of the essential first skills was learning how to twist wires together. It seems like there’s not much to learn, but after a few failed attempts with nothing but your fingers, you learned a few tricks that are probably still with you to this day. It’s not surprising, then, that there’s an official US Army way to twist wires together, as this Signal Corps training film from 1941 shows.

Considering that the Signal Corps had nearly 80 years of experience with wiring battlefield communications at the outbreak of World War II, their methods were pretty solid, as were their materials. The film mainly concerns the splicing together of rolls of type W110-B field wire, used by the Signal Corps to connect command posts to forward positions, observation posts, and the rear echelons. More often than not laid directly upon the ground, the wire had to be tough, waterproof, and conductive enough that field telephone gear would still work over long loop lengths. As such, the steel-reinforced, rubber-and-fabric clad cable was not the easiest stuff to splice. Where we might cringe at the stresses introduced by literally tying a conductor in knots, it was all part of the job for the wire-laying teams that did the job as quickly as possible, often while taking enemy fire.

The film also has a section on splicing a new line into an existing, in-service circuit, using a T-splice and paying careful attention to the topology of the knots used, lest they come undone under stress. It’s fascinating how much thought was put into something as mundane as twisting wires, but given the stakes, we can appreciate the attention to detail.

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A Beginner’s Guide To Lithium Rechargeable Batteries

June 11, 2020 by 42 Comments

Batteries were once heavy, awkward things, delivering only a limp amount of current for their size and weight. Thankfully, over time, technology has improved, and in 2020, we’re blessed with capable, high-power lithium polymer batteries that can provide all the power your mobile project could possibly need. There are some considerations one must make in their use however, so read on for a primer on how to properly use LiPos in your project!

So Many Types!

With the first commercial lithium-ion battery entering the market in 1991, the (nearly) 30 years since have seen rapid development. This has led to a proliferation of different technologies and types of battery, depending on construction and materials used. In order to treat your batteries properly, it’s important to know what you’ve got, so paying attention to this is critical. Continue reading “A Beginner’s Guide To Lithium Rechargeable Batteries” →

Knitting Machine Rebuild Takes It To The Next Level

June 11, 2020 by 6 Comments

Those of us who to textile work may own a sewing machine and even if we’re really into it and have the funds, an overlocker. But there’s another machine in that field that few of us will have, and that’s a knitting machine. These machines have a sliding carriage over a long array of needles, and even the cheaper ones are way more expensive than for example a pretty decent oscilloscope. [Irene Wolf] has a Passap E6000 computerised knitting machine that is by no means an inexpensive one, and she’s made significant improvement to it by giving it new brains, a new motor controller, and replacing the mechanical rear needle bed with a set of computerised ones from the front of another machine.

In her write-up she goes in depth into the arrangement of sensors and electromagnets that operate the machine. She started with a lot of inspiration from a project at Hackerspace Bamberg, but used all the available Passap sensors as inputs where they had used only one. She has two Arduino M0 boards handling the inputs and a Raspberry Pi with control and user interface, and has posted some videos of the system in action one of which we’ve placed below the break.

We probably wouldn’t have had the courage to fearlessly hack such a high-value machine, and we’re particularly impressed by the result. The write-up is particularly interesting not only for the work itself, but for the detailed insight it gives to the workings of these machines. The best news – she’s not finished and there will be more installments.

While you’re waiting for more, remember this is by no means the first hacked knitting machine we’ve brought you.

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Quantum Computing And The End Of Encryption

June 11, 2020 by 58 Comments

Quantum computers stand a good chance of changing the face computing, and that goes double for encryption. For encryption methods that rely on the fact that brute-forcing the key takes too long with classical computers, quantum computing seems like its logical nemesis.

For instance, the mathematical problem that lies at the heart of RSA and other public-key encryption schemes is factoring a product of two prime numbers. Searching for the right pair using classical methods takes approximately forever, but Shor’s algorithm can be used on a suitable quantum computer to do the required factorization of integers in almost no time.

When quantum computers become capable enough, the threat to a lot of our encrypted communication is a real one. If one can no longer rely on simply making the brute-forcing of a decryption computationally heavy, all of today’s public-key encryption algorithms are essentially useless. This is the doomsday scenario, but how close are we to this actually happening, and what can be done?

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Dexter The Companion Bot Wants To Give You Five

June 11, 2020 by 2 Comments

The main character of Dexter’s Laboratory is a genius child inventor who inspired a lot of fans to become makers and inventors in their own right. [Jorvon Moss] a.k.a. [Odd_Jayy] counts himself as one of them. A serial companion bot builder, his projects are constantly evolving. But every once in a while he pauses long enough to share construction details. Like how we can build our own monkey companion bot Dexter named after the cartoon.

A slightly earlier iteration of Dexter attended Hackaday Superconference 2019. Perched on [Odd_Jayy]’s back, Dexter joined in a presentation on companion bots. We’ve been a fan of his work since Asi the robot spider and several more robots have been posted online since. Recently at Virtually Maker Faire 2020, he joined [Alex Glow] and [Angela Sheehan] to talk about their respective experiences Making Companion Bots.

Sketchbook pages with Dexter concept drawings[Odd_Jayy] starts with sketches to explore how a project will look and act, striving to do something new and interesting every time. One of Dexter’s novelties is adding interactivity to companion bots. Historically people couldn’t do much more than just look at a companion bot, but Dexter can high five their fans! Sometimes the excited robot monkey ends up slapping [Odd_Jayy] instead, but they’re working through issues in their relationship. Everyone is invited to see rapid cycles of iterative improvements on Twitter and Instagram. As of this writing, a mini Dexter is underway with design elements similar to the “Doc Eyes” goggle project running in parallel. It’s always fun to watch these creations evolve. And by openly sharing his projects both online and off, [Odd_Jayy] is certainly doing his part to inspire the next wave of makers and inventors.

The Sound Of Silence: Speed Up Your Video Consumption

June 11, 2020 by 31 Comments

There’s a lot of interesting content produced on video these days. Invariably, though, when we post something some comments will appear lamenting that a video isn’t the most efficient way to disseminate technical information. We have mixed feelings. Some things benefit from being able to see, for example, a screencast. Some people like the human connection of seeing an instructor interact with a class instead of just reading. But we will admit that sometimes a video takes longer to watch, especially if it is full of pauses. Unsilence is a tool from [labmoellertim] that can fix that. The command line tool takes a video and strips out the parts that are silent. You can also use it as a Python library if you want to build your own tools using the technique.

If you’ve ever taken a class online, it isn’t uncommon to speed up a video so you can get through class faster. This works to a point, but removing or speeding up silent gaps means you don’t have to “listen faster.” Of course, you could still speed up the video, too.

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Control A Motor With A Touchpad

June 10, 2020 by 11 Comments

There are a surprising wealth of parts inside of old laptops that can be easily scavenged, but often these proprietary tidbits of electronics will need a substantial amount of work to make them useful again. Obviously things such as hard drives and memory can easily be used again, but it’s also possible to get things like screens or batteries to work with other devices with some effort. Now, there’s also a way to reuse the trackpad as well.

This build uses a PS/2 touchpad with a Synaptics chip in it, which integrates pretty smoothly with an Arduino after a few pins on the touchpad are soldered to. Most of the work is done on the touchpad’s built in chip, so once the Arduino receives the input from the touchpad it’s free to do virtually anything with it. In this case, [Kushagra] used it to operate a stepper motor in a few different implementations.

If you have this type of touchpad lying around, all of the code and schematics to make it useful again are available on the project page. An old laptop in the parts bin is sure to have a lot of uses even after you take the screen off, but don’t forget that your old beige PS/2 mouse from 1995 is sure to have some uses like this as well.

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