Mechanisms: Ode To The Zipper

January 26, 2018 by Dan Maloney 37 Comments

Look around yourself right now and chances are pretty good that you’ll quickly lay eyes on a zipper. Zippers are incredibly commonplace artifacts, a commodity item produced by the mile that we rarely give a second thought to until they break or get stuck. But zippers are a fairly modern convenience, and the story of their invention is one that shows even the best ideas can be delayed by overly complicated designs and lack of a practical method for manufacturing.

Try and Try Again

US Patent #504,307. One of the many iterations of Judson’s design. Like the others, it didn’t work.

Ideas for fasteners to replace buttons and laces have been kicking around since the mid-19th century. The first patent for a zipper-like fastener was issued to Elias Howe, inventor of the sewing machine. Though he was no slouch at engineering intricate mechanisms, Howe was never able to make his “Automatic, Continuous Clothing Closure” a workable product, and Howe shifted his inventive energies to other projects.

The world would wait another forty years for further development of a hookless fastener, when a Chicago-born inventor of little prior success named Whitcomb Judson began work on a “Clasp Locker or Unlocker.” Intended for the shoe and boot market, Judson’s device has all the recognizable parts of a modern zipper — rows of interlocking teeth with a slide mechanism to mesh and unmesh the two sides. The device was debuted at the Chicago World’s Fair in 1893 and was met with almost no commercial interest.

Judson went through several iterations of designs for his clasp locker, looking for the right combination of ideas that would result in a workable fastener that was easy enough to manufacture profitably. He lined up backers, formed a company, and marketed various versions of his improved products. But everything he tried seemed to have one or more serious drawbacks. When his fasteners were used in shoes, unexpected failure was a mere inconvenience. If a fastener on a lady’s dress opened unexpectedly, it could have been a social catastrophe. Coupled with a price tag that was exorbitantly high to cover the manual labor needed to assemble them, almost every version of Judson’s invention flopped.

Zipping up. Source: Dominique Toussaint (Wikipedia)

It would take another decade, a change of company name, a cross-country move, and the hiring of a bright young engineer before the world would have what we would recognize as the first modern zipper. Judson hired Gideon Sundback in 1901, and by 1913 he was head designer at the Fastener Manufacturing and Machine Company, newly relocated to Meadville, Pennsylvania after a stop in Hoboken, New Jersey. Sundback’s design called for rows of identical teeth with cups on the underside and nibs on the upper, set on fabric tapes. A slide with a Y-shaped channel bent the tapes to open the gap between teeth, allowing the cups to nest on the nibs and mesh the teeth together strongly.

Sundback’s design had significant advantages over any of Judson’s attempts. First, it worked, and it was reliable enough to start quickly making inroads into fashionable apparel beyond its initial marketing toward more utilitarian products like tobacco pouches. Secondly, and perhaps more importantly, Sundback invented machinery that could make hundreds of feet of the fasteners in a day. This gave the invention an economy of scale that none of Judson’s fasteners could ever have achieved.

Putting Some Teeth into It

Continuous process for forming metal zippers. Source: How Products Are Made

The machinery that Sundback invented to make his “Separable Fastener” has been much improved since the early 1900s, but the current process still looks similar, at least for metal zippers. Stringers, which are the fabric tapes with teeth attached, are formed in a continuous process by a multi-step punching and crimping machine. For metal stringers, a coil of flat metal is fed into a punch and die to form hollow scoops. The strip is then punched again to form a Y-shape around the scoop and cut it free from the web. The legs of the Y straddle the edge of the fabric tape, and a set of dies then crimps the legs to the tape. A modern zipper machine can make stringers at a rate of 2000 teeth per minute.

Plastic zippers are common these days, too, and manufacturing methods vary by zipper style. One method has the fabric tapes squeezed between the halves of a die while teeth are injection molded around the tape to form two parallel stringers. A sprue connected the stringers by the teeth breaks free after molding, and the completed stringers are assembled later.

Zippers have come a long way since Sundback’s first successful design, with manufacturing improvements that have eliminated many of the manual operations once required. Specialized zippers have made it from the depths of the oceans to the surface of the Moon, and chances are pretty good that if we ever get to Mars, one way or another, zippers will go with us.

The Current State Of The Black Market: You Can’t Buy Vantablack

January 25, 2018 by Zoe Skyforest 89 Comments

Sometimes you need something to be utterly, totally, irredeemably black. Not just a little bit black, not just really really really dark blue, but as black as it is possible to get. It might be to trap light in a camera or a telescope, for artistic purposes, or even to make your warplane a more difficult target for enemy missiles. Either way, we’re here to help, not to judge. So what are your options?

Well, first of all, there’s the much-lauded Vantablack. The name itself is a clue as to its origin – Vertically Aligned Nano Tube Arrays. It works by coating an object with a forest of carbon nanotubes in a complicated vacuum deposition process. When light hits the surface, some of it is absorbed by the nanotubes, and any that is reflected tends to be absorbed by neighbouring nanotubes rather than escaping the surface coating of the object.

Continue reading “The Current State Of The Black Market: You Can’t Buy Vantablack” →

Quantum Weirdness In Your Browser

January 24, 2018 by Al Williams 29 Comments

I’ll be brutally honest. When I set out to write this post, I was going to talk about IBM’s Q Experience — the website where you can run real code on some older IBM quantum computing hardware. I am going to get to that — I promise — but that’s going to have to wait for another time. It turns out that quantum computing is mindbending and — to make matters worse — there are a lot of oversimplifications floating around that make it even harder to understand than it ought to be. Because the IBM system matches up with real hardware, it is has a lot more limitations than a simulator — think of programming a microcontroller with on debugging versus using a software emulator. You can zoom into any level of detail with the emulator but with the bare micro you can toggle a line, use a scope, and hope things don’t go too far wrong.

So before we get to the real quantum hardware, I am going to show you a simulator written by [Craig Gidney]. He wrote it and promptly got a job with Google, who took over the project. Sort of. Even if you don’t like working in a browser, [Craig’s] simulator is easy enough, you don’t need an account, and a bookmark will save your work.

It isn’t the only available simulator, but as [Craig] immodestly (but correctly) points out, his simulator is much better than IBM’s. Starting with the simulator avoids tripping on the hardware limitations. For example, IBM’s devices are not fully connected, like a CPU where only some registers can get to other registers. In addition, real devices have to deal with noise and the quantum states not lasting very long. If your algorithm is too slow, your program will collapse and invalidate your results. These aren’t issues on a simulator. You can find a list of other simulators, but I’m focusing on Quirk.

What Quantum Computing Is

As I mentioned, there is a lot of misinformation about quantum computing (QC) floating around. I think part of it revolves around the word computing. If you are old enough to remember analog computers, QC is much more like that. You build “circuits” to create results. There’s also a lot of difficult math — mostly linear algebra — that I’m going to try to avoid as much as possible. However, if you can dig into the math, it is worth your time to do so. However, just like you can design a resonant circuit without solving differential equations about inductors, I think you can do QC without some of the bigger math by just using results. We’ll see how well that holds up in practice.

Continue reading “Quantum Weirdness In Your Browser” →

Build An Excellent Coffee Roaster With A Satisfyingly Low Price Tag

January 23, 2018 by Elliot Williams 62 Comments

There’s a lot of mysticism around coffee roasting, but in the end it couldn’t be simpler. Take a bunch of beans, heat them up evenly, and stop before they get burned. The rest is details.

And the same goes for coffee roasters. The most primitive roasting technique involves stirring the beans in a pan or wok to keep them from scorching on the bottom. This works great, but it doesn’t scale. Industrial drum roasters heat a rotating drum with ridges on the inside like a cement mixer to keep the beans in constant motion while they pass over a gas fire. Fluidized-bed roasters use a strong stream of heated air to whirl the beans around while roasting them evenly. But the bottom line is that a coffee roaster needs to agitate the beans over a controllable heat source so that they roast as evenly as possible.

My DIY coffee roaster gave up the ghost a few days ago and I immediately ordered the essential replacement part, a hot air popcorn popper, to avert a true crisis: no coffee! While I was rebuilding, I thought I’d take some pictures and share what I know about the subject. So if you’re interested in roasting coffee, making a popcorn popper into a roaster, or even just taking an inside look at a thoroughly value-engineered kitchen machine, read on!

Continue reading “Build An Excellent Coffee Roaster With A Satisfyingly Low Price Tag” →

Hackaday Belgrade Call For Proposals Now Open!

January 22, 2018 by Mike Szczys 6 Comments

Prepare yourself for the return of Hackaday Belgrade! Our premier European conference — Hackaday Belgrade — is on 26 May and we want to hear what you’ve been working on. The Call for Proposals is now open. We seek talks and workshops exploring the most interesting uses of technology and the culture that goes along with it. This includes design, prototyping, research, manufacturing, and the stories of people and progress that move hardware hacking forward.

We’ve booked Dom Omladine for the event because it was perfect for our previous Belgrade conference in 2016. The sold-out conference became a living organism of excitement when the Hackaday community from across Europe came together. A spectacular slate of speakers presented topics like designing computing clusters for use in University research programs, combining projection mapping with high powered lasers, building hardware for advertising campaigns, uncovering forgotten projector technology called Eidophor, fully embracing Open Hardware during product development, and so much more. All of this while hundreds in attendance joined forces for some of the best hardware badge hacking we’ve ever seen.

Hackaday Belgrade is the rare kind of opportunity that is worth reorganizing your life to attend. Want to guarantee yourself a ticket? They’re not available yet, but you can hack your way into the conference: submit a proposal! In addition to the adoration of the Hackaday community, accepted speakers will receive free admission. Everyone who submits a quality talk proposal will be given priority when tickets do go on sale. This event will sell out!

For updates, keep an eye on the conference page and pop into the chat on the project page by clicking “Join this project’s team”. Do you know someone who should be a speaker at this conference? Reach out to them personally, share this CFP on social media, or let us know in the comments below so we can make it happen.

Quantum Computing Hardware Teardown

January 22, 2018 by Bryan Cockfield 59 Comments

Although quantum computing is still in its infancy, enough progress is being made for it to look a little more promising than other “revolutionary” technologies, like fusion power or flying cars. IBM, Intel, and Google all either operate or are producing double-digit qubit computers right now, and there are plans for even larger quantum computers in the future. With this amount of inertia, our quantum computing revolution seems almost certain.

There’s still a lot of work to be done, though, before all of our encryption is rendered moot by these new devices. Since nothing is easy (or intuitive) at the quantum level, progress has been considerably slower than it was during the transistor revolution of the previous century. These computers work because of two phenomena: superposition and entanglement. A quantum bit, or qubit, works because unlike a transistor it can exist in multiple states at once, rather than just “zero” or “one”. These states are difficult to determine because in general a qubit is built using a single atom. Adding to the complexity, quantum computers must utilize quantum entanglement too, whereby a pair of particles are linked. This is the only way for any hardware to “observe” the state of the computer without affecting any qubits themselves. In fact, the observations often don’t yet have the highest accuracy themselves.

There are some other challenges with the hardware as well. All quantum computers that exist today must be cooled to a temperature very close to absolute zero in order to take advantage of superconductivity. Whether this is because of a reduction in thermal noise, as is the case with universal quantum computers based on ion traps or other technology, or because it is possible to take advantage of other interesting characteristics of superconductivity like the D-Wave computers do, all of them must be cooled to a critical temperature. A further challenge is that even at these low temperatures, the qubits still interact with each other and their read/write devices in unpredictable ways that get more unpredictable as the number of qubits scales up.

So, once the physics and the refrigeration are sorted out, let’s take a look at how a few of the quantum computing technologies actually manipulate these quantum curiosities to come up with working, programmable computers. Continue reading “Quantum Computing Hardware Teardown” →

Know Your Video Waveform

January 18, 2018 by Jenny List 84 Comments

When you acquired your first oscilloscope, what were the first waveforms you had a look at with it? The calibration output, and maybe your signal generator. Then if you are like me, you probably went hunting round your bench to find a more interesting waveform or two. In my case that led me to a TV tuner and IF strip, and my first glimpse of a video signal.

An analogue video signal may be something that is a little less ubiquitous in these days of LCD screens and HDMI connectors, but it remains a fascinating subject and one whose intricacies are still worthwhile knowing. Perhaps your desktop computer no longer drives a composite monitor, but a video signal is still a handy way to add a display to many low-powered microcontroller boards. When you see Arduinos and ESP8266s producing colour composite video on hardware never intended for the purpose you may begin to understand why an in-depth knowledge of a video waveform can be useful to have.

The purpose of a video signal is to both convey the picture information in the form of luminiance and chrominance (light & dark, and colour), and all the information required to keep the display in complete synchronisation with the source. It must do this with accurate and consistent timing, and because it is a technology with roots in the early 20th century all the information it contains must be retrievable with the consumer electronic components of that time.

We’ll now take a look at the waveform and in particular its timing in detail, and try to convey some of its ways. You will be aware that there are different TV systems such as PAL and NTSC which each have their own tightly-defined timings, however for most of this article we will be treating all systems as more-or-less identical because they work in a sufficiently similar manner.

Continue reading “Know Your Video Waveform” →