Harmonographs Generate Geometric Images Unique as Fingerprints

When my elder brother and I were kids back in the late 1970’s, our hacker Dad showed us this 1960-61 catalog of the Atlas Lighting Co (later Thorn Lighting) with an interesting graphic design on the cover. He told us to do a thought experiment, asking us to figure out how it would be possible to have a machine that would draw the design on that catalog cover.

Incorrectly, our first thought was that the design was created with a Spirograph. A spirograph has two main parts: a large ring with gear teeth on the inside and outside circumferences and a set of smaller, toothed wheels with holes in them for inserting a drawing instrument — usually a ball point pen. You hold the big ring, insert the pen in the smaller wheel, and then mesh and rotate the smaller wheel around the big ring. But spirographs can’t be used to draw irregular, asymmetrical figures. You could always recreate a design. Because of the nature of gears, none of them were unique, one off, designs.

A spirograph set like this cannot make the image above[Image credit: Multicherry CC-BY-SA 3.0]
A spirograph set like this cannot make the image above [Image credit: Multicherry CC-BY-SA 3.0]
We figured adding some lever arms, and additional geared wheels (compound gears) could achieve the desired result. It turns out that such a machine is called a Cycloid Drawing Machine. But even with this kind of machine, it was possible to replicate a design as often as required. You would fix the gears and levers and draw a design. If the settings are not disturbed, you can make another copy. Here’s a video of a motorized version of the cycloid machine.

The eventual answer for making such designs was to use a contraption called as the harmonograph. The harmonograph is unique in the sense that while you can make similar looking designs, it would be practically impossible to exactly replicate them — no two will be exactly the same. This thought experiment eventually led to my brother building his own harmonograph. This was way back when the only internet we had was the Library, which was all the way across town and not convenient to pop in on a whim and fancy. This limited our access to information about the device, but eventually, after a couple of months, the project was complete.

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Pancake-ROM: Eat-only Memory?

You can store arbitrary data encoded in binary as a pattern of zeros and ones. What you do to get those zeros and ones is up to you. If you’re in a particularly strange mood, you could even store them as strips of chocolate on Swedish pancakes.

Oddly enough, the possibility of the pancake as digital storage medium was what originally prompted [Michael Kohn] to undertake his similar 2013 project where he encoded his name on a paper wheel. Perhaps wisely, he prototyped on a simpler medium. With that perfected, four years later, it was time to step up to Modified Swedish Pancake Technology (MSPT).

pancake_rom_bottomHighlights of the build include trying to optimize the brightness difference between chocolate and pancake. Reducing the amount of sugar in the recipe helps increase contrast by reducing caramelization, naturally. And cotton balls placed under the spinning cardboard platform can help stabilize the spinning breakfast / storage product.

Even so, [Michael] reports that it took multiple tries to get the sixteen bytes (bites?) of success in the video below. The data is stenciled onto the pancake and to our eye is quite distinct. Improvement seems to be more of an issue with better edge detection for the reflectance sensor.

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Shape Programmable Matter is More Magnetic Magic

How could you build an artificial tadpole? Or simulate the motion of a cilium? Those would be hard to do with mechanical means — even micromechanical because of their fluid motion. Researchers have been studying shape-programmable matter: materials that can change shape based on something like heat or magnetic field. However, most research in this area has relied on human intuition and trial and error to get the programmed shape correct. They also are frequently not very fast to change shape.

[Metin Sitti] and researchers at several institutions have found a way to make rapidly changing silicone rubber parts (PDF link) that can change shape due to a magnetic field. The method is reproducible and doesn’t seem out of reach for a hackerspace or well-equipped garage lab.

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HackBusting: Can you Fake a TV Remote with a Lighter and some Paper?

We recently published an article where someone apparently controlled their TV by simulating a remote with merely a lighter and a sheet of paper. The paper had a barcode like cutout for a supposed “Universal Standby Signal”. The video rightfully attracted a substantial crowd, some awestruck by its simplicity, others sceptical about its claims.

Coming from some generic “Viral Life Hack” production house, the characteristic blare of background music, more suited to an underground rave than a technical video, certainly did not do it any favours. As any moderately experienced campaigner would know, modern televisions and remotes have been carefully engineered  to prevent such mishaps. Many of us at Hackaday, were under the impression that it would take something slightly more sophisticated than a fluorescent-bodied lighter and a crisp sheet of A4 to deceive the system. So we tested it out. Our verdict? Unlikely, but not impossible. (And we’re pretty sure that the video is a fake either way.) But enough speculation, we’re here to do science.

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The USB Killer: Now Faster, Better, More Anonymous

A few years ago, [Dark Purple] built the USB equivalent of an RJ45 connector wired into mains power. The USB Killer is a simple device with just a FET, a few high voltage caps, a DC/DC converter, and a USB connector. Plug this device into your computer and -220V is dumped directly into the USB signal wires. This kills your laptop dead.

Over the years we’ve seen the USB Killer evolve from a hand-etched PCB to something less discrete but more discreet. It was a crowdfunding campaign run by a company in Hong Kong, and a few months ago this new commercial version was released.

Now, the USB Killer V3 is out. It provides 1.5 times the power to your poor USB ports, with power surges twice as fast. There’s also an anonymous version that looks like every other USB thumb drive sourced from Hong Kong. This is your warning: never, ever plug an unknown USB thumb drive into your computer.

While a product announcement really isn’t news, it is extremely interesting to take a look at how something that should not exist is being marketed. As with all electronic destructive devices, it’s on your Amazon recommended products list alongside tactical kilts, fingerless gloves, beard oil, and black hoodies. This is pentesting gear, with an anonymous edition for your friend, the hacker called four chan. Don’t think too much about how you’re going to get data off a laptop you just killed, or how you would go undetected by destroying equipment; this is cool hacker stuff.

In addition, the USB Kill 2.0 is FCC and CE approved. This allows you to, “test in complete safety” (their emphasis, not ours).   We have no idea what this actually means.

Can a Bundle of Soda Straws be a Camera?

This one is hard to classify. Is it a hack, or is it art? Perhaps it’s both. However you want to classify it, it’s pretty cool to turn a bundle of drinking straws into a camera.

strawcamera_012
Click for larger image

If you’re looking for the technology here, you won’t find much. There’s no lens, no shutter, and no electronics of any kind in [Mick Farrell] and [Cliff Haynes]’ Straw Camera. This is literally a box full of drinking straws standing on end, with a sheet of photo paper behind it. Each straw sends a spot of light that represents the average hue and luminance of its limited view of the subject directly to the film. The process of making an exposure consists of composing the scene, turning out the lights, loading the camera, and setting off a flash.

The resulting images are defocused but recognizable, like seeing familiar sights through a heavy fog. The straws make a strong texture over the ghostly image of the subject – indeed, the straws are the only thing in focus. The fact that the straws don’t form a perfect honeycomb due to settling and imperfections in the bundles is jarring at first, but as you see the images you get used to the extra texture.

When we first saw this, we wondered about the possibility of putting a simple photosensor at the bottom of each straw to capture similar images digitally. The TCS3200 would be about the right size, but given that there are about 32,000 straws in the bundle, the BOM might get a little out of hand. Still, a scaled down digital straw camera might yield some interesting images.

Thanks to [Stuart Rogers] for the tip.

Video Series Shows Custom Machined Fly Reel

For those of us who can’t get enough vicarious machining, YouTube is becoming a gold mine. Intricate timepieces, gigantic pump shafts, and more and better machine tools are all projects that seem to pop up in our feed regularly.

With all that to choose from, can a series on building a fly fishing reel actually prove interesting? We think so, and if you enjoyed [Clickspring]’s recently completed pedestal clock, you might just get a kick out of what’s cooking in [JH Reels]’ shop. Comparing any machining videos to [Clickspring]’s probably isn’t very fair, but even with a high bar to hurdle, [JH Reels] comes out looking pretty good. The challenge here is that this is a saltwater fly reel, so extra care with material selection and machining methods ought to make for some interesting viewing. Also of interest is the range of tooling needed to produce the reel. From lathe to mill to waterjet cutter, a lot goes into these parts, and watching them come together is fascinating.

You wouldn’t think a seemingly simple mechanism like a fly reel would be so complicated to build. But there’s a lot more to it than meets the eye, and with a reel that’s clearly destined to be an heirloom piece, [JH Reels]’ attention to detail is impressive. The series currently stands at 10 videos, and we’re keen to see how it turns out.

The first video is posted below to whet your appetite. But if machining and fishing don’t do it for you, maybe you can try drones and fishing instead.

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