Photochromic Eggs: Not for Breakfast

Photochromic paint is pretty nifty – under exposure to light of the right wavelength, it’ll change colour. This gives it all kinds of applications for temporary displays.  [Jiri Zemanek] decided to apply photochromic paint to an egg, utilising it to create stroboscopic patterns with the help of a laser.

Patterns for the egg are generated in MATLAB. A Discovery STM32 board acts as a controller, looking after the laser scanner and a stepper motor which rotates the egg. A phototransistor is used to sync the position of the laser and the egg as it rotates.

The photochromic paint used in this project is activated by UV light. To energize the paint, [Jiri] harvested a violet laser from a Blu-ray player, fitting it to a scanning assembly from a laser printer. Instead of scanning the laser across an imaging drum, it is instead scanned vertically on a rotating egg. Patterns can then be drawn on the egg, which fade over time as the paint gives up its stored energy.

[Jiri] exploits this by writing a variety of patterns onto the egg, which then animate in a manner similar to a zoetrope – when visualised under strobing light, the patterns appear to move. There are also a few holiday messages shown for Easter, making the egg all the more appropriate as a billboard.

If you like the idea of drawing on eggs but are put off by their non-uniform geometry, check out the Egg-bot. Video below the break.

Continue reading “Photochromic Eggs: Not for Breakfast”

The Haunting Last Day of Hot Metal Typesetting at The New York Times

The short film, Farewell — ETAOIN SHRDLU, produced in 1978 covers the very last day the New York Times was set for printing in the old way, using hot metal typesetting.

We’ve covered the magic of linotype machines before, but to see them used as they were in their prime is something else. They saw nearly a hundred years of complete industry dominance. Linotype machines had entire guilds dedicated to their use. Tradesmen built their lives around them. For some of us we see the rise and fall of technology as an expected thing. Something that happens normally, sometimes within spans that cover only a few short years. Yet it’s still a strange thing to see a technology so widely used shut down so completely and relatively rapidly.

To make it even stranger, the computer that replaced the linotype machines is so alien to the technology used today that even it is an oddity. In the end only the shadow of the ‘new’ technologies — showcased as state of the art in this video — are still in use. Nonetheless it’s important to see where we came from and to understand what it means to innovate. Plus, you never know when you see an old idea that’s ready for a bit of refurbishment. Who knows, maybe part of the linotype’s spirit is ready to be reborn, and all it takes is a clever hacker to see it.

Oh, and that title — ‘etaoin shrdlu‘ — is the linotype equivalent of ‘qwerty’. The first two columns of keys on the linotype machine make up those two words.

Continue reading “The Haunting Last Day of Hot Metal Typesetting at The New York Times”

Rubicon gives the Makerbot Digitizer a run for its money


Look out MakerBot, there’s a new 3D scanner on the block and it’s about 10% of the cost of the Digitizer. Enter the Rubicon 3D Scanner which just hit Indiegogo, a device much closer to being worth its price $199.

Just like the pricey Makerbot Digitizer it’s a very simple design made up of a webcam, two laser lines, and a stepper motor controlled turn table. Still very easy to make yourself, but at $199, it’s not a bad price for an all-in-one kit, especially compared to the Digitizer. The newcomer claims a much faster scan time (3 minutes versus 12), and the same stepper rotation (800 steps or 0.45 degrees per step). There are no details about making the design open source, but after some digging in the RepRap forums we found some discussion on that topic from designer [Robert].

It scans objects up to 160mm in diameter and 250mm tall, however it has the ability to scan marginally larger objects if the camera is moved farther back. The funding for the Indiegogo campaign will go towards a custom arduino-esq PCB with a motor driver built in – personally we would be interested in just getting the PCB and 3D printing the rest of the scanner ourselves!

More information is found in the video after the break. Continue reading “Rubicon gives the Makerbot Digitizer a run for its money”

Cheap DIY laser scanner is quite impressive

With the introduction of the Kinect, obtaining a 3D representation of a room or object became a much easier task than it had been in the past. If you lack the necessary cash for one however, you have to get creative. Both the techniques and technologies behind 3D scanning are somewhat complicated, though certainly still within reach as maker [Shikai Chen] shows us. (Google Translation)

He wanted to create 3D scanned images, but he didn’t have the resources to purchase a Kinect. Instead, he built his own scanner for about 1/6th the cost. Interestingly enough, the scanner resembles what you might imagine a very early Kinect prototype looked like, though it functions just a little bit differently than Microsoft’s creation. The scanner lacks any sort of IR emitter/camera combo, opting to use a laser and a USB VGA camera instead. While scanning, the laser shines across the target surface, and the reflected light is then picked up by the camera.

So how does this $25 DIY laser scanner measure up? Great, to be honest. Check out the video below to see how well his scanner works, and be sure to take a look through his second writeup (Google Translation) as well for more details on the project.

[via Seeedstudio]

Convert a DVD-R Drive into a Lab scanner

[bodiby] was first to send in this New Scientist article about converting a DVD drive into a lab scanner. I did some digging and came up with the details. Here’s the paper describing the process and results. Here’s a basic schematic and description of the mod. A set of samples is placed onto a CDR. A photo sensor is used to locate the samples on the CD, while the laser is fired through each sample. A planar photodiode is used to measure the attenuation of the laser as it’s transmitted through each sample. Sadly, I couldn’t find any details on the custom control electronics.