Robotic Ball-Bouncing Platform Learns New Tricks

June 30, 2021 by Donald Papp 11 Comments

[T-Kuhn]’s Octo-Bouncer platform has learned some new tricks since we saw it last. If you haven’t seen it before, this device uses computer vision from a camera mounted underneath its thick, clear acrylic platform to track a ball in 3D space, and make the necessary (and minute) adjustments needed to control the ball’s movements with a robotic platform in real time.

We loved the Octo-Bouncer’s mesmerizing action when we saw it last, and it’s only gotten better. Not only is there a whole new custom ball detection algorithm that [T-Kuhn] explains in detail, there are also now visualizations of both the ball’s position as well as the plate movements. There’s still one small mystery, however. Every now and again, [T-Kuhn] says that the ball will bounce in an unexpected direction. It doesn’t seem to be a bug related to the platform itself, but [T-Kuhn] has a suspicion. Since contact between the ball and platform is where all the control comes from, and the ball and platform touch only very little during a bounce, it’s possible that bits of dust (or perhaps even tiny imperfections on the ball’s surface itself) might be to blame. Regardless, it doesn’t detract from the device’s mesmerizing performance.

Design files and source code are available on the project’s GitHub repository for those who’d like a closer look. It’s pretty trippy watching the demonstration video because there is so much going on at once; you can check it out just below the page break.

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The Incredible Mechanical Artistry Of François Junod

June 29, 2021 by Danie Conradie 16 Comments

The art of building purely mechanical automatons has dramatically declined with the arrival of electronics over the past century, but there are still a few craftsmen who keep the art form alive. [François Junod] is one of these masters, and the craftsmanship and intricacy on display in his automata is absolutely amazing.

[François]’ creations are all completely devoid of electronics, and are powered either by wound-up springs or weights. The mechanics of the automata are part of the display, and contain a vast array of gears, linkages, belts and tracks. Many of them also include their own soundtrack, which range from simple bells and chimes to complete melodies from mechanized wind instruments, as demonstrated in Le Champignonneur below. He also collaborates with craftsman like jewelers on works like La Fée Ondine, which we thought was CGI when we first saw it in the video after the break.

Very few people have the time, skill and patience to make these creations, but we are glad there are still a few around. Some builds, like [Patelo]’s flightless drone aren’t quite as complex, but are no less inspiring. If you don’t quite have the time and fabrication skills, you can still create mesmerizing automatons with 3D printing like [gzumwalt]. Continue reading “The Incredible Mechanical Artistry Of François Junod” →

Iridescent Rainbow Chocolate, Just Add Diffraction Grating!

May 23, 2021 by Donald Papp 15 Comments

Chocolate plus diffraction grating equals rainbow chocolate

Here’s a great picture from [Jelly & Marshmallows] that shows off the wild effects of melted chocolate poured onto a diffraction grating. A diffraction grating is a kind of optical component whose micro-features act to disperse and scatter light. Diffraction gratings are available as thin plastic film with one side that is chock full of microscopic ridges, and the way light interacts with these ridges results in an iridescent, rainbow effect not unlike that seen on a CD or laserdisc.

It turns out that these micro-ridges can act as a mold, and pouring chocolate over a diffraction grating yields holo-chocolate. These photos from [Jelly & Marshmallows] show this effect off very nicely, but as cool as it is, we do notice that some of the letters seem a wee bit hit-or-miss in how well they picked up the diffraction grating pattern.

Fortunately, we know just what to suggest to take things to the next level. If you want to know more about how exactly this effect can be reliably accomplished, you’ll want to check out our earlier coverage of such delicious optics, which goes into all the nitty-gritty detail one could ever want about getting the best results with either melted sugar, or dark chocolate.

Artwork Spans Fifty Years Of Display Technology

May 9, 2021 by Chris Lott 20 Comments

Swiss artist and designer [Jürg Lehni] was commissioned to create an artwork called Four Transitions which has been installed in the HeK (House of electronics Arts) in Basel. This piece visually depicts the changes in technologies used by public information displays, such as those in airports and train stations. As the title of the installation suggests, four different technologies are represented:

Flip-Dot, early 1960s, 15 each 7 x 7 modules arrayed into a 21 x 35 pixel panel
LCD, 1970s and 1980s, two each 36 x 52 modules arrayed into 52 x 76 pixel panel
LED, 2000s, six each 16 x 16 RGB modules arrayed into a 32 x 48 pixel panel
TFT, current, one 24 inch module, 1200 x 1920 pixel panel

The final work is quite striking, but equally interesting is the summary of the the design and construction process that [Jürg] provides on Twitter. We hope he expands this into a future, more detailed writeup — if only to learn about reverse engineering the 20 year old LCD controller whose designer was in retirement. His tweets also gives us a tantalizing glimpse into the software, controllers, and interconnections used to drive all these displays. There is quite a lot of interesting engineering going on in the background, and we look forward to future documentation from [Jürg].

You may recognize [Jürg] as the creator of Hektor, a graffiti output device from 2002 which we’ve referenced over the years in Hackaday. Check out the short video below of the displays in operation, and be sure to unmute the volume so you can listen to the satisfying sound of 735 flip-dots changing state. [Jürg] also gives in interview about the project in the second video below. Thanks to [Niklas Roy] for sending in the tip about this most interesting exhibition.

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Improved Graphics-to-Drawing Tablet Conversion

May 7, 2021 by Chris Lott 7 Comments

[Akaki Kuumeri] had an old Wacom Intuos digitizing graphics tablet collecting dust, and figured out how to non-destructively transform it into a drawing tablet. He was inspired by an old Hackaday post of a similar hack, but it required literally hacking a big hole into your Wacom tablet. Not wanting to permanently ruin the Wacom tablet, [Akaki] instead designed a 3D printed frame which he holds in place with a pair of straps. The design files are available on Thingiverse. He names the project, incorrectly as he later points out, WacomOLED (it rhymes with guacamole, we think).

As for the screen, he buys an old third-generation iPad and removes its Retina display panel and the foil backing, which would otherwise block the stylus’s connection to the tablet. Toss in an HDMI driver board to connect the display to your computer, and presto — you have made your own a drawing tablet. Even if you don’t need a drawing tablet, [Akaki]’s hack is still interesting, if only to remind us that we can put custom HDMI displays into any project for $65 using this technique.

In the end, [Akaki] notes that unless you already have a non-graphical digitizing tablet laying around, it’s probably cheaper to just buy a iPad. This is not [Akaki]’s first go at user input devices — we wrote about his Smash Brothers game controller and flight controller yoke project last year.

Do any of you use a graphics tablet in your day to day workflow? Let us know in the comments below.

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Julius Sumner Miller Made Physics Fun For Everyone

May 5, 2021 by Kristina Panos 38 Comments

Let’s face it — for the average person, math and formulas are not the most attractive side of physics. The fun is in the hands-on learning, the lab work, the live action demonstrations of Mother Nature’s power and prowess. And while it’s true that the student must be willing to learn, having a good teacher helps immensely.

Professor Julius Sumner Miller was energetic and enthusiastic about physics to the point of contagiousness. In pictures, his stern face commands respect. But in action, he becomes lovable. His demonstrations are dramatic, delightful, and about as far away from boring old math as possible. Imagine if Cosmo Kramer were a physics professor, or if that doesn’t give you an idea, just picture Doc Brown from Back to the Future (1985) with a thick New England accent and slightly darker eyebrows. Professor Miller’s was a shouting, leaping, arm-waving, whole-bodied approach to physics demonstrations. He was completely fascinated by physics, and deeply desired to understand it as best he could so that he could share the magic with people of all ages.

Professor Miller reached thousands of students in the course of his nearly 40-year teaching career, and inspired millions more throughout North America and Australia via television programs like The Mickey Mouse Club and Miller’s own show entitled Why Is It So? His love for science is indeed infectious, as you can see in this segment about the shock value of capacitors.

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Faux Stained Glass Effect, With 3D Printing And Epoxy

April 22, 2021 by Donald Papp 14 Comments

Like the looks of stained glass, but not the amount of work, skill, and materials involved? Well, [Northern Geometry] shows how to sidestep all that nonsense and use a 3D printed frame, epoxy, and some alcohol-based inks to create a pretty good fake stained-glass effect piece of art.

A smooth polypropylene board is the key to a glassy smooth back.

[Northern Geometry] has played with this idea before, but shares some refinements and tips on getting the best results. One suggestion is to begin by securely taping the 3D printed frame to a smooth polypropylene board as a backer. Giving the cured resin a smooth surface is important to get the right look, and since resin will not bond to the polypropylene, it can be used as a backer to get that done.

Once the frame is mounted, pour a small amount of epoxy into each cavity and ensure it gets into every corner, then let it cure. The thin bottom layer of resin will seal things as well as create a glassy-smooth backing that is the perfect foundation for finishing the piece with colored resin as needed.

Once that is done, and everything has had plenty of time to cure fully, just pop the piece off the board. Check it out in the video embedded below, where [Northern Geometry] shows the process from start to finish.

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