a kinetic bar framework mounted on a wooden base made of 3d printed bars of alternative black and grey color, each joined with m3 bolts and nuts

Kinetic Cyclic Scissors

October 26, 2022 by Abe Connelly 6 Comments

[Henry Segerman] and [Kyle VanDeventer] merge math and mechanics to create a kinetic cyclic scissors sculpture out of 3D printed bars adjoined together with M3 bolts and nuts.

The kinetic sculpture can be thought of as a part of an infinite tiling of self similar quadrilaterals in the plane. The tiling of the plane by these self similar quadrilaterals can be realized as a framework by joining the diagonal points of each quadrilateral with bars. The basic question [Henry] and [Kyle] wanted to answer was under what conditions can the realized bar framework of a subsection of the tiling be made to move. Surprisingly, when the quadrilateral is a parallelogram, like in a scissor lift, or “cyclic”, when the endpoints lie on a circle, the bar framework can move. Tweaking the ratios of the middle lengths in a cyclic configuration leads to different types of rotational symmetry that can be achieved as the structure folds in on itself.

[Henry] and [Kyle] go into more detail in their Bridges Conference paper, with derivations and further discussions about the symmetry induced by adjusting the constraints. The details are light on the actual kinetic sculpture featured in the video but the bar framework was chosen to have a mirror type of symmetry with a motor attached to one of the central, lower bars to drive the movement of the sculpture.

The bar framework is available for download for anyone wanting to 3D print or laser cut their own. Bar frameworks are useful ideas and we’ve seen them used in art sculptures to strandbeests, so it’s great to see further explorations in this space.

Video after the break!

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A diagram showing an LED on the left, a lever-style plumbing valve in the center, and an Arduino Uno on the right.

Plumbing Valves As Heavy Duty Analog Inputs

October 24, 2022 by Navarre Bartz 36 Comments

Input devices that can handle rough and tumble environments aren’t nearly as varied as their more fragile siblings. [Alastair Aitchison] has devised a brilliant way of detecting inputs from plumbing valves that opens up another option. (YouTube) [via Arduino Blog]

While [Aitchison] could’ve run the plumbing valves with water inside and detected flow, he decided the more elegant solution would be to use photosensors and an LED to simplify the system. This avoids the added cost of a pump and flow sensors as well as the questionable proposition of mixing electronics and water. By analyzing the change in light intensity as the valve closes or opens, you can take input for a range of values or set a threshold for an on/off condition.

[Aitchison] designed these for an escape room, but we can see them being great for museums, amusement parks, or even for (train) simulators. He says one of the main reasons he picked plumbing valves was for their aesthetics. Industrial switches and arcade buttons have their place, but certainly aren’t the best fit in some situations, especially if you’re going for a period feel. Plus, since the sensor itself doesn’t have any moving parts, these analog inputs will be easy to repair should anything happen to the valve itself.

If you’re looking for more unusual inputs, check out the winners of our Odd Inputs and Peculiar Peripherals contest or this typewriter that runs Linux.

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How The Image-Generating AI Of Stable Diffusion Works

October 24, 2022 by Donald Papp 40 Comments

[Jay Alammar] has put up an illustrated guide to how Stable Diffusion works, and the principles in it are perfectly applicable to understanding how similar systems like OpenAI’s Dall-E or Google’s Imagen work under the hood as well. These systems are probably best known for their amazing ability to turn text prompts (e.g. “paradise cosmic beach”) into a matching image. Sometimes. Well, usually, anyway.

‘System’ is an apt term, because Stable Diffusion (and similar systems) are actually made up of many separate components working together to make the magic happen. [Jay]’s illustrated guide really shines here, because it starts at a very high level with only three components (each with their own neural network) and drills down as needed to explain what’s going on at a deeper level, and how it fits into the whole.

Spot any similar shapes and contours between the image and the noise that preceded it? That’s because the image is a result of removing noise from a random visual mess, not building it up from scratch like a human artist would do.

It may surprise some to discover that the image creation part doesn’t work the way a human does. That is to say, it doesn’t begin with a blank canvas and build an image bit by bit from the ground up. It begins with a seed: a bunch of random noise. Noise gets subtracted in a series of steps that leave the result looking less like noise and more like an aesthetically pleasing and (ideally) coherent image. Combine that with the ability to guide noise removal in a way that favors conforming to a text prompt, and one has the bones of a text-to-image generator. There’s a lot more to it of course, and [Jay] goes into considerable detail for those who are interested.

If you’re unfamiliar with Stable Diffusion or art-creating AI in general, it’s one of those fields that is changing so fast that it sometimes feels impossible to keep up. Luckily, our own Matthew Carlson explains all about what it is, and why it matters.

Stable Diffusion can be run locally. There is a fantastic open-source web UI, so there’s no better time to get up to speed and start experimenting!

Watermelon CNC Uses Lazy Susan

October 12, 2022 by Al Williams 27 Comments

It is the time of year when a lot of people in certain parts of the world carve pumpkins. [Gonkee] is carving a watermelon, which we assume is similar. He decided to make a CNC machine to do the carving for him. The unusual part is the use of two lazy Susans to make a rotary carving machine. You can see the result in the video below.

The hardware is clever and there is software that lets you do drawings, although we were hoping for something that would process gcode or slice STL. That would be a worthy add-on project. There were a few iterations required before the Melon Carver 3000 worked satisfactorily. Seeing a carving tool operating on two circles gives us a lot of ideas. We aren’t sure how sturdy the mounts are, so don’t plan on carving aluminum without some changes, but we suspect it is possible.

Then again, a laser head mounted on the frame would have probably made short work of the melon, and wouldn’t require much mechanical stiffness. It would, however, take a little effort to keep it in focus. So many ideas to try!

Watermelon is a popular hacking medium, apparently. There’s even one that holds a GameBoy.

front and back of the Jolly Wrencher SAO

Jolly Wrencher SAO, And How KiCad 6 Made It Easy

October 11, 2022 by Arya Voronova 17 Comments

If you plan to attend Supercon or some other hacker conference, know that you’re going to get a badge with a SAO (Simple Add-On) connector, a 4-pin or 6-pin connector that you can plug an addon board onto. There’s myriads of SAOs to choose from, and if you ever felt like your choice paralysis wasn’t intense enough, now you have the option of getting a Jolly Wrencher SAO board!

This board gives you an SMD prototyping space, with 1.27mm (0.05″ pitch) pads, suitable for many passive components, ICs and even modules like the ESP32 WROOM. Those pads are diagonally interspersed with ground-fill-connected pads – if you want to bodge something on the spot, you don’t need to pull separate GND wires. Given the Supercon badge specifics, the SAO-standard SDA and SCL pins have RX and TX labels as well. For bonus points, the eyes are transparent, with LED footprints behind them – it’s my first time designing a PCB where the LED shines through the FR4, and I hope that the aesthetics work out!

This design is open with gerber files available for download, so if you thought of making a quick PCB order, I’m giving you one more .zip file to add to it. Otherwise, it’s possible that you will find a Wrencher board lying around at Supercon! Now, I’d like to tell you how KiCad 6 made it super easy to design this PCB – after all, there’s never enough SAOs, and it’s quite likely you’ll want to design your own special SAO, too.

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A tiny CRT showing an eye, inside a plexiglass enclosure

This Eye Is Watching You From Its Tiny CRT

October 9, 2022 by Robin Kearey 25 Comments

The days of cathode ray tubes, or CRTs, are firmly behind us, and that’s generally a good thing. Display tubes were heavy, bulky and fragile, and needed complicated high-voltage electronics in order to work. But not all of them were actually large: miniature display tubes were also produced, for things like camcorder viewfinders, and [Tavis] from Sideburn Studios decided to turn one of those into a slightly creepy art project.

The heart of this build is a one-inch CRT that was salvaged from an RCA video camera. [Tavis] mounted the tiny tube inside an acrylic box on a 3D printed base. Inside that base sits a Raspberry Pi along with a high-voltage driver and a power management board. The Pi continuously plays a video that shows a human eye blinking and looking in various directions. Just an eye, floating in space, looking at the world around it.

The magic is briefly lost when the Pi starts up, because it then shows a microscopic version of the Pi’s standard bootup sequence, but once the thing is running it adds a weird vibe to a room. It actually looks like something you’d find in an avant-garde art exhibition — in the video (embedded below) it’s accompanied by eerie music that gives it an even more unsettling feel. Electronic eyes are always a bit scary, especially when they’re actually looking at you.

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Flux: A Forty Foot Long Kinetic Art Piece

October 7, 2022 by Dave Rowntree 5 Comments

No office space is complete without some eye-catching art piece to gawp at whilst you mull over your latest problem. But LED-based displays are common enough to be boring these days. Kinetic art pieces are where it’s at, and this piece called Flux is a perfect example.

Commissioned for the Toronto office of a very popular e-commerce platform and constructed by [Nicholas Stedman], Flux consists of twenty identical planks on the ceiling, arranged in a line forty feet long. Each plank has a pair of rotating prisms, constructed from a stack of foam sheets, finished with metallic paint. The prisms are spun by individual stepper motors, each of which is driven by a TMC2160-based module, making them whisper-quiet.

A simple 3D printed bracket holds a small PCB holding an AMS AS5600 rotary magnetic encoder, onto the rear of the stepper motor. This allows for closed-loop feedback to the shared Arduino, which is very important for a sculpture such as this. Each Arduino is hooked up to a Raspberry Pi, running a simple application written in node.js which is responsible for coordinating movement, as well as uploading updated firmware images as required. A simple, but very effective build, we think!

Even more fun are kinetic art installations that are reactive to some data source, such as Adad, which visualizes lightning strike data. If these builds are just too big and complex, we’ve seen many examples of smaller desktop toys, such as this 3D printed tumbling chain demo for example.

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