Front and back views of a square, purple PCB with op amps and BNC outputs

Op Amp Contest: Generate Spirograph Shapes Using Only Op Amps And Math

June 5, 2023 by Robin Kearey 13 Comments

If you’re a child of the ’80s or ’90s, chances are you’ve spent hours tracing out intricate patterns using the pens and gears of a Spirograph kit. Simple as those parts may be, they’re actually a very clever technique for plotting mathematical functions called hypotrochoids and epitrochoids. [Craig] has spent some time analyzing these functions, and realized you can also implement them with analog circuits. He used this knowledge to design a device called Op Art which generates Spirograph shapes on your oscilloscope using just a handful of op amps.

To draw either a hypotrochoid or an epitrochoid, you need to generate sine and cosine waves of various frequencies, and then add them with a certain scaling factor. Generating sines and cosines is not so hard to do with op amps, but making an adjustable oscillator that reliably churns out matching sine and cosine waves over a large frequency range turned out to be tricky. After a bit of experimentation, [Craig] discovered that a phase-shift oscillator was the right topology, not only for its adjustability but also because it generates sine, cosine and inverted sine terms that all come in handy when drawing various Spirograph shapes. Continue reading “Op Amp Contest: Generate Spirograph Shapes Using Only Op Amps And Math” →

The Most Ornate Birdbath You’ve Ever Seen

June 4, 2023 by Danie Conradie 8 Comments

When one thinks of art, a birdbath may not be the first thing that comes to mind. However, there is no denying that the La Fontaine aux Oiseaux (The Bird Fountain) is a true work of art. This automaton, created by automaton maker [François Junod] in collaboration with 20 different workshops and craftsmen, represents thousands of hours of work and boasts a complex beauty that is both visible and hidden.

Commissioned by the Van Cleef & Arpels jewelry company, this purely mechanical display piece features a pair of jewel-encrusted birds that perform a little routine around the edge of the bath every hour. All the birds’ appendages move while bird song is added with the help of a whistle and bellows. The “water” is also mechanized, with a series of metal plates moving together to create ripple effects, while a water lily opens and closes and a dragonfly flutters above the surface.

The overall effect of this ridiculously over-the-top mechanical art piece is absolutely mesmerizing. Even if the bejeweled exterior isn’t quite your style, you can still appreciate its intricate workings thanks the video after the break giving us a peek at the development.

We’ve featured some of [François]’ other work before, which is equally impressive and displays the mechanics in all it’s glory. If you want to try your hand at making automatons, 3D printing is the perfect way to get started.

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Supercon 2022: [Jorvon Moss] Gives His Robots A Soul

May 30, 2023 by Arya Voronova 6 Comments

How do you approach your robot designs? Maybe, you do it from a ‘oh, I have these cool parts’ position, or from a ‘I want to make a platform on wheels for my experiments’ perspective. In that case, consider that there’s a different side to robot building – one where you account for your robot’s influence on what other people around feel about them, and can get your creations the attention they deserve. [Jorvon ‘Odd-Jayy’ Moss]’s robots are catchy in a way that many robot designs aren’t, and they routinely go viral online. What are his secrets to success? A combination of an art background, a Bachelor of Fine Arts in illustration, and a trove of self-taught electronics skills helped him develop a standout approach to robot building.

Now, [Jorvon] has quite a few successful robot projects under his belt, and at Supercon 2022, he talks about how our robots’ looks and behaviour shapes their perception. How do your own robots look to others, and what feelings do they evoke? With [Jorvon], you will go through fundamentals of what makes a robot look lively, remarkable, catchy or creepy, and it’s his unique backgrounds that let him give you a few guidelines on what you should and should not do when building a certain kind of robot.

You’ll do good watching this video – it’s short and sweet, and shows you a different side to building robots of your dreams; plus, the robot riding around on the stage definitely makes this presentation one of a kind. No matter your robot’s technical complexity, it’s significant that it can make people go ‘wow’ when they see it. Not all robots are there to single-mindedly perform a simple task, after all – some are meant to travel around the world.

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Mat Boards Are Spendy, So DIY CNC Tool To The Rescue

May 29, 2023 by Donald Papp 22 Comments

Mats are flat pieces of paper-based material that fill the space between a frame and the art within. They perform a number of aesthetic and practical functions, and they can also be expensive to purchase. Making them by hand is an option, but it’s an exacting process. [wooddragon48] felt that a CNC solution would serve this need nicely, and began designing a DIY CNC tool to do exactly that.

One of the tricky parts about cutting mat boards is that cuts are at an angle, and there is really no tolerance for overcuts or any kind of visual blemish. CNC control would seem to offer a great solution to both the need for precisely straight cuts, as well as fine control over where cuts begin and end in a way that opens the door to complex designs that would be impractical to do by hand.

[wooddragon48]’s design has an angled cutter designed to plunge perfectly on demand, surrounded by a ring — similar to that on a router — which ensures the cutting tool is always consistently positioned with the material. It’s still in the design phase, but this is a type of tool that doesn’t yet exist so far as we can tell. The ability to CNC cut mat board, especially in complex designs, would be a huge timesaver.

Art and DIY CNC have a long history of happy intersection, as we have seen with a CNC router repurposed for string art, a CNC painting robot, and even an interactive abstract sculpture generator.

AI Image Generation Gets A Drag Interface

May 27, 2023 by Donald Papp 15 Comments

AI image generators have gained new tools and techniques for not just creating pictures, but modifying them in consistent and sensible ways, and it seems that every week brings a fascinating new development in this area. One of the latest is Drag Your GAN, presented at SIGGRAPH 2023, and it’s pretty wild.

It provides a point-dragging interface that modifies images based on their implied structure. A picture is worth a thousand words, so this short animation shows what that means. There are plenty more where that came from at the project’s site, so take a few minutes to check it out.

GAN stands for generative adversarial network, a class of machine learning that features prominently in software like image generation; the “adversarial” part comes from the concept of networks pulling results between different goalposts. Drag Your GAN has a GitHub repository where code is expected to be released in June, but in the meantime, you can read the full paper or brush up on the basics of how AI image generators work, as well as see how image generation can be significantly enhanced with an understanding of a 2D image’s implied depth.

An orange and green stained glass robot arm sits on a table with a yellow lace tablecloth. It suspends a teabag over a brown teacup. You can see green leaves outside the window behind the bot.

Glass Robot From A Solarpunk Future

May 24, 2023 by Navarre Bartz 5 Comments

You may have heard of a heart of glass or have a glass jaw, but have you ever seen a glass robot?

[Simone Giertz], has taken two of her favorite things, stained glass and robotics, and fused them into a single project. Using an existing metal robot arm as a template, she cut and soldered her stained glass panels before reassembling the robot with its new solarpunk limbs. During testing though, one of the glass panels repeatedly failed at a solder joint.

Undaunted, [Giertz] replaced the faulty piece with an original metal component allowing this “grandma cyberpunk-core” bot to prepare tea as intended. We really love when makers bring us through the whole process, mishaps and all, and [Giertz] never disappoints in this respect. We do wonder a bit about the long-term health impacts of making tea with a robot containing leaded solder though.

If you’re interested in more robots made from unusual materials, checkout this gripper made from a dead spider or this work on phase changing robots.

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Early Computer Art From The 1950s And 1960s

May 19, 2023 by Joseph Long 5 Comments

Modern day computer artist, [Amy Goodchild] surveys a history of Early Computer Art from the 1950s and 1960s. With so much attention presently focused on AI-generated artwork, we should remember that computers have been used to created art for many decades.

Our story begins in 1950 when Ben Laposky started using long exposure photography of cathode ray oscilloscopes to record moving signals generated by electronic circuits. In 1953, Gordon Pask developed the electromechanical MusiColor system. MusiColor empowered musicians to control visual elements including lights, patterns, and motorized color wheels using sound from their instruments. The musicians could interact with the system in real-time, audio-visual jam sessions.

In the early 1960s, BEFLIX (derived form Bell Flix) was developed by Ken Knowlton at Bell Labs as a programming language for generating video animations. The Graphic 1 computer featuring a light pen input device was also developed at Bell Labs. Around the same timeframe, IBM introduced novel visualization technology in the IBM 2250 graphics display for its System/360 computer. The 1967 IBM promotional film Frontiers in Computer Graphics demonstrates the capabilities of the system.

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