Arduino Drives Faux Spirograph

December 10, 2021 by Al Williams 11 Comments

The holidays always remind us of our favorite toys from when we were kids. Johnny Astro, an Erector set, and — of course — a Spirograph. [CraftDiaries] has an Arduino machine that isn’t quite a Spirograph, but it sure reminds us of one. The Arduino drives two stepper motors that connect to a pen that can create some interesting patterns.

The build uses a few parts that were laser cut, but they don’t look like they’d be hard to fabricate using conventional means or even 3D printing. The author even mentions you could make them out of cardboard or foamboard if you wanted to.

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Build Your Own Submarine

December 10, 2021 by Al Williams 22 Comments

If you are tried of building things that fly, why not try a submarine like [DIYPerks] did? As you can see in the video below, the key is to control buoyancy, and the mechanism used is impressive. The sub has two giant syringes fore and aft to compress or decompress water. The plungers are now 3D-printed actuators that travel on a lead screw. Two high-torque motors and some batteries sandwiched in acrylic disks make up the rest. This is a big vessel — you won’t be trying this in your bathtub and maybe not even your pool unless it is a big one.

Of course, everything needs to be watertight. Instead of trying to waterproof a power switch, this sub uses a reed switch so that a nearby magnet can turn it on. Not an original idea, but we always think it is more elegant than seals and potting compounds.

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Classic Colorimeter Clone Calibrates Cuvettes’ Contents

December 6, 2021 by Robin Kearey 13 Comments

For anyone dabbling in home chemistry, having access to accurate measurement equipment can mean the difference between success and failure. But with many instruments expensive and hard to find, what’s a home chemist to do? Build their own equipment, naturally. [Abizar] went ahead and built himself a colorimeter out of wood and spare electronic components.

A colorimeter (in a chemistry context) is an instrument that determines the concentration of a solution by measuring how much light of a certain wavelength is absorbed. [Abizar]’s design was inspired by the classic Klett-Summerson colorimeter from the 1950s, which uses a light bulb and color filters to select a wavelength, plus a photoresistor to measure the amount of light absorbed by the sample. Of course, a more modern solution would be to use LEDs of various colors, which is exactly what [Abizar] did, although he did give it a retro touch by using an analog meter as the readout device.

The body of the colorimeter is made from laser-cut pieces of wood, which form a rigid enclosure when stacked together. The color wheel holds eleven different LEDs and is made with a clever ratchet mechanism to keep it aligned to the cuvette, as well as a sliding contact to drive current into the selected LED. All parts are painted black to prevent stray reflections inside the instrument, but also make it look cool enough to fit in any evil genius’s lab. In the video embedded below, [Abizar] demonstrates the instrument and shows how it was put together.

While we haven’t seen anyone make their own colorimeter before, we have seen DIY spectrophotometers (which measure the entire absorption spectrum of a solution) and even building blocks to make a complete biochemistry lab.

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Low Buck PVC ROV IS Definitely A MVP

December 2, 2021 by Ryan Flowers 8 Comments

Do you have a hundred bucks and some time to kill? [Peter Sripol] invites you to come along with him and build a remotely operated submarine with only the most basic, easily accessible parts, as you can see in the video below the break.

Using nothing more than PVC pipe, an Ethernet cable, and a very basic electrical system, [Peter] has built a real MVP of a submarine. No, not Most Valuable Player; Minimum Viable Product. You see, there’s not a microcontroller, motor controller, sensor, or MOSFET to be found except for that which might reside inside the knock-off GoPro style camera which is encased in a candle wax sealed enclosure.

Instead, simple brushed motors live right out in the open water. Single pole double throw switches are connected to 100 feet of Ethernet cable and control the relays powering the motors. The camera signal is brought back to the controller through the same cable. Simple is the key to the build, and we have to admit that for all of its Minimum Viability, the little ROV has a lot going for it. [Peter] even manages to use the little craft to find and make possible the retrieval of a crustacean encrusted shopping cart from a saltwater canal. Not bad, little rover, not bad.

Also noteworthy is that the video below has its own PVC ROV Sea Shanty, which is something you just don’t hear every day.

Underwater ROV builds are the sort of thing almost every hacker thinks about doing at least once, and some hackers even include Lego, magnets, and balloons in their builds! Continue reading “Low Buck PVC ROV IS Definitely A MVP” →

FlowIO Takes Top Honors In The 2021 Hackaday Prize

November 20, 2021 by Dan Maloney 8 Comments

FlowIO Platform, a modular pneumatics controller for soft robotics and smart material projects, took home Grand Prize honors at the 2021 Hackaday Prize. Aside from the prestige of coming out on top of hundreds of projects and bragging rights for winning the biggest hardware design challenge on Earth, the prize carries an award of $25,000 and a Supplyframe DesignLab residency to continue project development. Four other top winners were also announced at the Hackaday Remoticon virtual conference on Saturday evening.

In a year full of challenges, this year’s Hackaday Prize laid down yet another gauntlet: to “Rethink, Refresh, and Rebuild.” We asked everyone to take a good hard look at the systems and processes that make the world work — or in some cases, not work — and reimagine them from a fresh perspective. Are there better ways to do things? What would you come up with if you started from a blank piece of paper? How can you support and engage the next generation of engineers, and inspire them to take up the torch? And what would you come up with if you just let your imagination run wild?

And boy, did you deliver! With almost 500 entries, this year’s judges had quite a task in front of them. Each of the five challenges — Refresh Displays, Rethink Work-From-Home Life, Reimagine Supportive Tech, Redefine Robots, and Reactivate Wildcard — had ten finalists, which formed the pool of entries for the overall prize. And here’s what they came up with.

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A 3D-printed maypole braider can produce woven tubes of rope, yarn, or whatever you've got. Al dente spaghetti strands, maybe.

3D-Printed Braiding Machine Will Show You The Ropes

November 4, 2021 by Kristina Panos 5 Comments

A maypole braider, aka a circular braider, is a type of horn gear braider that makes braided tubes, like one of those woven finger traps or that lovely bit of gutted paracord that’s jazzing up your otherwise boring DIY USB cable. They are called so because the action mimics the motion of a group of maypole dancers bobbing and weaving around each other in an intricate choreography that results in an equally intricate pole decoration job.

Maypole braiders like [kmatch98]’s are responsible for all kinds of ropes, cords, and other braided goods like fly-fishing lines. They use three or more bobbins, each loaded up with a single strand of yarn.

One of the most important parts of braiding anything, including hair, is maintaining tension on the braid as you go. Here, each bobbin rides inside a bobbin carrier, which performs a number of tasks — it holds the bobbin in place, releases yarn when it’s supposed to, and maintains tension on the yarn while skating a figure eight around the track.

This mesmerizing machine consists of spur gears, a frame with a figure 8 track, a pair of horn gears, and a foot — a guide on the bottom of the bobbin that rides along in the track. Early on, [kmatch98] made a fidget spinner version to visualize the basic function. He studied pictures of commercial bobbin carriers and managed to not only reverse engineer them, but improve the design by eliminating one of the two springs and replacing it with gravity. The remaining spring is used for the bobbin release.

Surprisingly, this isn’t the first plastic braiding machine we’ve featured. Here’s one made of freakin’ LEGO.

Really Robotic Robot Costume Will Probably Win The Contest

October 28, 2021 by Kristina Panos 8 Comments

Still don’t have anything to wear to that Halloween party this weekend? Or worse, your kid hasn’t decided on a costume that you both can agree on? Well, look no further than [Natasha Dzurny]’s Sally Servo the Really Robotic Robot Costume and accompanying multi-part build guide. You might want to start by raiding that recycle bin for cardboard, because you’re going to need a lot of it.

What you won’t need a lot of is hard-to-source parts, at least if you build it the [Natasha] and Brown Dog Gadgets way. Even so, there are a ton of cool moving and blinking bits and bobs to be made with servos, LEDs, and RGB LEDs connected up to something kid-friendly like the Micro:bit and the Brown Dog Gadgets Bit Board — that’s a base for the :bit that lets users connect components via LEGO and conductive tape.

Between Sally’s robotic googly eyes and her light-up belt, there are plenty of ideas here to steal and make your own, and each one is packaged in a great-looking guide complete with paper printing templates.

Our favorite part has to be the infinity mirror heart, which appears to be beating thanks to clever programming. That, and the costume details, like the waist-area wires running between the upper and lower pieces.

Is the party at your house? There’s probably still enough time to put together a projector-based stomping game for the driveway.