Day: February 28, 2018

Detoured: Fabbing At The Art Institute Of Chicago

February 28, 2018 by 11 Comments

[Majenta Strongheart] is one of the talented folks who works at the SupplyFrame Design Lab, home to dozens of Hackaday meetups, the Hackaday Superconference, and when the shop floor isn’t filled with chairs, is the place where tons of awesome projects are fabricated. [Majenta]’s role at the Design Lab is a Staff Designer, where she’s responsible for working the machines, and holds the distinction of being in the room when the SawStop kicked for the first time. Don’t fret: it was mirrored acrylic.

Among [Majenta]’s other duties at the Design Lab is on the social media front, showing off the capabilities of other design spaces around the country. Her first video in this series is from her alma mater, the Art Institute of Chicago. In this video, [Majenta] takes a look at the incredible fabrication facilities found here.

The tour begins in an exceptionally well-equipped wood shop kitted out with panel saws, spindle sanders, bandsaws, and not enough clamps. From there, the tour moves over to the metal shop and — unique for the city of Chicago — a forge. A long time ago, after Philadelphia and New York were the tech centers of America, and before the Bay Area was the tech center of America, Chicago made everything. The forge at the Art Institute of Chicago is the last remaining place in the city where metal casting takes place. This space was grandfathered in, and still remains a place where students can cast objects out of bronze and aluminum.

The Art Institute of Chicago is a very, very well equipped space full of enough tools to make anything you want. If you’re looking for some inspiration on what your basement, garage, or local hackerspace should look like, you need only look at [Majenta]’s tour. You can check out the entire video below.

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Building A Portable Solar Powered Spot Welder: Charging Supercapacitors

February 28, 2018 by 48 Comments

Before Lunar New Year, I had ordered two 3000 F, 2.7 V supercapacitors from China for about $4 each. I don’t actually remember why, but they arrived (unexpectedly) just before the holiday.

Supercapacitors (often called ultracapacitors) fill a niche somewhere between rechargeable lithium cells and ordinary capacitors. Ordinary capacitors have a low energy density, but a high power density: they can store and release energy very quickly. Lithium cells store a lot of energy, but charge and discharge at a comparatively low rate. By weight, supercapacitors store on the order of ten times less energy than lithium cells, and can deliver something like ten times lower power than capacitors.

Overall they’re an odd technology. Despite enthusiastic news coverage, they are a poor replacement for batteries or capacitors, but their long lifespan and moderate energy and power density make them suitable for some neat applications in their own right. Notably, they’re used in energy harvesting, regenerative braking, to extend the life of or replace automotive lead-acid batteries, and to retain data in some types of memory. You’re not likely to power your laptop with supercapacitors.

Anyway, I had a week-long holiday, and two large capacitors of dubious origin. Sometimes we live in the best of all possible worlds. Continue reading “Building A Portable Solar Powered Spot Welder: Charging Supercapacitors” →

Teardown Of An UWB Location Beacon

February 28, 2018 by 10 Comments

Outdoor navigation is a problem that can be considered solved for decades or maybe even centuries, depending on the levels of accuracy, speed and accessibility required. Indoor navigation and location, on the other hand, is a relatively new field and we are still figuring it out. Currently there are at least four competing technologies pushed by different manufacturers. One is ultra wide band radio and [Marco van Nieuwenhoven] shows us what a beacon using this technology is made of.

In his thorough tear down of an Estimote location beacon, he comes up with a complete parts list and schematics for each of the four PCB layers. The beacons are controlled by a Cortex M4 and feature Bluetooth radio in addition to the UWB part. They also come with a three-axis accelerometer, temperature, ambient light and pressure sensors and NFC capability. These boards combine a lot of functionality in a compact package and [Marco]’s stated intent is to create an open source firmware for them.

Hacking proprietary hardware, especially when doing so in public may get you in legal trouble, but in this case [Marco] has contacted the manufacturer, and the relationship seems to be friendly so far. Let’s hope it stays that way; these things look like a promising platform and may become a lower cost alternative to the evaluation kit running the same UWB radio we featured earlier. Alternatively you could ditch the UWB and use WiFi for indoor location.

Cook Up Your Own High-Temperature Superconductors

February 28, 2018 by 16 Comments

It looks more like a charcoal briquette than anything, but the black brittle thing at the bottom of [Ben Krasnow]’s crucible is actually a superconducting ceramic that can levitate magnets when it’s sitting in liquid nitrogen. And with [Ben]’s help, you can make some too.

Superconductors that can work at the relatively high temperature of liquid nitrogen instead of ultracold liquid helium are pretty easy to come by commercially, so if you’re looking to just float a few magnets, it would be a lot easier to just hit eBay. But getting there is half the fun, and from the look of the energetic reaction in the video below, [Ben] had some fun with this. The superconductor in question here is a mix of yttrium, barium, and copper oxide that goes by the merciful acronym YBCO.

The easy way to make YBCO involves multiple rounds of pulverizing yttrium oxide, barium chloride carbonate, and copper oxide together and heating them in a furnace. That works, sort of, but [Ben] wanted more, so he performed a pyrophoric reaction instead. By boiling down an aqueous solution of the three components, a thick sludge results that eventually self-ignites in a spectacular way. The YBCO residue is cooked in a kiln with oxygen blowing over it, and the resulting puck has all the magical properties of superconductors. There’s a lot of detail in the video, and the experiments [Ben] does with his YBCO are pretty fascinating too.

Things are always interesting in [Ben Krasnow]’s life, and there seem to be few areas he’s not interested in. Of course we’ve seen his DIY CAT scanner, his ruby laser, and recently, his homemade photochromic glass.

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