Month: May 2016

Beautiful Kegerator, Built The Hard Way

May 19, 2016 by 11 Comments

[Luke] brews his own beer. And like all beer brewers, he discovered that the worst part of homebrewing is cleaning out all the bottles. Time for a kegging system! And that means, time for a kegerator to keep the brew cold.

Normal kegerators are just a few holes drilled in an appropriate refrigerator. Most fridges have a step in the back where the compressor lives, which makes kegs an awkward fit, so [Luke] decided to build his own refrigerator.

He used beautiful wood and plenty of insulation. He failed, though, because he succumbed to the lure of the Peltier cooler. If there’s one problem with Peltier projects, it’s building first and looking up the specs second. They never have enough cool-juice. To quote [Luke]:

“… a comment I had seen somewhere on the Internet began to sink in: all projects involving peltier devices ultimately end in disappointment.“

(Bolding and italics from the original.) But at least he learned about defrosting, and he had a nice wood-paneled fridge-box in the basement.

Rather than give up, he found a suitable donor fridge, ripped out its guts, and transplanted them into his homemade box. A beautiful tap head sitting on top completes the look. And of course, there’s an ESP8266 inside logging the temperature and controlling the compressor, with all the data pushed out over WiFi. Try doing that with your Faraday Cage metal fridge!

We’ve seen kegerator builds before. Some of our favorites include this one that has a motorized retracting tap tower, and one that’s built into the walls of the house.

It’s Time For Direct Metal 3D-Printing

May 19, 2016 by 75 Comments

It’s tough times for 3D-printing. Stratasys got burned on Makerbot, trustful backers got burned on the Peachy Printer meltdown, I burned my finger on a brand new hotend just yesterday, and that’s only the more recent events. In recent years more than a few startups embarked on the challenge of developing a piece of 3D printing technology that would make a difference. More colors, more materials, more reliable, bigger, faster, cheaper, easier to use. There was even a metal 3D printing startup, MatterFab, which pulled off a functional prototype of a low-cost metal-powder-laser-melting 3D printer, securing $13M in funding, and disappearing silently, poof.

This is just the children’s corner of the mall, and the grown-ups have really just begun pulling out their titanium credit cards. General Electric is on track to introduce 3D printed, FAA-approved fuel nozzles into its aircraft jet engines, Airbus is heading for 3D-printed, lightweight components and interior, and SpaceX has already sent rockets with 3D printed Main Oxidizer Valves (MOV) into orbit, aiming to make the SuperDraco the first fully 3D printed rocket engine. Direct metal 3D printing is transitioning from the experimental research phase to production, and it’s interesting to see how and why large industries, well, disrupt themselves.

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Star Trek Material Science Is Finally Real: Transparent Wood

May 19, 2016 by 89 Comments

It’s not transparent aluminum, exactly, but it might be even better: transparent wood. Scientists at the University of Maryland have devised a way to remove all of its coloring, leaving behind an essentially clear piece of wood.

IMG_20160518_110605By boiling the block of wood in a NaOH and Na2SO chemical bath for a few hours the wood loses its lignin, which is gives wood its color. The major caveat here is that the lignin also gives wood strength; the colorless cellulose structure that remains is itself very fragile. The solution is to impregnate the transparent wood with an epoxy using about three vacuum cycles, which results in a composite that is stronger than the original wood.

There are some really interesting applications for this material. It does exhibit some haze so it is not as optimally transparent as glass but in cases where light and not vision is the goal — like architectural glass block — this is a winner. Anything traditionally build out of wood for its mechanical properties will be able to add an alpha color channel to the available options.

The next step is finding a way to scale up the process. At this point the process has only been successful on samples up to 1 centimeter thick. If you’re looking to build a starship out of this stuff in the meantime, your best bet is still transparent aluminum. We do still wonder if there’s a way to eliminate the need for epoxy, too.

$25 Satellite Tracker Boasts “Usefulness Optional”

May 19, 2016 by 54 Comments

[Paul] is very up-front about the realities of his $25 Satellite Tracker, which aims a tape measure yagi antenna at a satellite of choice and keeps it tracking the satellite as it moves overhead. Does it work? Yes! Is it cheap? Of course! Is it useful? Well… did we mention it works and it’s cheap?

When [Paul] found himself wanting to see how cheaply he could make a satellite tracker he already had an RTL-SDR (which we have seen used for satellite communication before) and a yagi antenna made out of a tape measure, but wanted some way to automatically point the antenna at a satellite as it moved across the sky. He also wanted to see just how economically it could be done. Turns out that with some parts from China and code from SatNOGS (open-source satellite tracking network project and winner of the 2014 Hackaday Prize) you have most of what you need! A few modifications were still needed, and [Paul] describes them all in detail.

Satellite Tracker In Parking Lot ThumbnailSo is a $25 Satellite Tracker useful? As [Paul] says, “Probably not.” He explains, “Most people want satellite trackers so that they can put them outside and then control the antenna from inside, which someone probably can’t do with mine unless they live in a really nice place or build a radome. […] Driving somewhere, setting it up correctly (which involves reprogramming the Arduino for every satellite), and then sitting around is pretty much the opposite of useful.”

It might not be the most practical but it works, it’s cool, he learned a lot, and he wrote up the entire process for others to learn from or duplicate. If that’s not useful, we don’t know what is.

Satellite tracking is the focus of some interesting projects. We’ve even seen a project that points out satellite positions by shining a laser into the sky.

Electromagnetic Field’s Badge Hanging In The Balance

May 18, 2016 by 5 Comments

Making conference badges is a tough job. Unless you’re sitting on a gold mine, you have to contact a whole bunch of sponsors for help, work the parts that you can get into a coherent design, and do it all on the quick for a large audience. The EMF team is this close to getting it done, but they need some sponsorship for the assembly. If you know anyone, help them out! If they can’t line something up in the next two weeks, they’ll have to pull the plug on the badge entirely.

Electromagnetic Field is a summer-camp hacker convention / festival that takes place in England and is now in its third iteration. As with other big cons, the badge is a good part of the fun.

The 2016 EMF badge looks to be amazing. It’s powered by an ST STM32L4 low-power micro, a color LCD screen, a TI CC3100 WiFi radio module onboard, and a ridiculous number of other features including a gyro and magnetometer, and a giant battery. It’s also a testbed for the brand-new MicroPython, which aims to bring everyone’s favorite scripting language to embedded processors. In fact, they’ve largely built the MicroPython WiFi drivers for the badge.

If they can’t get a sponsor, all is not lost because everything is open source. We’ll all reap the benefits of their hard work. But that’s not the point. The point is that hundreds of hackers will be standing around in a field outside of London without the most audacious badge that we’ve seen designed dangling from their necks.
If you know anyone who can help, get in touch?

Thanks [schneider] for the tip!

I2c Relay Expander Uses Nifty Card-Edge Connection

May 18, 2016 by 24 Comments

[Andrew Sowa] wanted to use an off-the-shelf relay board from Numato Labs. The board lacks a suitable computer interface, which meant that [Andrew] would have to build one, and its input connectors are screw terminals, which meant a lot of wiring. Undeterred, he created an i2c expansion board using an MCP23017 I/O port expander, and with a novel card-edge designed to mate with the screw terminals, solving both problems at once.
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Subsea ROV Has 6 Degrees Of Freedom + Autopilot

May 18, 2016 by 16 Comments

This is what happens when you give Norwegian engineering students half a year to develop an ROV for their class.

The team utilized 3D printing to design and print their own thruster propellers and ducts for the ROV. It’s powered by HobbyKing motors with VESC speed controllers. This allows them to get from 0.6 to 30N of thrust from each propeller at 12V. Because of this accuracy they’re able to use a PID system to do automatic pitch, roll and depth control!

The electronics are housed in a 200mm acrylic tube (15mm wall thickness) with aluminum end caps and o-rings — an exact pressure rating is not given, but the team could flood the chamber with non-conductive oil to increase that even more — they just don’t need to for tests in a swimming pool. The undersea wire connectors they use (Subconn) are rated for 700 and 600 bar!

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