32C3: 3D Printing On The Moon

January 3, 2016 by Elliot Williams 36 Comments

How do you resist this talk title? You can’t! [Karsten Becker]’s talk about what kinds of 3D printers you’d use on the moon is a must-see.

[Part-Time Scientists] was a group of 35 people working on a mission to the moon. Then they won the qualifying round in the Google Lunar XPRIZE, got a bunch of money, and partnered with some heavy corporate sponsors, among which is Audi. Now they’ve added eleven full-time employees and updated the name to [PT Scientists]. (They’re taking applications if you’re interested in helping out!)

A really neat part of their planned mission is to land near the Apollo 17 landing site, which will let them check up on the old lunar rover that NASA left up there last time. The science here is that, 45 years on, they hope to learn how all of the various materials that make up the rover have held up over time.

But the main attraction of their mission is experimental 3D printing using in-situ materials. As [Karsten] says, “3D printing is hard…but we want to do it on the moon anyway.”

One idea is to essentially microwave the lunar regolith (and melt it) . This should work because there’s a decent iron component in the regolith, so if they can heat it up it should fuse. The catch with microwaving is directivity — it’s hard to make fine details. On the plus side, it should be easy to make structures similar to paved roads out of melted regolith. Microwave parts are robust and should hold up to launch, and microwaving is relatively energy efficient, so that’s what they’re going to go for.

But there are other alternatives. The European Space Agency is planning to bring some epoxy-like binder along, and glue regolith together in layers like a terrestrial cement printer. The problem is, of course, schlepping all of the binder to the moon in the first place.

And then there are lasers. [Karsten] talked lasers down a little bit, because they’re not very energy efficient and the optics are fidgety — not something you’d like to be supporting remotely from earth.

The final option that [Karsten] mentioned was the possibility of using locally-generated thermite to fuse regolith. This has been tested out on earth, and should work. [Karsten] thought it was an interesting option, but balls of hot thermite are potentially tough on rovers, and the cost of mistakes are so high that they’re going to put that off for a future mission.

In the end, the presentation ran only thirty minutes long, so there’s a great Q&A session after that. Don’t go home once you hear the audience clapping!

The Mystery Of The Boiled Batteries

January 2, 2016 by Elliot Williams 44 Comments

While debugging a strange battery failure in a manufacturing process, [Josh] discovered a new (to us) LiPo battery failure mode.

Different battery chemistries react differently to temperature. We’ve used lithium exclusively in high-altitude ballooning, for instance, because of their decent performance when cold. Lithium batteries generally don’t like high temperatures, on the other hand, but besides the risk of bursting into flames, we had no idea that heat could kill them. When the battery’s voltage is already low, though, it turns out it can.

[Josh]’s process required molding plastic with the battery inside, and this meant heating the batteries up. After the fact, he noticed an unreasonably high failure rate in the batteries, and decided to test them out. He put the batteries, each in a different initial charge, into a plastic bag and tortured them all with ice and fire. (OK, boiling water.)

When the batteries got hot, their voltage sagged a little bit, but they recovered afterwards. And while the voltage sagged a little bit more for the batteries with lower initial charge, that’s nothing compared to the complete failure of the battery that entered the hot water with under 1V on it — see they yellow line in the graphs.

There’s a million ways to kill a battery, and lithium batteries are known not to like being completely discharged, but it looks like the combination of deep discharge and heat is entirely deadly. Now you know.

Help Needed: No-Soldering ESP8266 IFTTT Button

January 1, 2016 by Elliot Williams 18 Comments

We all love to see amazing hacks in their finished state and be dazzled by what our peers can do. But that’s just the summit of the hacker’s Everest. We all know that the real work is in getting there. Hackaday.io user [stopsendingmejunk] is working on an ESP8266-based IFTTT Button based on a simple breakout board so that anyone could rebuild it without having to do any soldering, and he’s looking for collaboration.

[stopsendingmejunk]’s project takes off from this similar project on different hardware. The board he’s chosen to use is the EZSBC ESP8266-07 breakout, which should have everything he needs, including an on-board button. It should be an easy enough job, but he’s having trouble getting the thing to stay asleep until the button is pressed.

We’ve seen more than a few hacks of the Amazon Dash button, but aside from hacking for hacking’s sake, we’re also happy to see a ground-up open redesign. Besides, this looks like it’ll be a great introductory project, requiring little fiddling around. With a little help. The code is up here on GitHub. Anyone game?

Hillbilly Lego Focus Puller

January 1, 2016 by Elliot Williams 10 Comments

There’s almost nothing you can’t build with the right set of Lego parts. [Rigjob] built up a Lego-based wireless remote follow-focus system that’ll give professional systems a run for their money.

Now [Rigjob] self-identifies as a hillbilly, but he’s not just a redneck with a camera. He’s set up the Lego controller to remember minimum and maximum focus positions as well as mark points along the way. The controller simply won’t turn the lens outside of the focus range, and an interactive graph shows you where you are within the range. For a focus wheel, he uses (drum-roll please!) a Lego off-road wheel. It looks really comfortable, usable, and actually quite professional.

There’s a lot of tech in the Lego controller and motors that make this “simple” hack simple. Under the hood, there’s a Bluetooth connection, a geared stepper motor with a position sensor, a communication protocol, and a whole ton of programming in the Lego controller that makes it all drag-and-drop programmable. But to a long-bearded hillbilly cameraman, it all looks like child’s play. And that’s the hallmark of good design. Kudos, Lego.

If you can’t get enough Lego camera tech, check out this DIY slit-scan stargate rig, or (what else?) a Lego 3D chocolate printer.

Continue reading “Hillbilly Lego Focus Puller” →

EZ-Spin Motor Spins “Forever”

January 1, 2016 by Elliot Williams 90 Comments

Now this isn’t a perpetual motion machine, but it’s darn close. What [lasersaber] has done instead is to make the EZ Spin, an incredibly efficient motor that does nothing. Well, nothing except look cool, and influence tons of people to re-build their own versions of it and post them on YouTube.

The motor itself is ridiculously simple: it’s essentially a brushless DC motor with a unique winding pattern. A number of coils — anywhere from six to twenty-four — are wired together with alternating polarity. If one coil is a magnetized north, its two neighbors are magnetized south, and vice-versa. The rotor is a ring with permanent magnets, all arranged so that they have the same polarity. A capacitor is used for the power source, and a reed switch serves as a simplistic commutator, if that’s even the right term.

As the motor turns, a permanent magnet passes by the reed switch and it makes the circuit. All of the electromagnets, which are wound in series, fire and kick the rotor forwards. Then the reed switch opens and the rotor coasts on to the next position. When it gets there the reed switch closes and it gets a magnetic kick again.

The catch? Building the device so that it’s carefully balanced and running on really good (sapphire) bearings, entirely unloaded, and powered with high impedance coils, leads to a current consumption in the microamps. As with most motors, when you spin it by hand, it acts as a generator, giving you a simple way to charge up the capacitor that drives it. In his video [lasersaber] blows on the rotor through a straw to charge up the capacitor, and then lets it run back down. It should run for quite a while on just one spin-up.

The EZ Spin motor is absolutely, positively not perpetual motion or “over-unity” or any of that mumbo-jumbo. It is a cool, simple-to-build generator/motor project that’ll definitely impress your friends and challenge you to see how long you can get it running. Check out [lasersaber]’s website, this forum post, and a 3D model on Thingiverse if you want to make your own.

Continue reading “EZ-Spin Motor Spins “Forever”” →

32C3: My Robot Will Crush You With Its Soft Delicate Hands!

January 1, 2016 by Elliot Williams 2 Comments

In his talk at 32C3 [Matthew Borgatti] talked both about his company’s work with NASA toward developing robotic spacesuits and helping people with Cerebral Palsy better control their limbs. What do these two domains have in common? “One-size fits all pneumatic exoskeletons.”

[Matthew] makes a tremendously compelling case for doing something new and difficult in robotics — making robotic systems out of squishy, compliant materials. If you think about it, most robots are hard: made of metal and actuated by motors and gears, cables, or (non-compressible) pneumatic fluid. If you want to build suits that play well with soft and squishy people, they’ll need at least a layer of softness somewhere.

But [Matthew]’s approach is to make everything soft. In the talk, he mentions a few biological systems (octopus arms and goat’s feet) that work exactly because they’re soft. Why soft? Because soft spreads force around automatically and accommodates uneven terrain. And this makes it easier on the people who wear robotic suits and on the designers of the robots who don’t need to worry about the fine detail of the ground they’re walking on.

The talk ended up being very short, but there’s a fantastic Q&A at the end. It’s a must-see. And if you can’t get enough of [Matthew] or squishy robots, we’ve covered his robots before and he even had an entry in the Hackaday Prize.

Art For Planespotters

December 31, 2015 by Elliot Williams 6 Comments

We don’t know art, but we know what we like. And this gizmo by [Johan Kanflo] is right up our alley.

First, [Johan] gutted an old Macintosh Classic computer and stuffed a Raspberry Pi inside. Now this is not really a new idea, but [Johan] did a very nice job with the monitor and his attention to detail shows in the rebuilt floppy-drive eject mechanism. He gives it back that characteristic “schlurp” noise.

Then he outfitted the Raspberry Pi with an RTL dongle running dump1090 software to listen to the ADS-B radio signals. The data extracted from the SDR is piped off to an MQTT server with all sorts of data about the airplanes overhead. Another script subscribes to the MQTT topic and figures out which is the closest and runs an image search for the plane type in question, publishing the results back to another MQTT topic. One final script subscribes to this last topic and displays the relevant images on the screen. Pshwew!

The end result is a Macintosh Classic that’s continually updated with whatever planes are closest to being overhead. We’re not at all sure if this is fine art, or part of the useful arts, or maybe even none of the above. But we really like the nice case job and think that using MQTT as a back-end for coordinating multiple concurrent Python scripts (on the same computer) is pretty cool.