Turning A Single Bolt Into A Combination Lock

July 18, 2019 by Dan Maloney 27 Comments

In our search for big-box convenience, we tend to forget that locksmiths once not only copied keys but also created complex locks and other intricate mechanisms from scratch. [my mechanics] hasn’t forgotten, and building a lock is his way of celebrating of the locksmith’s skill. Building a combination lock from a single stainless bolt is probably also showing off just a little, and we’re completely fine with that.

Granted, the bolt is a rather large one – an M20x70 – and a few other materials such as brass rod and spring wire were needed to complete the lock. But being able to look at a single bolt and slice it up into most of the stock needed for the lock is simply amazing. The head became the two endplates, while the shank was split in half lengthwise and crosswise after the threads were turned off; those pieces were later turned down into the tubes and pins needed to create the lock mechanism. The combination wheels probably could have come from another – or longer – bolt, but we like the look of the brass against the polished stainless, as well as the etched numbers and subtle knurling. The whole thing is a locksmithing tour de force, and the video below captures all of it without any fluff or nonsense.

If working in steel and brass isn’t your thing, fear not – a 3D-printed combination lock is probably within your reach. Or laser cut wood. Or even plain paper, if you’re not into the whole security thing.

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A (Card) Table-Top Turing Machine Of Magic: The Gathering Cards

July 18, 2019 by Roger Cheng 8 Comments

Within normal rules of collectible card game Magic: The Gathering a player may find themselves constrained to only a single legal course of action forward. It’s a situation players could craft to frustrate their opponents, though the victims usually break free after a few moves. But under a carefully crafted scenario, players would have no choice but to become the execution engine for a Turing-complete programming language written with Magic cards via techniques detailed in this paper.

One of the authors of this paper, [Alex Churchill], started working on this challenge in 2010. We covered an earlier iteration of his work here, and his own criticism that it was dependent on player cooperation. At various points, the game rules state a player “may” take certain actions and the construct falls apart if our player chooses the wrong thing. It would be as if a computer was built out of transistors that “may” switch as commanded or not, which would not be a very reliable method of computation.

To improve reliability of this particular Turing machine execution engine, the team combed through rules and cards to devise an encoding where the player is only ever presented with a single legal course forward. This ensures deterministic execution of the instruction stream, and now with proof of Turing-completeness in hand, we congratulate [Alex] on a successful conclusion to his decade-long quest.

We have a primer available for anyone who wants a refresher on Turing machines. They are utterly impractical but fun for hackers to build, and they are typically constructed of electronics and LEDs instead of ink on cardboard.

Via Ars Technica, who have presented their own analysis of this machine.

Main image: Unspecified set of Magic: The Gathering cards by [Robert] CC BY 2.0

Live Apollo 11 Transcript On EInk Display

July 18, 2019 by Tom Nardi 1 Comment

There are few moments in history that have ever been recorded in more detail or analyzed as thoroughly as the Apollo 11 mission to the Moon. Getting three men to our nearest celestial neighbor and back in one piece took a lot of careful planning, and recording every moment of their journey was critical to making sure things were going smoothly. As we celebrate the 50th anniversary of man’s first steps off our world, these records give us a way to virtually tag along with Armstrong, Aldrin, and Collins.

As part of the 50th anniversary festivities at the Parkes Radio Telescope in Australia, [Andrew] created a badge that would let him wear a little piece of Apollo 11. Using an ESP32 and an eInk screen, it replays the mission transcript between the crew and ground control in real-time. It’s a unique way to experience the mission made possible by that meticulous data collection that’s a hallmark of the National Aeronautics and Space Administration.

[Andrew] was inspired by the “Apollo 11 In Real Time” website, but rather than pulling the content from the Internet, he’s loaded the mission transcripts onto the ESP32’s SPIFFS filesystem as a CSV file. Not that the badge is completely offline, it does need to connect to the Internet (via a hotspot on his phone) so it can keep its internal clock synchronized with NTP. Keeping everything local does reduce power consumption compared to streaming it from the Internet, but he admits that otherwise he didn’t give much thought to energy efficiency and there’s definitely some room for improvement.

The LILYGO TTGO board he’s using combines the ESP32 with a 2.13 inch eInk display, in a formfactor not unlike the Badgy we’ve covered previously. He was able to find a STL for a 3D printed case on Thingiverse which he modified to fit a battery. Unfortunately the original model was released under a license that prevents him from distributing his modified version, but it doesn’t sound too difficult to replicate if you’re interested in building your own running ticker of humanity’s greatest adventure.

Put Those IPad Displays To Work With This EDP Adapter

July 18, 2019 by Tom Nardi 37 Comments

Regardless of how you might feel about Apple and the ecosystem they’ve cultured over the years, you’ve got to give them some credit in the hardware department. Their “Retina” displays are a perfect example; when they brought the 2,048 by 1,536 panel to the iPad 3, the technology instantly became the envy of every tablet owner. But what if you want to use one of these gorgeous screens outside of Apple’s walled garden?

As it turns out, there are a number of options out there to use these screens on other devices, but [Arthur Jordan] wasn’t quite happy with any of them. So he did what any self respecting hacker would do, and built his own adapter for iPad 3 and 4 screens. Not that he did it completely in the dark; his design is based on the open source Adafruit Qualia driver, which in turn was based on research done by [Mike’s Mods]. A perfect example of the open source community at work.

The resulting board allows you to connect the Retina display from the iPad 3 or 4 to any device that features Embedded DisplayPort (eDP). Rather than put a dedicated port on his board, [Arthur] just left bare pads where you can solder up whatever interface method your particular gadget might use. In his case, he wanted to hook it up to an x86 UP Core SBC, so he even came up with a seperate adapter that breaks out that board’s diminutive display connector to something that can be soldered by hand.

So what’s different between the board [Arthur] developed and Adafruit’s Qualia? Primarily its been made smaller by deleting the DisplayPort connectors in favor of those bare pads, but he’s also dumped the backlight control hardware and 3.3V regulator that in his experience hasn’t been necessary with the eDP devices he’s worked with. So if space is a concern in your build, this version might be what you’re after.

We’ve seen other Retina display adapters in the past, and of course the iPad isn’t the only high-end device that’s had a screen good enough to reuse on its own. The lesson here is that if you put a must-have feature in your product, don’t be surprised when some hacker comes along and figures out how to liberate it for their own purposes.

Getting Hackers Excited About Cable Robots

July 18, 2019 by Tom Nardi 22 Comments

Ever since he looked into them as a way to water and care for his plants, [Tom] has been fascinated with cable robots. These high-flying gadgets can move in three dimensions over huge areas, provided you’ve got the ability to string up the aforementioned cables. But despite their flexibility, there hasn’t been a whole lot of hobbyist level development with these unique systems.

With his entry into the 2019 Hackaday Prize, [Tom] is hoping to change that. He’s learned a lot by building his own cable robots, and now wants to take it to the next level. Ideally with collaboration from the community, if he can find other hackers looking to outfit their homes or workshops with their own miniature sky cranes.

So what can you do with a cable robot? In the video after the break, [Tom] shows one of his creations dutifully transporting beer cans across the room and stacking them into a pyramid. Admittedly this isn’t a particularly useful capability (unless you run a bar, perhaps), but it does show the speed and dexterity of the system even when crossing large distances. If you’ve ever wanted to play the home edition of “Automate the Freight”, this one’s for you.

The system uses a trio of 36 volt stepper motors powered by a homebrew SLA7078 driver that [Tom] designed himself. Each stepper turns a geared-down spindle to which a strong cable is attached. With some clever routing around the workspace, careful orchestration of these small winches can be used to move the point where all the cables meet in 3D space. All that’s left is mounting your gadget of choice to this central point, and away you go.

We’ve seen the concept used commercially, but as far as hobbyist projects go, the most activity we’ve seen in this space would have to be the various room sized 3D printers that have popped up over the years. It would be interesting to see what kind of interesting projects the community could come up with if they had something with a little more muscle.

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Hacking Shelters And Swimming Pools

July 18, 2019 by Al Williams 44 Comments

How would you survive in a war-torn country, where bombs could potentially fall from the sky with only very short notice? And what if the bomb in question were The Bomb — a nuclear weapon? This concern is thankfully distant for most of us, but it wasn’t always so. Only 75 years ago, bombs were raining down on England, and until much more recently the threat of global thermonuclear war was encouraging school kids to “duck and cover”. How do you protect people in these situations?

The answers, naturally, depend on the conditions at hand. In Britain before the war, money was scarce and many houses didn’t have basements or yards that were large enough to build a family-sized bomb shelter in, and they had to improvise. In Cold War America, building bomb shelters ended up as a boon for the swimming pool construction industry. In both cases, bomb shelters proved to be a test of engineering ingenuity and DIY gumption, attempting to save lives in the face of difficult-to-quantify danger from above.

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Project Egress: The Hinges

July 18, 2019 by Dan Maloney 34 Comments

A door’s hinges are arguably its most important pieces. After all, a door without hinges is just, well, a wall. Or a bulkhead, if we’re talking about a hingeless hatch on a spacecraft.

And so the assignment for creating hinges for Progress Egress, the celebration of the 50th anniversary of the Apollo 11 landing by creating a replica of the command module hatch, went to [Jimmy DiResta]. The hinges were complex linkages that were designed to not only handle the 225 pound (102 kg) hatch on the launch pad, but to allow extended extravehicular activity (EVA) while en route to the Moon. [Jimmy], a multimedia maker, is just as likely to turn metal as he is to work in wood, and his hinges are a study of 1960s aerospace engineering rendered in ipe, and extremely hard and dense tropical hardwood, and brass.

[Jimmy]’s build started with a full-size 3D-printed model of the hinge, a move that paid off as the prints acted both as templates for machining the wood components and as test jigs to make sure everything would articulate properly. Sheet brass was bent and soldered into the hinge brackets, while brass rod stock was turned on the lathe to simulate the hydraulic cylinder hinge stays of the original. The dark ipe and the brass work really well together, and should go nicely with [Fran Blanche]’s walnut and brass latch on the assembled hatch.

With [Adam Savage]’s final assembly of all the parts scheduled for Thursday the 18th, we’re down to the wire on this celebration of both Apollo and the maker movement that was at least in part born from it.

Note: the assembly started at 11:00 Eastern time, and there’s a live stream at https://airandspace.si.edu/events/project-egress-build.

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