Building A 3D Printer That Goes Where You Do

Back when one of the best paths to desktop 3D printer ownership was building the thing yourself from laser cut wood with some string thrown in for good measure, just saying you had one at home would instantly boost your hacker street cred. It didn’t even need to work particularly well (which is good, since it probably didn’t), you just had to have one. But now that 3D printers have become so common, the game has changed. If you want to keep on the cutting edge, you’ve got to come up with a unique hook.

Luckily for us, [Thomas Sanladerer] is here to advance the status quo of desktop 3D printing. Not content with a 3D printer that spends its time loafing around the workshop, he decided to build a completely mobile 3D printer. For a guy who spends a lot of time traveling to different 3D printing conferences and shows, this is actually a pretty handy thing to have around, but there are probably some lessons to be learned here even if you aren’t a 3D printing YouTube celebrity.

Given the wide array of very popular low cost 3D printers out there, some will likely be surprised that [Thomas] decided to mobilize a printer which is nearly an antique at this point: the PrinterBot Play. But as he explains in the video after the break, the design of the Play really lends itself perfectly to life on the road. For one, it’s an extremely rigid printer thanks to its (arguably overkill) steel construction. Compared to most contemporary 3D printers which are often little more than a wispy collection of aluminium extrusion and zip ties, the boxy design of the Play also offers ample room inside for additional electronics and wiring

The most obvious addition to the PrintrBot is the six Sony NP-F camera batteries that [Thomas] attaches to the back of the printer by way of 3D printed mounts, but there’s also quite a bit of hardware hidden inside to break the machine free from its alternating current shackles. The bank of batteries feed simultaneously into a DC boost converter which brings the battery voltage up to the 12 V required for the printer’s electronics and motors, and a DC regulator which brings the voltage down to the 5 V required by the Raspberry Pi running OctoPrint. There’s even a charge controller hiding in there which not only frees him from carrying around a separate charger, but lets him top up the cells while the printer is up and running.

On the software side of things, the Raspberry Pi is configured to work as a WiFi access point so that OctoPrint can be controlled with a smartphone even if there’s no existing network in place. A fact demonstrated when he takes the printer outside for a walk while it’s in the middle of a job. The ability to control the printer without any existing infrastructure combined with the estimated six hour runtime on a charge means this modified PrinterBot can get the job done no matter where [Thomas] finds himself.

The hacker community was saddened by the news that PrintrBot was closing its doors last year, an unfortunate casualty of an increasingly competitive desktop 3D printing market. But perhaps we can take some comfort from the fact that their eminently hackable open source printers still live on in projects such as this.

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Automate Your Home From the Clearance Rack

The month or so after the holidays have always been a great time to pick up some interesting gadgets on steep clearance, but with decorations and lights becoming increasingly complex over the last few years, the “Christmas Clearance” rack is an absolute must see for enterprising hackers. You might just luck out like [ModernHam] and find a couple packs of these dirt cheap wireless light controllers, which can fairly easily be hacked into the start of a home automation system with little more than the Raspberry Pi and a short length of wire.

In the video after the break, [ModernHam] walks the viewer through the start to finish process of commanding these cheap remote plugs. Starting with finding which frequencies the remotes use thanks to the FCC database and ending with using cron to schedule the transmission of control signals from the Pi, his video really is a wealth of information. Even if you don’t have this particular model of remote plug, or don’t necessarily want to setup a home automation system, there’s probably some element of this video that you could still adapt to your own projects.

The first step of the process is figuring out how the remote is communicating to the plugs. [ModernHam] noticed there was no frequency listed on the devices, but using their FCC IDs he was able to find the relevant information. In the United States, devices like these must have their FCC IDs visible (though they could be behind a battery door) by law, so the searchable database is an invaluable tool to do some basic reconnaissance on a poorly documented gadget.

An RTL-SDR receiver is then used to fine tune the information gleaned from the FCC filing. [ModernHam] found that the signals for all four of the remote plugs were being broadcast on the same frequency, which makes controlling them all the easier. Using the rtl-sdr command, he was able to capture the various signals from the transmitter and save them to separate files. Then it’s just a matter of replaying the appropriate file to get the plugs to do your bidding.

Of course, the RTL-SDR can’t transmit so you’ll have to leave your dongle behind for this last step. Luckily all you need to transmit is the rpitx package created by [F5OEO], along with a supported Raspberry Pi and a small length of wire attached to the appropriate GPIO pin. This package contains the tool sendiq which can be used to replay the raw captures made in the previous step. With some scripting, it’s fairly straightforward to automate these transmissions to control the remote plugs however you wish from the Pi.

The RTL-SDR Blog put together their own guide for “brute forcing” simple remote control devices like this as well, and we’ve even seen similar techniques used against automotive key fobs in the past. Amazing what a piece of wire and some clever code can pull off.

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An Arduino Carbon Fiber Wrapping Machine

Many of the projects we feature on Hackaday are motivated by pure greed. Not on the part of the hacker, mind you; but rather the company that’s charging such an outrageous price for a mass produced item that somebody decides they can do the same thing cheaper as a one-off project. Which is precisely how [Bryan Kevan] ended up building his own carbon fiber tube wrapping machine. Not only do the finished tubes look fantastic, but they cost him a fraction of what even the “cheap” commercial ones cost.

The principle behind producing the tubes is really pretty simple: carbon fiber ribbon (or “tow”, in the official parlance) gets wrapped around a rotating mandrel, ideally in interesting patterns, and epoxy is added to bind it all together. When it’s hardened up, you slide the new carbon fiber tube off the mandrel and away you go building a bike frame or whatever it is you needed light and strong tubes for. You could even do it by hand, if you had enough patience.

[Bryan] had done it by hand before, but was looking for a way to not only automate the process but make the final product a bit more uniform-looking. His idea was to rotate a horizontal PVC pipe as his mandrel, and move a “car” carrying the carbon fiber ribbon back and forth along its length. The PVC pipe just needs to rotate along its axis so he figured that would be easy enough; and using a GT2 belt and some pulleys, getting the carbon-laying car moving back and forth didn’t seem like much of a challenge either.

The frame of the winder is built from the hacker’s favorite: 20/20 aluminum extrusion. Add to that an Arduino Uno, two stepper motors with their appropriate drivers, and the usual assortment of 3D printed odds and ends. [Bryan] says getting the math figured out for generating interesting wrap patterns was a bit tricky and took a fair amount of trial and error, but wasn’t a showstopper. Though we’d suggest following his example and using party ribbon during testing rather than the carbon stuff, as producing a few bird nests at the onset seems almost a guarantee.

One of the trickiest parts of the project ended up being removing the carbon fiber tubes from the PVC mandrel once they were done. [Bryan] eventually settled on a process which involved spraying the PVC with WD-40, wrapping it in parchment paper, and then using a strip of 3M blue painter’s tape to keep the parchment paper from moving. If you can toss the whole mandrel in the freezer after wrapping to shrink it down a bit, even better.

So was all this work worth it in the end? [Bryan] says he was originally looking at spending up to $70 USD per foot for the carbon fiber tubes he needed for his bike frame, but by buying the raw materials and winding them himself, he ended up producing his tubes for closer to $3 per foot. Some might question the strength and consistency of these DIY tubes, but for a ~95% price reduction, we’d be willing to give it a shot.

Years ago we covered a Kickstarter campaign for a very similar carbon winder. Probably due to the relatively limited uses of such a gadget, the winder didn’t hit the funding goal. But just like the current wave of very impressive homebrew laser cutters, the best results might come from just building the thing yourself.

Arduino Tachometer Clock Fires on All Cylinders

We’re certainly no strangers to unique timepieces around these parts. For whatever reason, hackers are obsessed with finding new and interesting ways of displaying the time. Not that we’re complaining, of course. We’re just as excited to see the things as they are to build them. With the assumption that you’re just as enamored with these oddball chronometers as we are, we present to you this fantastic digital tachometer clock created by [mrbigbusiness].

The multi-function digital gauge itself is an aftermarket unit which [mrbigbusiness] says you can get online for as little as $20 from some sites. All he needed to do was figure out how to get his Arduino to talk to it, and come up with some interesting way to hold it at an appropriate viewing angle. The mass of wires coming out of the back of the gauge might look intimidating, but thanks to his well documented code it shouldn’t be too hard to follow in his footsteps if you were so inclined.

Hours are represented by the analog portion of the gauge, and the minutes shown digitally were the speed would normally be displayed. This allows for a very cool blending of the classic look of an analog clock with the accuracy of digital. He’s even got it set up so the fuel indicator will fill up as the current minute progresses. The code also explains how to use things like the gear and high beam indicators, so there’s a lot of room for customization and interesting data visualizations. For instance, it would be easy to scrap the whole clock idea and use this gauge as a system monitor with some modifications to the code [mrbigbusiness] has provided.

The gauge is mounted to a small project box with some 3D printed brackets and bits of metal rod, complete with a small section of flexible loom to cover up all the wires. Overall it looks very slick and futuristic without abandoning its obvious automotive roots. Inside the base [mrbigbusiness] has an Arduino Nano, a DS1307 RTC connected via I2C, a voltage regulator, and a push button to set the time. It’s a perfectly reasonable layout, though we wonder if it couldn’t be simplified by using an ESP8266 and pulling the time down with NTP.

We’ve seen gauges turned into a timepiece before, but we have to admit that this is probably the most practical realization we’ve seen of the idea yet. Of course if you want to outfit the garage with something a bit more authentic, you can always repurpose a Porsche brake rotor.

Inventors Chasing Their Dreams; What It’s Like to Quit Your Job and Hack

The phrase “Hindsight is 20/20” is one of those things that we all say from time to time, but rarely have a chance to truly appreciate to the fullest. Taken in the most literal context, it means that once you know the end result of a particular scenario, you can look back and clearly see the progression towards that now inescapable endgame. For example, if you’re stuck on the couch with a bad case of food poisoning, you might employ the phrase “Hindsight is 20/20” to describe the decision a few days prior to eat that food truck sushi.

Then again, it’s usually not that hard to identify a questionable decision, with or without the benefit of foreknowledge. But what about the good ones? How can one tell if a seemingly unimportant choice can end up putting you on track for a lifetime of success and opportunity? If there’s one thing Michael Rigsby hopes you’ll take away from the fascinating retrospective of his life that he presented at the 2018 Hackaday Superconference, it’s that you should grab hold of every opportunity and run with it. Some of your ideas and projects will be little more than dim memory when you look back on them 50 years later, but others might just end up changing your life.

Michael Rigsby’s electric car in 1971

Of course, it also helps if you’re the sort of person who was able to build an electric car at the age of nineteen, using technology which to modern eyes seems not very far ahead of stone knives and bear skins. The life story Michael tells the audience, complete with newspaper cuttings and images from local news broadcasts, is one that we could all be so lucky to look back on in the Autumn of our years. It’s a story of a person who, through either incredible good luck or extraordinary intuition, was able to be on the forefront of some of the technology we take for granted today before most people even knew what to call it.

From controlling his TRS-80 with his voice to building a robotic vacuum cleaner years before the Roomba was a twinkle in the eye of even the most forward thinking technofetishist, Michael was there. But he doesn’t hold a grudge towards the companies who ended up building billion dollar industries around these ideas. That was never what it was about for him. He simply loves technology, and wanted to show his experiments to others. Decades before “open source” was even a term, he was sharing his designs and ideas with anyone who’d care to take a look.

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Scramjet Engines on the Long Road to Mach 5

When Charles “Chuck” Yeager reached a speed of Mach 1.06 while flying the Bell X-1 Glamorous Glennis in 1947, he became the first man to fly faster than the speed of sound in controlled level flight. Specifying that he reached supersonic speed “in controlled level flight” might seem superfluous, but it’s actually a very important distinction. There had been several unconfirmed claims that aircraft had hit or even exceeded Mach 1 during the Second World War, but it had always been during a steep dive and generally resulted in the loss of the aircraft and its pilot. Yeager’s accomplishment wasn’t just going faster than sound, but doing it in a controlled and sustained flight that ended with a safe landing.

Chuck Yeager and his Bell X-1

In that way, the current status of hypersonic flight is not entirely unlike that of supersonic flight prior to 1947. We have missiles which travel at or above Mach 5, the start of the hypersonic regime, and spacecraft returning from orbit such as the Space Shuttle can attain speeds as high as Mach 25 while diving through the atmosphere. But neither example meets that same requirement of “controlled level flight” that Yeager achieved 72 years ago. Until a vehicle can accelerate up to Mach 5, sustain that speed for a useful period of time, and then land intact (with or without a human occupant), we can’t say that we’ve truly mastered hypersonic flight.

So why, nearly a century after we broke the sound barrier, are we still without practical hypersonic aircraft? One of the biggest issues historically has been the material the vehicle is made out of. The Lockheed SR-71 “Blackbird” struggled with the intense heat generated by flying at Mach 3, which ultimately required it to be constructed from an expensive and temperamental combination of titanium and polymer composites. A craft which flies at Mach 5 or beyond is subjected to even harsher conditions, and it has taken decades for material science to rise to the challenge.

With modern composites and the benefit of advanced computer simulations, we’re closing in on solving the physical aspects of surviving sustained hypersonic flight. With the recent announcement that Russia has put their Avangard hypersonic glider into production, small scale vehicles traveling at high Mach numbers for extended periods of time are now a reality. Saying it’s a solved problem isn’t quite accurate; the American hypersonic glider program has been plagued with issues related to the vehicle coming apart under the stress of Mach 20 flight, which heats the craft’s surface to temperatures in excess of 1,900 C (~3,500 F). But we’re getting closer, and it’s no longer the insurmountable problem it seemed a few decades ago.

Today, the biggest remaining challenge is propelling a hypersonic vehicle in level flight for a useful period of time. The most promising solution is the scramjet, an engine that relies on the speed of the vehicle itself to compress incoming air for combustion. They’re mechanically very simple, and the physics behind it have been known since about the time Yeager was climbing into the cockpit of the X-1. Unfortunately the road towards constructing, much less testing, a full scale hypersonic scramjet aircraft has been a long and hard one.

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Particle Paves Way For LTE Selfies

From cars to refrigerators, it seems as if every new piece of tech is connected to the Internet. For better or for worse, we’re deep into the “Internet of Things”. But what about your camera? No, not the camera in your smartphone; that one’s already connected to the Internet and selling your secrets to the highest bidder. Don’t you think your trusty DSLR could be improved by an infusion of Wide Area Networking?

Regardless of what you’re answer to that question might be, [Thomas Kittredge] decided his life would be improved by making his beloved Canon EOS Rebel T6 an honorary member of the Internet of Things. Truth be told he says that he hasn’t quite figured out an application for this project. But since he was looking to mess around with both the LTE-enabled Particle Boron development board and designing his own PCB for professional production, this seemed a good a way to get his feet wet as any.

The resulting board is a fairly simple “shield” for the Particle Boron that let’s [Thomas] trigger up to two cameras remotely over the Internet or locally with Bluetooth. If LTE isn’t your sort of thing though, don’t worry. Since the Boron follows the Adafruit Feather specification, there’s a whole collection of development boards with various connectivity options that this little add-on can be used with.

In the GitHub repository, [Thomas] has put up the files for the PCB, the STLs for the 3D printed enclosure, and of course the firmware source code to load onto the Particle board. He currently has code to expose the two shutter triggers as functions the the Particle Cloud API, as well as a practical example that fires off the camera when specific words are used in a Slack channel.

Out for a little over a year, the Particle Boron is a fairly new addition to the world of cellular development boards. Historically we haven’t seen a whole lot of cellular capable projects, likely because it’s been such a hassle to get them online, but with new boards like the Boron we might start seeing an uptick in the random pieces of gear that have this form connectivity and an internet-facing IP address. Surely nothing bad could come of this!