Tracked RC Vehicle Is (Mostly) 3D Printed

March 17, 2022 by 2 Comments

While wheels might seem like a foundational technology, they do have one major flaw: they typically need maintained roads in order to work. Anyone who has experience driving a Jeep or truck off-road likely knows this first-hand. For those with extreme off-road needs the track is often employed. [Let’s Print] is working on perfecting his RC tracked vehicle to take advantage of these perks using little more than 3D printed parts and aluminum stock.

This vehicle doesn’t just include the 3D printed tracks, but an entire 3D printed gearbox and drivetrain to drive them. Each track is driven by its own DC motor coupled to a planetary gearbox to give each plenty of torque to operate in snow or mud. The gearbox is mated to a differential which currently shares a shaft, which means that steering is currently not possible. The original plan was to have each motor drive the tracks independently but a small mistake in the build meant that the shaft needed to be tied together. [Let’s Print] has several options to eventually include steering, including an articulating body or redesigning the drivetrain to be able to separate the shaft.

While this vehicle currently has no wheels in order to improve traction, [Let’s Print] does point out that a pair of wheels could complement this vehicle when he finished the back half of it since wheels have a major advantage over tracks when it comes to steering. A vehicle with both could have the advantages of both, so we’re interested to see where this build eventually goes.

Thanks to [Joonas] for the tip!

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3D Printed Molds For Casting Rose’s Metal

March 17, 2022 by 21 Comments

Have you ever played with Rose’s metal? It’s a fusible alloy of bismuth, lead, and tin with a low melting point of around 100 °C. Historically, it’s been used as a solder for cast iron railings and things, and as a malleable pipe filler material to prevent crimping while a pipe is bent.

[Ben Healey] has been playing around with Rose’s metal and some PETG printed molds, making everything from Star Wars Imperial credits to chess pieces to leather stamping tools. In the video after the break, [Ben] takes us through the process, beginning with mold-making from STLs — something he picked up from another YouTuber.

He recommends adding registration marks to multi-part molds in order to keep everything lined up, and adding a small recess in the seam for easy separation with a flat-head screwdriver. So far, the molds have held up to multiple pours, though [Ben] did print them rather thick and is glad he did.

As far as making liquid metal, [Ben] used a cast iron pot with a convenient pour spout, and a blowtorch. He added graphite powder to the molds in an effort to make them give up the goods more easily. To finish the pieces, [Ben] cut the flashing with tin snips and used sandpaper and a Dremel to smooth the edges. Copper plating didn’t work out, but [Ben] is going to try it again because he thinks he screwed something up in the process. He’s also going to try printing with TPU, which we were just about to recommend for its flexibility.

There are many ways to cast metal on the (relatively) cheap. Have you considered Kinetic Sand?

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Remoticon 2021 // Arsenijs Tears Apart Your Laptop

March 17, 2022 by 9 Comments

Hackaday’s own [Arsenijs Picugins] has been rather busy hacking old laptops apart and learning what can and cannot be easily reused, and presents for the 2021 Hackaday Remoticon, a heavily meme-loaded presentation with some very practical advice.

Full HD, IPS LCD display with touch support, reused with the help of a dedicated driver board

What parts inside a dead laptop are worth keeping? Aside from removable items like RAM stick and hard drives, the most obvious first target is the LCD panel. These are surprisingly easy to use, with driver boards available on the usual marketplaces, so long as you make sure to check the exact model number of your panel is supported.

Many components inside laptops are actually USB devices, things like touch screen controllers, webcams and the like are usually separate modules, which simply take power and USB. This makes sense, since laptops already have a fair amount of external USB connectivity, why not use it internally too? Other items are a bit trickier: trackpads seem to be either PS/2 or I2C and need a bit more hardware support. Digital microphones mostly talk I2S, which means some microcontroller coding.

Some items need a little more care, however, so maybe avoid older Dell batteries, with their ‘spicy pillow’ tendencies. As [Arsenijs] says, take them when they are ripe for the picking, but not too ripe. Batteries need a little care and feeding, make sure you’ve got some cell protection, if you pull raw cells! Charging electronics are always on the motherboard, so that’s something you’ll need to arrange yourself if you take a battery module, but it isn’t difficult, so long as you can find your way around SMBus protocol.

These batteries are too ripe. Leave them alone.

Older laptops were much more modular and some even designed for upgrade or modification, and this miniaturization-driven trend of shrinking everything — where a laptop now needs to be thin enough to shave with — is causing some manufacturers to move in a much more proprietary direction regarding hardware design.

This progression conflicts with our concerns of privacy, repairability and waste elimination, resulting in closed boxes filled with unrepairable, non-reusable black boxes. We think it’s time to take back some of the hardware, so three cheers to those taking upon themselves the task to reverse engineer and publish reusability information, and long may it be possible to continue.

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Doubled Up 3D Printer Upgrade Doubles The Fun

March 17, 2022 by 19 Comments

[Nathan] from Nathan Builds Robots on YouTube is no stranger to modding 3D printers, whether it’s a good idea or not, it’s just fun to find out sometimes. His latest escapade he calls the Double Ender (video, embedded below), where he not only doubles up the hotend, but the doubles up a few other bits too. The aim was to achieve dual material printing, with his specific goal to combine plain nylon and carbon fiber-loaded nylon in the same print, to get the best properties of both materials.

Perfects results on the first try!

Taking a stock Ender 3 v2, [Nathan] first installs a dual Z axis kit, doubling up the Z axis screw and associated stepper motors. Likely this was needed to compensate for the additional weight of subsequent mods. Since the stock Ender mainboard has only one Z axis port, the less obvious solution was to just install a second mainboard! By leveraging the immense hackability of the Klipper printer firmware/software stack,he was able to get this weird configuration to work.

Next the main part of the build; the Phaetus Tai Chi dual hot end installation. For some reason, initially, it was decided to combine the stock bowden injector/extruder with a direct drive second unit, which we guess keeps the reciprocating weight down a bit and does let you directly compare bowden and direct drive print results on the same machine. Anyway, the first dual material prints came out pretty good after a few (quickly glossed over) fails, and did work well enough that dual-nylon printing could now be an option. After switching the build to a dual direct-drive setup, [Nathan] found it easier to get the machine to switch filaments more reliably, which makes sense when you think about the impact of all that extra filament in the bowden tube.

[Nathan] clearly has been burned (haven’t we all?) possibly literally, by the curious habit of some Chinese suppliers, of randomly assigning power supply polarity to red/black wire pairs. The solution, somewhat belt-and-braces, was to simply make up custom power cables with an embedded rectifier. Well, we guess that’s one less thing to worry about, but do look away when those PSU hacks are being shown!

Multi-material or multi-color FDM printer options are plenty, here’s a cool way of using a servo to swing a pair of hotends to the same point, and we also saw a while back, a way of using a sprung-loaded rocker to flip the unused hotend up out the way when not needed.

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Owning A ShortWave Radio Is Once Again A Subversive Activity

March 17, 2022 by 147 Comments

An abiding memory for a teen fascinated by electronics and radio in the 1970s and 1980s is the proliferation of propaganda stations that covered the shortwave spectrum. Some of them were slightly surreal such as Albania’s Radio Tirana which would proudly inform 1980s Western Europe that every village in the country now possessed a telephone, but most stations were the more mainstream ideological gladiating of Voice of America and Radio Moscow.

It’s a long-gone era as the Cold War is a distant memory and citizens East and West get their info from the Internet, but perhaps there’s an echo of those times following the invasion of the Ukraine. With most external news agencies thrown out of Russia and their websites blocked, international broadcasters are launching new shortwave services to get the news through. Owning a shortwave radio in Russia may once again be a subversive activity. Let’s build one!

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Wireless Charging For Border Patrol Drones

March 17, 2022 by 43 Comments

It makes sense to use drones to patrol borders or perimeters. But there’s a problem. Drones have to carry batteries or fuel and mostly have a short operating time. A new paper from the University of Houston proposes a solution by recharging drones in flight using a novel wireless charging mechanism. What’s the cost? Another paper explores the economics of the approach.

The system relies on electric lines running along a border wall feeding wireless power transfer devices that allow the drone to recharge in flight. This is akin, we think, to an electric train that takes power from the third rail except, in this case, the power rail is wireless. Also, the drone would still have batteries to enable it to go off the rail as needed.

The paper mentions that the source power could be from wind or solar, but that’s not necessarily important and it also requires a storage battery in the system that you could omit if using conventional power. In addition, you’d think batteries and solar panels might be targets for theft in remote areas.

The paper mentions that another alternative is to simply have charging towers along the wall where drones land to recharge. This is easier, we think, but it does put the drone out of full operation status while charging. On the other hand, cheap drones could work in shifts to cover an area, so it seems like that might be a better solution than charging while flying.

What do you think? How would you make a long-duration drone? Fuel cells? In-flight battery swapping from a refueling drone? Laser power? Maybe a magnetic battery swap system where the drone swoops over a charger to drop off and pick up a fresh battery? Let us know what you would try or — even better — what you have done.

We’ve seen a drone pit stop robot already. Refueling drones have been done, too. But it does seem like something better is possible.

An Old Typewriter Speaks To The World

March 17, 2022 by 20 Comments

Typewriters are something which was once ubiquitous, yet which abruptly faded away and are now a rare sight. There was a period of a few years in which electric typewriters and computers existed side-by-side though, and it’s one of these which [Jonah Brüchert] has experimented with connecting to a computer for use as a printer or terminal.

The machine in question is a SIGMA SM 8200i typewriter, which is a rebadged version of the East German Erika S3004. It has an intriguing 26-pin connector on its side which provides access to a 1200 baud serial port. It uses its own character encoding dubbed “gdrascii”, for which there is a Python library that he could port to Rust. The result is a terminal in the old style, from the days when access to a computer was through a teletype  rather than a screen. All that’s missing is a punched tape reader at its side!

We’ve featured a lot of typewriters here over the ears, but this isn’t the first that has received a terminal conversion.