Rock Sphere Machine Produces Off The Charts Satisfaction

[Michigan Rocks] says he avoided making rock spheres for a long time on account of the time and cost he imagined was involved. Well, all that is in the past in light of the fabulous results from his self-built Rock Sphere Machine! Turns out that it’s neither costly to make such a machine, nor particularly time-consuming to create the spheres once things are dialed in. The video is a journey of the very first run of the machine, and it’s a great tour.

The resulting sphere? Super satisfying to hold and handle. The surface is beyond smooth, with an oil-like glossy shine that is utterly dry to the touch.

The basic concept — that of three cordless drills in tension — is adapted from existing designs, but the implementation is all his own. First a rough-cut rock is held between three diamond bits. The drills turn at 100 RPM while a simple water reservoir drips from above. After two hours, there’s a fair bit of slurry and the rock has definitely changed.

[Michigan Rocks] moves on to polishing, which uses the same setup but with progressively-finer grinding pads in place of the cutting bits. This part is also really clever, because the DIY polishing pads are great hacks in and of themselves. They’re made from little more than PVC pipe end caps with hex bolts as shafts. The end caps are filled with epoxy and topped with a slightly concave surface of hook-and-loop fastener. By doing this, he can cut up larger fuzzy-backed polishing pads and stick the pieces to his drill-mounted holders as needed, all the way down to 6000 grit. He shows everything about the pads at the 11:55 mark, and it’s an approach worth keeping in mind.

What is the end result like? See for yourself, but we think [Michigan Rocks] sums it up when he says “I wish you could feel this thing, it feels so smooth. It’s so satisfying to roll around in your hands. I’m so happy I made this machine. This is awesome.”

We’ve seen machines for making wooden spheres but this one makes fantastic use of repurposed stuff like inexpensive cordless drills, and the sort of wood structures anyone with access to hand tools can make.

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Why Diamond Transistors Are So Hard To Make

Many things about diamonds seem eternal, including the many engineering problems related to making them work as a silicon replacement in semiconductor technology. Yet much like a diamond exposed to a stream of oxygen-rich air and a roughly 750°C heat source, time will eventually erase all of them. As detailed in a recent [Asianometry] video, over the decades the challenges with creating diamond wafers and finding the right way to dope pure diamond have been slowly solved, even if some challenges still remain today.

Diamond is basically the exact opposite as silicon when it comes to suitability as a semiconductor material, with a large bandgap (5.5 eV vs the 1.2 of silicon), and excellent thermal conductivity characteristics. This means that diamond transistors are very reliable, albeit harder to switch, and heat produced during switching is rapidly carried away instead of risking a meltdown as with silicon semiconductors.

Unlike silicon, however, diamond is much harder to turn into wafers as you cannot simply melt graphite and draw perfectly crystallized diamond out of said molten puddle. The journey of getting to the state-of-the art soon-to-be-4″ wafers grown on iridium alongside the current mosaic method is a good indication of the complete pain in the neck that just this challenge already is.

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R2D2 Gets New Brains

While it is fun to get toys that look like your favorite science fiction props, it is less fun when the electronics in them don’t measure up to the physical design. [Steve Gibbs] took a Hasbro R2D2 toy robot and decided to give it a brain upgrade along with enhanced sensors. You can see a video of the robot doing its thing and some build details below.

In this case, the toy from Hasbro was not working at all, so [Steve] saved it from the dumpster. Instead of a repair, he decided to just gut it and rebuild it with modern electronics. The ultrasonic sensor on the forward toe is a dead giveaway.

The robot responds to voice commands better than the original and can play sound effects and clips from Star Wars. You can also control the robot with a phone app. The new or upgraded sensors include microphones, a PIR sensor, a photoresistor to sense light, a smoke and CO2 sensor, a computer vision camera, and, of course, the ultrasonic range finder.

Some motors and the original speaker are in use, but R2 now sports additional LEDs and servos. All the extras required some surgery on the plastic body. Instead of regular batteries, the ‘bot now uses a LiPo battery, so the old battery compartment was cut out to make more room.

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Inside Raiders Of The Lost Ark (Atari Style)

It’s a bit ironic that an Atari 2600 game based on Raiders of the Lost Ark — a movie about archaeology — is now the subject of its own archaeological expedition as [Dennis Debro] and [Halkun] spent time reverse-engineering the game. Luckily, they shared their findings, so you can enjoy it the same way you can visit a king’s tomb without having to discover it and dig for it. If you don’t remember the game, you might enjoy the demo from [Speedy Walkthroughs] in the video below.

If you are only used to modern software, you might think this is little more than someone dumping the program code and commenting it. However, on these old, limited systems, you have to really understand the actual architecture because there are so many things you have to manage that are specific to the hardware.

For example, the game has two 4K ROM banks that use a strange switching mechanism. The entire game is built around the NTSC television signal. Everything is oriented toward generating the 60 Hz frame rate. Game logic runs during the vertical blanking and over-scan sections to prevent strange visible artifacts due to software running.

This is a fascinating look inside game coding as it existed around 1982. Of course, you can also run everything using emulation. Usually, our reverse engineering is more hardware-related. But we do love these old games, too.

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Custom Clamshell Cyberdeck Shows Off Underlighting

Cyberdecks are great projects, and [Salim Benbouziyane]’s scratch-built CM Deck is a fantastic specimen. It’s a clamshell-style cyberdeck with custom split keyboard, trackpad, optional external WiFi antenna, and some slick underlighting thanks to a translucent bottom shell. There’s even a hidden feature that seems super handy for a cyberdeck: a special USB-C port that, when plugged in to another host (like another computer), lets the cyberdeck act as an external keyboard and trackpad for that downstream machine.

The CM Deck is built around the Raspberry Pi Compute Module 5, which necessitates a custom PCB but offers more design freedom.

Notably, the CM Deck is custom-built around the Raspberry Pi Compute Model 5. When we first peeped the CM5 the small size was striking, but of course that comes at the cost of having no connectors, supporting hardware, or heat management. That’s something [Salim] embraced because it meant being able to put connectors exactly where he wanted them, and not have to work around existing hardware. A custom PCB let him to lay out his cyberdeck with greater freedom, less wasted space, and ultimately integrate a custom-built keyboard (with RP2040 and QMK firmware).

Even the final enclosure is custom-made, with 3D printing being used to validate the design and PCBway providing finished plastic shells in addition to manufacturing the PCBs. [Salim] admits that doing so was an indulgence, but his delight at the quality of the translucent purple undercarriage is palpable.

[Salim]’s video (embedded below) is a deep dive into the whole design and build process, and it’s a great watch for anyone interested in the kind of work and decisions that go into making something like this. Experienced folks can expect to nod in sympathy when [Salim] highlights gotchas like doing CAD work based on the screen’s drawings, only to discover later that the physical unit doesn’t quite match.

The GitHub repository contains the design files for everything, so give it a browse if you’re interested. [Salim] is no stranger to clean builds, so take a moment to admire his CRT-style Raspberry Pi terminal as well.

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Hackaday Podcast Episode 357: BreezyBox, Antique Tech, And Defusing Killer Robots

In the latest episode of the Hackaday Podcast, editors Elliot Williams and Tom Nardi start things off by discussing the game of lunar hide-and-seek that has researchers searching for the lost Luna 9 probe, and drop a few hints about the upcoming Hackaday Europe conference. From there they’ll marvel over a miniature operating system for the ESP32, examine the re-use of iPad displays, and find out about homebrew software development for an obscure Nintendo handheld. You’ll also hear about a gorgeous RGB 14-segment display, a robot that plays chess, and a custom 3D printed turntable for all your rotational needs. The episode wraps up with a sobering look at the dangers of industrial robotics, and some fascinating experiments to determine if a decade-old roll of PLA filament is worth keeping or not.

Check out the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Download this episode in DRM-free MP3 on your ESP32 with BreezyBox for maximum enjoyment.

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MyMiniFactory Has Acquired Thingiverse Bringing Anti-AI Focus

One of the best parts of 3D printing is that you can freely download the plans for countless models from sites like Thingiverse, Printables, and others. Yet with the veritable flood of models on these sites you also want to have some level of quality. Here recent news pertaining to Thingiverse is probably rather joyful, as with the acquisition of Thingiverse by MyMiniFactory, it should remain one of the most friendly sites for sharing 3D printing models.

Although Thingiverse as a concept probably doesn’t need much introduction, it’s important here to acknowledge the tumultuous times that it has gone through since its launch in 2008 as part of MakerBot. Both were acquired by Stratasys in 2013, and this has led to ups and downs in the relationship with Thingiverse’s user base.

MyMiniFactory was launched in 2013 as a similar kind of 3D printing object-sharing platform as Thingiverse, while also offering crowdsourcing and paid model options. In the MyMiniFactory blog post it’s stated that these features will not be added to Thingiverse, and that nothing should change for Thingiverse users in this regard.

What does change is its joining of the ‘SoulCrafted‘ initiative, which is an initiative against machine-generated content, including so-called ‘AI slop’. There will be a live Q & A on February 17th during which the community can pitch their questions and ideas, along with a dedicated Thingiverse group.