Making Optical Glass From Ceran Stovetops

June 28, 2025 by Maya Posch 2 Comments

The Ceran discs, freshly cut from the old stovetop and awaiting polishing. (Credit: Huygens Optics)

Ceran is a name brand for a type of glass ceramic that has a very low coefficient of thermal expansion (CTE). This is useful for stovetops, but it is also a highly desirable property for optical glass. The natural question: Can an old ceramic stovetop be upcycled into something visually striking? This is the topic of the most recent video in [Huygens Optics]’s series on glass ceramics.

Interestingly, by baking sections of the Ceran glass ceramic for 10 minutes at 961 °C, the CTE can be lowered by another five times, from 0.5 ppm / °C to a mere 0.1 ppm / °C. Following baking, you need a lot of grinding and polishing to remove any warping, existing textures, and printing. After polishing with 220 grit by hand for a few minutes, most of these issues were fixed, but for subsequent polishing, you want to use a machine to get the required nanometer-level precision, as well as to survive the six to eight hours of polishing.

Following this final polishing, the discs were ground into mirrors for a Newtonian telescope. This raised a small issue of the Ceran being only 4 mm thick, which requires doubling up two of the discs using a very thin layer of epoxy. After careful drilling, dodging cracked glass, and more polishing, this produced the world’s first ceramic stovetop upcycled into a telescope. We think it was the first, anyway. All that’s left is to coat the discs with a more reflective coating and install them into a telescope frame, but even in their raw state, they show the potential of this kind of material.

If you decide to try this, and you’ve already cut up your stove, you might as well attack some kitchen bowls, too.

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BeyBlades Made Ever More Dangerous With 3D Printing

June 28, 2025 by Lewin Day 11 Comments

If you’re unfamiliar with Beyblades, they’re a simple toy. They consist of spinning tops, which are designed to “fight” in arenas by knocking each other around. While the off-the-shelf models are deemed safe enough for children to play with, [Jon Bringus] decided to take the danger level up a few notches with some custom launchers of his own design.

[Jon]’s project started with some of the early metal Beyblades, which are traditionally launched with a small geared ripcord device. He soon realized he could up the action by doing one simple thing—spinning the tops far faster than the manufacturer ever intended. More rotational speed equals more kinetic energy equals more ~~legal liability~~ fun, or so the equation goes.

The design for [Jon’s] “WMD Launcher” is straightforward enough—he combined a lawnmower pull starter with a 12:1 geartrain to turn the Beyblades at truly ludicrous speeds. It’s basic engineering — a couple of 3D-printed gears do the job — but the results are hilarious. The tops begin to emit loud noises as they turn in combat, and some move so fast and erratically that they won’t even stay inside the arena. Protective eyewear is virtually mandatory. Files are on Printables for those eager to build one at home.

Yes, ruining a game of Beyblades is as simple as building an irresponsibly fast launcher. You needn’t even use some fancy brushless motor to hurt yourself — just a little gearing is enough to cause havoc. We’ve featured similar work on this topic before, too. Video after the break.

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Limitations, Creativity, And Challenges

June 28, 2025 by Elliot Williams 6 Comments

This week, we announced the winners for the previous Pet Hacks contest and rang in our new contest: The One Hertz Challenge. So that’s got me in a contesty mood, and I thought I’d share a little bit of soap-box philosophizing and inside baseball all at once.

The trick to creating a good contest theme, at least for the creative Hackaday crowd, is putting on the right limitation. Maybe you have to fit the circuit within a square-inch, power it only with a coin cell, or use the antiquated and nearly useless 555 timer IC. (Yes, that was a joke!)

There are two basic reactions when you try to constrain a hacker. Some instantly try to break out of the constraint, and their minds starts to fly in all of the directions that lead out of the box, and oftentimes, something cool comes out of it. The other type accepts the constraint and dives in deep to work within it, meditating deeply on all the possibilities that lie within the 555.

Of course, we try to accommodate both modes, and the jury is still out as to which ends up better in the end. For the Coin Cell challenge, for instance, we had a coin-cell-powered spot welder and car jumpstarter, but we also had some cool circuits that would run nearly forever on a single battery; working against and with the constraints.

Which type of hacker are you? (And while we’re still in the mood, what contest themes would you like to see for 2026?)

Behind The Bally Home Computer System

June 28, 2025 by Bryan Cockfield 9 Comments

Although we might all fundamentally recognize that gaming consoles are just specialized computers, we generally treat them, culturally and physically, differently than we do desktops or laptops. But there was a time in the not-too-distant past where the line between home computer and video game console was a lot more blurred than it is today. Even before Microsoft entered the scene, companies like Atari and Commodore were building both types of computer, often with overlapping hardware and capabilities. But they weren’t the only games in town. This video takes a look at the Bally Home Computer System, which was a predecessor of many of the more recognized computers and gaming systems of the 80s.

At the time, Bally as a company was much more widely known in the pinball industry, but they seemed to have a bit of foresight that the computers used in arcades would eventually transition to the home in some way. The premise of this console was to essentially start out as a video game system that could expand into a much more full-featured computer with add-ons. In addition to game cartridges it came with a BASIC interpreter cartridge which could be used for programming. It was also based on the Z80 microprocessor which was used in other popular PCs of the time, so in theory it could have been a commercial success but it was never able to find itself at the top of the PC pack.

Although it maintains a bit of a cult following, it’s a limited system even by the standards of the day, as the video’s creator [Vintage Geek] demonstrates. The controllers are fairly cumbersome, and programming in BASIC is extremely tedious without a full keyboard available. But it did make clever use of the technology at the time even if it was never a commercial success. Its graphics capabilities were ahead of other competing systems and would inspire subsequent designs in later systems. It’s also not the last time that a video game system that was a commercial failure would develop a following lasting far longer than anyone would have predicted.

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A Wood Chipper From First Principles

June 28, 2025 by Bryan Cockfield 10 Comments

For whatever reason, certain pieces of technology can have a difficult time interacting with the physical world. Anyone who has ever used a printer or copier can attest to this, as can anyone whose robot vacuum failed to detect certain types of non-vacuumable waste in their path, making a simple problem much worse. Farm equipment often falls into this category as well, where often complex machinery needs an inordinate amount of maintenance and repair just to operate normally. Wood chippers specifically seem to always get jammed or not work at all, so [Homemade Inventions] took a shot at building one on their own.

To build this screw-based wood chipper, the first thing to fabricate is the screw mechanism itself. A number of circles of thick steel were cut out and then shaped into pieces resembling large lock washers. These were then installed on a shaft and welded end-to-end, creating the helical screw mechanism. With the “threads” of the screw sharpened it is placed into a cylinder with a port cut out to feed the wood into. Powering the screw is a 3 kW electric motor paired with a custom 7:1 gearbox, spinning the screw at around 200 rpm. With that, [Homemade Inventions] has been able to easily chip branches up to 5 centimeters thick, and theorizes that it could chip branches even thicker than that.

Of course, wood chippers are among the more dangerous tools that are easily available to anyone with enough money to buy one or enough skill to build one, along with chainsaws, angle grinders, and table saws, so make sure to take appropriate safety precautions when using or building any of these things. Of course, knowing the dangers of these tools have led to people attempting to make safer versions like this self-propelled chainsaw mill or the semi-controversial table saw safety standard.

Thanks to [Keith] for the tip!

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Building A 3D-Printed RC Dump Truck

June 27, 2025 by Lewin Day 1 Comment

Whatever your day job, many of us would love to jump behind the controls of a dump truck for a lark. In the real world, that takes training and expertise and the opportunity is denied to many of us. However, you can live out those dreams on your desk with this 3D-printed build from [ProfessorBoots.]

The build exists as two separate parts—the tractor, and the trailer. The tractor is effectively a fairly straightforward custom RC build, albeit with a few additional features to make it fit for purpose. It’s got six wheels as befitting a proper semi, and it has a nifty retractable magnetic hitch mechanism. This lets it hook up to various trailers and unhitch from them as desired, all from a press on the remote. The hitch also has provision for power and control lines that control whatever trailer happens to be attached.

As for the trailer, it’s a side-dumper that can drop its load to the left or right as desired. The dumping is controlled via a linear actuator using a small DC motor and a threaded rod. A servo controls a sliding locking mechanism which determines whether the truck dumps to the left or right as the linear actuator rises up.

The design video covers the 3D printed design as well as some great action shots of the dump truck doing its thing. We’ve featured some builds from [ProfessorBoots] before, too, like this neat 3D-printed forklift . Video after the break.

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All The Stars, All The Time

June 27, 2025 by Bryan Cockfield 5 Comments

Some of the largest objects in the night sky to view through a telescope are galaxies and supernova remnants, often many times larger in size than the moon but generally much less bright. Even so, they take up a mere fraction of the night sky, with even the largest planets in our solar system only taking up a few arcseconds and stars appearing as point sources. There are more things to look at in the sky than there are telescopes, regardless of size, so it might almost seem like an impossible task to see everything. Yet that’s what this new telescope in Chile aims to do.

The Vera C. Rubin Observatory plans to image the entire sky every few nights over a period lasting for ten years. This will allow astronomers to see the many ways the cosmos change with more data than has ever been available to them. The field of view of the telescope is about 3.5 degrees in diameter, so it needs to move often and quickly in order to take these images. At first glance the telescope looks like any other large, visible light telescope on the tops of the Andes, Mauna Kea, or the Canary Islands. But it has a huge motor to move it, as well as a large sensor which generates a 3200-megapixel image every 30 seconds.

In many ways the observatory’s telescope an imaging technology is only the first part of the project. A number of machine learning algorithms and other software solutions have been created to help astronomers sift through the huge amount of data the telescope is generating and find new irregularities in the data, from asteroids to supernovae. First light for the telescope was this month, June 2025, and some of the first images can be seen here. There have been a number of interesting astronomical observations underway lately even excluding the JWST. Take a look at this solar telescope which uses a new algorithm to take much higher resolution images than ever before.