2026-02-25 20:00:06
One of the more promising 3D printing technologies that hasn’t quite yet had its spotlight is volumetric 3D printing. Researchers from the Department of Automation, Tsinghua University, have developed a new method that uses a high-speed periscope instead of rotating the printing volume — resulting in print times of less than one second.
Normal volumetric printing uses a rotating volume of photosensitive resin to print nearly any geometry desired. However, this method presents issues when printing at high speeds. If you rapidly rotate a liquid, it won’t exactly stay still. So why not rotate the projector itself? This change also allows the use of less viscous resins, which is particularly useful if you want to pump fluid around.
Why would you want to pump around liquid? Scalability of course! Printing in seconds while pumping the results into a collection vessel would allow for mass production more flexible than traditional ejection methods. The researchers manage to keep quality high with some fancy algorithmic correction, which allows for accuracy on the scale of μm.
While this technology still doesn’t find a common space among average hobbyists, this may soon change…especially with these mass manufacturing capabilities. For similar volumetric printing capabilities, check out xolography.
2026-02-25 17:00:00
The Yamaha DX7 is one of the most iconic synthesizers that emerged in the early 1980s, and is still very popular today. That said, with even the newest of these having left the factory back in 1989, the average DX7 can use a bit of tender love and care. In particular the battered DX7 that [Drygol] recently got handed to ‘just fix the PSU voltage switch’. As it turned out, this poor DX7 had a few more issues than just a busted voltage selector.
In addition to missing slider caps and a vanished key, the paint of the case also had clearly lost a fight with various hard surfaces in addition to a thick coating of unidentifiable dust and grime inside the synthesizer. Feeling a pang of sympathy, [Drygol] thus decided to give the old girl a complete restoration.
After taking the synthesizer apart for a good scrub-down, the parts were assessed for further damage. This turned out to include the plastic stubs on some keys to hold a spring for which a replacement was modelled and 3D printed, along with replacements for the missing slider caps.
Next the case was painted, with a brand new Yamaha DX7 vinyl logo rather than trying to fix up the old paint and logo. With the outside fixed up, the broken and dodgy controls, audio jacks and potentiometers were addressed, followed by the busted onboard battery, leaving just the original voltage selector. This one got replaced by an IEC 60320 C13 jack, with the transformer hardwired for 230 VAC input, out of convenience grounds.
We’re always excited when [Drygol] sends in another restoration project — from a glowing Amiga 500 to vacuum-formed keycap covers, they’re always remarkable displays of ingenuity.
2026-02-25 14:00:39
There are some clocks, mostly in or around international airports, which have multiple faces to show the time at various cities around the world. Taking more a forward-looking approach is [Chronova Engineering], who built a clock to display the time on four different planets: Earth, Mars, Jupiter, and Saturn.
The clock doesn’t have any hands, but it uses rotating dials to represent a top-down view of each planet from it’s north pole. The dials have degree markings to represent rotation relative to each planet’s prime meridian; for the gas giants, rotation is measured by the rotation of the planet’s core. Each dial’s center is made out of a circular stone tile with patterns similar to those seen on the planet; Earth, for example, is represented with sodalite. Three pointers mounted around the dial indicate the longitudes which are currently experiencing sunrise, noon, and sunset. The mechanism can be turned with a handle or a knob, and a mechanical counter keeps track of the number of Earth days that have passed.
[Chronova] machined most of the mechanism out of brass, with a few steel parts. It required only nine gears, including the two idler gears which were used to space out the dials and keep them rotating in the right direction. The gears were machined on a jeweler’s lathe, with the cutouts in the idler gears being made with a pantograph milling machine and a 3D printed pattern. This isn’t technically a clock, since there’s no timekeeping mechanism, but it does accurately represent relative motion.
Though they represent different things, this project is reminiscent of an orrery, which [Chronova Engineering] has previously built. For more detail about the difficulties of synchronizing time between celestial bodies, check out this article about establishing a lunar time standard.
2026-02-25 11:00:34
While you may have never heard of TAT-8, there is a good chance you sent some data through it. TAT-8 was the 8th transatlantic communications cable and the first transatlantic fiber-optic cable, carrying 560 Mbit/s on two fibers between Tuckerton, New Jersey, and, thanks to an underwater splitting device, Widemouth Bay, England, and Penmarch, France. Construction of the cable began in 1998. Later that year, the first call, made by [Issac Asimov] took place. The cable was retired in 2002. Now, Subsea Environmental Services is recovering the cable for recycling.
The 6,000 km cable was built by a consortium of companies including AT&T, France Télécom, and British Telecom. The 1.3 micron fiber used special optical repeaters about 40 km apart and cost about $335 million (just shy of a billion dollars today). Designers were optimistic, with some claiming the cable would end the need for future cables or, at least, that the cable would not reach capacity for ten years or more. In reality, the cable was saturated within 18 months. Turns out, the equivalent of 40,000 phone lines wasn’t enough.
In all fairness, the saturation might have been difficult to predict, but it may also have been hastened by the cable itself. In 1989, IBM funded a dedicated T1 link between CERN and Cornell University. Ten months later, [Tim Berners Lee] would use this link to demonstrate his new development: The World Wide Web.
According to Subsea Environmental Services, the cable still looked new after lying on the seabed for four decades. We’ve looked at the tech behind these undersea cables before. Not to mention the history behind the TAT cables.
2026-02-25 08:00:22
BMX bikes are a unique frame geometry, essentially forgoing all travel efficiency for maneuverability and sturdiness. For how much abuse these bikes are designed to take, these are all good tradeoffs. But it turns out that these bikes also have an exceptionally low center of gravity, which could make them useful for drag racing, provided they’re given a suitably large electric motor and a few minor frame modifications.
The project began as a fun weekend project for friends [Sam Barker] and [Tom Stanton]. They had a 20″ BMX wheel with a massive integrated hub motor that seemed to be begging to be put onto a BMX bike that they had on hand. After hooking up a 72V, 20Ah battery to it they were quickly zipping around the driveway, but the short wheelbase on the bike was bottlenecking its maximum performace because the bike would wheelie under high throttle. To solve that, they broke out the welder and extended frame, which kept the wheelies to a minimum and allowed them to take it out and drag race.
Another benefit to the extended frame is that the bike has room to store its battery now as well; before the frame extension it was strapped to the side of the frame under the rider in a non-ergonomic fashion. The duo also had to figure out a braking solution since the BMX didn’t come with its own brakes, but a loaner caliper from a penny farthing was found for some basic stopping abilities. We might assume this bike is not street legal on many public roads, but not every ebike operates in the same legal jurisdictions you might be the most familiar with.
2026-02-25 05:00:44
If you know about Peltier modules, a solid-state fridge seems like an easy project. Pump 12V into the module, include a heat sink and a fan. Then you are done, right? According to [Peltier Power], this is not the way to design things, but it is common enough to give these units a reputation for failing quickly.
The problem is that while it makes sense that an inefficient Peltier module needs more power to get more cooling. But the reality is in practical applications, many designs push the current up when it should be moving it down. The curve describes a parabola, and you can be on the high side or low side and still get the same result. But obviously, you don’t want to put in more current and get the same cooling that you could get with lower currents.
According to the video, the mistake people make is pushing to a stable point to reach a cool point, then increasing the current until the chamber cools further. However, maintaining the cool doesn’t have to require a higher current. Once cold, you can reduce the current to maintain temperature, so to get colder, you can just lower the current less instead of increasing it. Of course, that’s somewhat of a simplification. You have to account for other thermal design factors, but that’s the general idea.
He has noted this behavior in commercial units, but did find one brand that had the correct logic. He also has some tips on using these types of coolers.
Our favorite use for these modules has to be a cloud chamber. Naturally, we’ve seen a fair number of homebrew fridges.
