A LEGO Orrery

We aren’t sure how accurate you can get with LEGO, but a building block orrery looks cool, if nothing else. [Marian42] saw one done a few years ago and decided to build a version with a different mechanism. At first, the plan was to use some 3D printed fixtures, but the final product is made entirely from LEGO bricks. Very impressive. The video below shows that it has been complete for awhile, but the write-up that goes into great detail has only just arrived and it was worth the wait.

This is one of those things that seems simple if you don’t think too hard about it. However, when you sit down to actually do it, there are a number of challenges. For one thing, the Earth tilts at 23.5 degrees, and as the planet rotates, the tilt stays in the same direction, making it tricky to model mechanically.

The moon also has a 5.15 degree inclination, but since that’s hard to notice at this scale, the LEGO orrery exaggerates it. So, the Moon’s track has its own set of design problems. The whole thing has to rotate on a concentric shaft, which is also tricky to get right with kids’ building blocks.

Compared to the last orrery we saw, this one is huge. We’ve always been partial to ones that you have to look up to.

Continue reading “A LEGO Orrery”

Hackaday Links Column Banner

Hackaday Links: June 9, 2024

We’ve been harping a lot lately about the effort by carmakers to kill off AM radio, ostensibly because making EVs that don’t emit enough electromagnetic interference to swamp broadcast signals is a practical impossibility. In the US, push-back from lawmakers — no doubt spurred by radio industry lobbyists — has put the brakes on the move a bit, on the understandable grounds that an entire emergency communication system largely centered around AM radio has been in place for the last seven decades or so. Not so in Japan, though, as thirteen of the nation’s 47 broadcasters have voluntarily shut down their AM transmitters in what’s billed as an “impact study” by the Ministry of Internal Affairs and Communications. The request for the study actually came from the broadcasters, with one being quoted in a hearing on the matter as “hop[ing] that AM broadcasting will be promptly discontinued.” So the writing is apparently on the wall for AM radio in Japan.

Continue reading “Hackaday Links: June 9, 2024”

Making Intel Mad, Retrocomputing Edition

Intel has had a deathgrip on the PC world since the standardization around the software and hardware available on IBM boxes in the 90s. And if you think you’re free of them because you have an AMD chip, that’s just Intel’s instruction set with a different badge on the silicon. At least AMD licenses it, though — in the 80s there was another game in town that didn’t exactly ask for permission before implementing, and improving upon, the Intel chips available at the time.

The NEC V20 CPU was a chip that was a drop-in replacement for the Intel 8088 and made some performance improvements to it as well. Even though the 186 and 286 were available at the time of its release, this was an era before planned obsolescence as a business model was king so there were plenty of 8088 systems still working and relevant that could take advantage of this upgrade. In fact, the V20 was able to implement some of the improved instructions from these more modern chips. And this wasn’t an expensive upgrade either, with kits starting around $16 at the time which is about $50 today, adjusting for inflation.

This deep dive into the V20 isn’t limited to a history lesson and technological discussion, though. There’s also a project based on Arduino which makes use of the 8088 with some upgrades to support the NEC V20 and a test suite for a V20 emulator as well.

If you had an original IBM with one of these chips, though, things weren’t all smooth sailing for this straightforward upgrade at the time. A years-long legal battle ensued over the contents of the V20 microcode and whether or not it constituted copyright infringement. Intel was able to drag the process out long enough that by the time the lawsuit settled, the chips were relatively obsolete, leaving the NEC V20 to sit firmly in retrocomputing (and legal) history.

Can A Toy Printer Be Made Great?

Now that the bottom end of the 3D printer market has been largely cleared of those garbage “Prusa i3 clone” models which used to infest it a few years ago, a new breed of ultra-cheap printer has taken their place. EasyThreed make a range of very small printers pitched as toys, and while they’re no great shakes by the standards of most Hackaday readers, they do at least work out of the box. For their roughly $75 price tag they deliver what you’d expect, but can such a basic machine be improved with a few upgrades? [Made with Layers] has taken a look.

These printers have an all-plastic snap-together construction with a 10 cm by 10 cm bed and a set of small geared stepper motors driving their axes. He concentrates on stiffening the structure, upgrading those motors, and because he’s sponsored by a 3D printer electronics company, upgrading their controller.

The motors were replaced first with some NEMA 11 steppers, and then by some over-sized ones which maybe push the idea a little far. By moving the motors to a bracket he was able to free up their mountings to secure a 3D printed insert to stiffen the arms. Perhaps he’s pushing it a little for the video with the electronics upgrade, but we think there’s a happy medium with the smaller of the two motor upgrades and the stiffening.

So if you have an EasyThreed in your life it’s possible to upgrade it into something a little better, but it’s worth asking whether that $75 might be better spent in saving for a better machine in the first place. We’ve been curious about these tiny printers for a while though, and it’s interesting to have some more of our questions answered.

Continue reading “Can A Toy Printer Be Made Great?”

A Wireless Monitor Without Breaking The Bank

The quality of available video production equipment has increased hugely as digital video and then high-definition equipment have entered the market. But there are still some components which are expensive, one of which is a decent quality HD wireless monitor. Along comes [FuzzyLogic] with a solution, in the form of an external monitor for a laptop, driven by a wireless HDMI extender.

In one sense this project involves plugging in a series of components and simply using them for their intended purpose, however it’s more than that in that it involves some rather useful 3D printed parts to make a truly portable wireless monitor, as well as saving the rest of us the gamble of buying wireless HDMI extender without knowing whether it would deliver.

He initially tried an HDMI-to-USB dongle and a streaming Raspberry Pi, however the latency was far too high to be useful. The extender does have a small delay, but not so bad as to be unusable. The whole including the monitor can be powered from a large USB power bank, answering one of our questions. All the files can be downloaded from Printables should you wish to follow the same path, and meanwhile there’s a video with the details below the break.

Continue reading “A Wireless Monitor Without Breaking The Bank”

A Compact Electrohydrodynamic Pump Using Copper And TPU

Electrohydrodynamics (EHD) involves the dynamics of electrically charged fluids, which effectively means making fluids move using nothing but electric fields, making it an attractive idea for creating a pump out of. This is the topic of a 2023 paper by [Michael Smith] and colleagues in Science, titled “Fiber pumps for wearable fluidic systems”. The ‘fiber pumps’ as they call the EHD pumps in this study are manufactured by twisting two helical, 80 µm thick copper electrodes around a central mandrel, along with TPU (thermoplastic polyurethane) before applying heat. This creates a tube where the two continuous electrodes are in contact with any fluids inside the tube.

For the fluid a dielectric fluid is required to create the ions, which was 3M Novec 7100, a methoxy-fluorocarbon. Because of the used voltage of 8 kV, a high electrical breakdown of the fluid is required. After ionization the required current is relatively low, with power usage reported as 0.9 W/m, with one meter of this pump generating a pressure of up to 100 kilopascals and a flowrate of 55 mL/minute. One major limitation is still that after 6 days of continuous pumping, the copper electrodes are rendered inert due to deposits, requiring the entire system to be rinsed. Among the applications the researchers see artificial muscles and flexible tubing in clothing to cool, heat and provide sensory feedback in VR applications.

While the lack of moving parts as with traditional pumps is nice, the limitations are still pretty severe. What is however interesting about this manufacturing method is that it is available to just about any hobbyist who happens to have some copper wiring, TPU filament and something that could serve as a mandrel lying around.

Thanks to [Aaron Eiche] for the tip.

What If The Matrix Was Made In The 1950s?

We’ve noticed a recent YouTube trend of producing trailers for shows and movies as if they were produced in the 1950s, even when they weren’t. The results are impressive and, as you might expect, leverage AI generation tools. While we enjoy watching them, we were especially interested in [Patrick Gibney’s] peek behind the curtain of how he makes them, as you can see below. If you want to see an example of the result first, check out the second video, showing a 1950s-era The Matrix.

Of course, you could do some of it yourself, but if you want the full AI experience, [Patrick] suggests using ChatGPT to produce a script, though he admits that if he did that, he would tweak the results. Other AI tools create the pictures used and the announcer-style narration. Another tool produces cinematographic shots that include the motion of the “actors” and other things in the scene. More tools create the background music.

Continue reading “What If The Matrix Was Made In The 1950s?”