The central solenoid taking shape in the ITER assembly hall.

What’s Sixty Feet Across And Superconducting?

April 22, 2025 by Tyler August 32 Comments

What’s sixty feet (18.29 meters for the rest of the world) across and superconducting? The International Thermonuclear Experimental Reactor (ITER), and probably not much else.

The last parts of the central solenoid assembly have finally made their way to France from the United States, making both a milestone in the slow development of the world’s largest tokamak, and a reminder that despite the current international turmoil, we really can work together, even if we can’t agree on the units to do it in.

A cutaway diagram of the ITER tokamak showing the central solenoid — The central solenoid is in the “doughnut hole” of the tokamak in this cutaway diagram. Image: US ITER.

The central solenoid is 4.13 m across (that’s 13′ 7″ for burger enthusiasts) sits at the hole of the “doughnut” of the toroidal reactor. It is made up of six modules, each weighing 110 t (the weight of 44 Ford F-150 pickup trucks), stacked to a total height of 59 ft (that’s 18 m, if you prefer). Four of the six modules have been installed on-site, and the other two will be in place by the end of this year.

Each module was produced ITER by US, using superconducting material produced by ITER Japan, before being shipped for installation at the main ITER site in France — all to build a reactor based on a design from the Soviet Union. It doesn’t get much more international than this!

This magnet is, well, central to the functioning of a tokamak. Indeed, the presence of a central solenoid is one of the defining features of this type, compared to other toroidal rectors (like the earlier stellarator or spheromak). The central solenoid provides a strong magnetic field (in ITER, 13.1 T) that is key to confining and stabilizing the plasma in a tokamak, and inducing the 15 MA current that keeps the plasma going.

When it is eventually finished (now scheduled for initial operations in 2035) ITER aims to produce 500 MW of thermal power from 50 MW of input heating power via a deuterium-tritium fusion reaction. You can follow all news about the project here.

While a tokamak isn’t likely something you can hack together in your back yard, there’s always the Farnsworth Fusor, which you can even built to fit on your desk.

Printed Perpetual Calendar Clock Contains Clever Cams

April 21, 2025 by Tyler August 9 Comments

At Hackaday, it is always clock time, and clock time is a great time to check in with [shiura], whose 3D Printed Perpetual Calendar Clock is now at Version 2. A 3D printed calendar clock, well, no big deal, right? Grab a few steppers, slap in an ESP32 to connect to a time server, and you’re good. That’s where most of us would probably go, but most of us aren’t [shiura], who has some real mechanical chops.

The front face of the perpetual calendar clock. — There’s also a 24-hour dial, because why not?

This clock isn’t all mechanical. It probably could be, but at its core it uses a commercial quartz movement — you know, the cheap ones that take a single double-A battery. The only restriction is that the length of the hour axis must be twelve millimeters or more. Aside from that, a few self-tapping screws and an M8 nut, everything else is fully 3D printed.

From that simple quartz movement, [shiura]’s clock tracks not only the day of the week, the month and date — even in Febuary, and even compensating for leap years. Except for the inevitable drift (and battery changes) you should not have to adjust this clock until March 2100, assuming both you and the 3D printed mechanism live that long. Version one actually did all this, too, but somehow we missed it; version two has some improvements to aesthetics and usability. Take a tour of the mechanism in the video after the break.

We’ve featured several of [shiura]’s innovative clocks before, from a hybrid mechanical-analog display, to a splitless flip-clock, and a fully analog hollow face clock. Of course [shiura] is hardly our only clock-making contributor, because it it always clock time at Hackaday. Continue reading “Printed Perpetual Calendar Clock Contains Clever Cams” →

Benchy, printed upside down on [Josh's] Core R-Theta printer.

Non-planar Slicing Is For The Birds

April 20, 2025 by Tyler August 13 Comments

When we say non-planar slicing is for the birds, we mean [Joshua Bird], who demonstrates the versatility of his new non-planar S4-Slicer by printing a Benchy upside down with the “Core R-Theta” printer we have featured here before.

A benchy model, upside down, with the path from the end of the prow to the printbed highlighted. — S4 slicer uses the path from any point (here, Benchy’s prow) as its basis…

This non-planar slicer is built into a Jupyter notebook, which follows a relatively simple algorithm to automatically generate non-planar toolpaths for any model. It does this by first generating a tetrahedral mesh of the model and then calculating the shortest possible path through the model from any given tetrahedron to the print bed. Even with non-planar printing, you need to print from the print-bed up (or out).

Quite a lot of math is done to use these paths to calculate a deformation mesh, and we’ll leave that to [Joshua] to explain in his video below. After applying the deformation, he slices the resulting mesh in Cura, before the G-code goes back to Jupyter to be re-transformed, restoring the shape of the original mesh.

… to generate deformed models for slicing, like this.

So yes, it is G-code bending as others have demonstrated before, but in a reproducible, streamlined, and straightforward workflow. Indeed, [Josh] credits much of the work to earlier work on the S^3-Slicer, which inspired much of the logic and the name behind his S4 slicer. (Not S4 as in “more than S^3” but S4 as a contraction of “Simplified S^3”). Once again, open source allows for incremental innovation.

It is admittedly a computationally intensive process, and [Joshua] uses a simplified model of Benchy for this demo. This seems exactly the sort of thing we’d like to burn compute power on, though.

This sort of non-planar 3D printing is an exciting frontier, one which we have covered before. We’ve seen techniques for non-planar infill, or even to print overhangs on unmodified Cartesian printers, but this is probably the first time we’ve seen Benchy given the non-planar treatment. You can try S4 slicer for yourself via GitHub, or just watch the non-planar magic in action after the break. Continue reading “Non-planar Slicing Is For The Birds” →

Two laptops, side by side, running Llama2 in DOS.

Will It Run Llama 2? Now DOS Can

April 19, 2025 by Tyler August 20 Comments

Will a 486 run Crysis? No, of course not. Will it run a large language model (LLM)? Given the huge buildout of compute power to do just that, many people would scoff at the very notion. But [Yeo Kheng Meng] is not many people.

He has set up various DOS computers to run a stripped down version of the Llama 2 LLM, originally from Meta. More specifically, [Yeo Kheng Meng] is implementing [Andreq Karpathy]’s Llama2.c library, which we have seen here before, running on Windows 98.

Llama2.c is a wonderful bit of programming that lets one inference a trained Llama2 model in only seven hundred lines of C. It it is seven hundred lines of modern C, however, so porting to DOS 6.22 and the outdated i386 architecture took some doing. [Yeo Kheng Meng] documents that work, and benchmarks a few retrocomputers. As painful as it may be to say — yes, a 486 or a Pentium 1 can now be counted as “retro”.

The models are not large, of course, with TinyStories-trained 260 kB model churning out a blistering 2.08 tokens per second on a generic 486 box. Newer machines can run larger models faster, of course. Ironically a Pentium M Thinkpad T24 (was that really 21 years ago?) is able to run a larger 110 Mb model faster than [Yeo Kheng Meng]’s modern Ryzen 5 desktop. Not because the Pentium M is going blazing fast, mind you, but because a memory allocation error prevented that model from running on the modern CPU. Slow and steady finishes the race, it seems.

This port will run on any 32-bit i386 hardware, which leaves the 16-bit regime as the next challenge. If one of you can get an Llama 2 hosted locally on an 286 or a 68000-based machine, then we may have to stop asking “Does it run DOOM?” and start asking “Will it run an LLM?”

Continue reading “Will It Run Llama 2? Now DOS Can” →

Robot Picks Fruit And Changes Light Bulbs With Measuring Tape

April 18, 2025 by Tyler August 9 Comments

How far can you stretch a measuring tape before it buckles? The answer probably depends more on the tape than the user, but it does show how sturdy the coiled spring steel rulers can be. [Gengzhi He et. al.] may have been playing that game in the lab at UC San Diego when they hit upon the idea for a new kind of low-cost robotic gripper.

An image of the GRIP-tape robot described in the article, showing the tape-loop fingers. — Four motors, four strips of measuring tape (doubled up)– one robot hand.

With the lovely backronym “GRIP-tape” — standing for Grasping and Rolling in Plane — you get a sense for what this effector can do. Its two “fingers” are each made of loops of doubled-up measuring tape bound together with what looks suspiciously like duck tape. With four motors total, the fingers can be lengthened or shortened by spooling the tape, allowing a reaching motion, pivot closer or further apart for grasping, and move-in-place like conveyor belts, rotating the object in their grasp.

The combination means it can reach out, grab a light bulb, and screw it into a socket. Or open and decant a jar of spices. Another video shows the gripper reaching out to pick a lemon, and gently twist it off the tree. It’s quite a performance for a device with such modest components.

At the moment, the gripper is controlled via remote; the researchers plan on adding sensors and AI autonomous control. Read all the details in the preprint, or check below the fold to watch the robot in action.

This is hardly the first time we’ve highlighted a grabby robot. We’ve seen belts, we’ve seen origami — but this is the first time we’ve seen a measuring tape. Have you seen a cool robot? Toss us a tip. We’d love to hear from you. Continue reading “Robot Picks Fruit And Changes Light Bulbs With Measuring Tape” →

An electron microscope image of the aluminum alloy from the study.

D20-shaped Quasicrystal Makes High-Strength Alloy Printable

April 18, 2025 by Tyler August 7 Comments

When is a crystal not a crystal? When it’s a quasi-crystal, a paradoxical form of metal recently found in some 3D printed metal alloys by [A.D. Iams et al] at the American National Institute for Standards and Technology (NIST).

As you might remember from chemistry class, crystals are made up of blocks of atoms (usually called ‘unit cells’) that fit together in perfect repetition — baring dislocations, cracks, impurities, or anything else that might throw off a theoretically perfect crystal structure. There are only so many ways to tessellate atoms in 3D space; 230 of them, to be precise. A quasicrystal isn’t any of them. Rather than repeat endlessly in 3D space, a quasicrystal never repeats perfectly, like a 3D dimensional Penrose tile. The discovery of quasicrystals dates back to the 1980s, and was awarded a noble prize in 2011.

Penrose tiling of thick and thin rhombi — Penrose tiling– the pattern never repeats perfectly. Quasicrystals do this in 3D. (Image by Inductiveload, Public Domain)

Quasicrystals aren’t exactly common in nature, so how does 3D printing come into this? Well, it turns out that, quite accidentally, a particular Aluminum-Zirconium alloy was forming small zones of quasicrystals (the black spots in the image above) when used in powder bed fusion printing. Other high strength-alloys tended to be very prone to cracking, to the point of unusability, and this Al-Zr alloy, discovered in 2017, was the first of its class.

You might imagine that the non-regular structure of a quasicrystal wouldn’t propagate cracks as easily as a regular crystal structure, and you would be right! The NIST researchers obviously wanted to investigate why the printable alloy had the properties it does. When their crystallographic analysis showed not only five-fold, but also three-fold and two-fold rotational symmetry when examined from different angles, the researchers realized they had a quasicrystal on their hands. The unit cell is in the form of a 20-sided icosahedron, providing the penrose-style tiling that keeps the alloy from cracking.

You might say the original team that developed the alloy rolled a nat-20 on their crafting skill. Now that we understand why it works, this research opens up the doors for other metallic quasi-crystals to be developed on purpose, in aluminum and perhaps other alloys.

We’ve written about 3D metal printers before, and highlighted a DIY-able plastic SLS kit, but the high-power powder-bed systems needed for aluminum aren’t often found in makerspaces. If you’re building one or know someone who is, be sure to let us know.

Budget Schlieren Imaging Setup Uses 3D Printing To Reveal The Unseen

April 17, 2025 by Tyler August 9 Comments

We’re suckers here for projects that let you see the unseeable, and [Ayden Wardell Aerospace] provides that on a budget with their $30 Schlieren Imaging Setup. The unseeable in question is differences in air density– or, more precisely, differences in the refractive index of the fluid the imaging set up makes use of, in this case air. Think of how you can see waves of “heat” on a warm day– that’s lower-density hot air refracting light as it rises. Schlieren photography takes advantage of this, allowing to analyze fluid flows– for example, the mach cones in a DIY rocket nozzle, which is what got [Ayden Wardell Aerospace] interested in the technique.

Shock diamonds from a homemade rocket nozzle imaged by this setup. — Examining exhaust makes this a useful tool for [Aerospace].

This is a ‘classic’ mirror-and-lamp Schlieren set up. You put the system you wish to film near the focal plane of a spherical mirror, and camera and light source out at twice the focal distance. Rays deflected by changes in refractive index miss the camera– usually one places a razor blade precisely to block them, but [Ayden] found that when using a smart phone that was unnecessary, which shocked this author.

While it is possible that [Ayden Wardell Aerospace] has technically constructed a shadowgraph, they claim that carefully positioning the smartphone allows the sharp edge of the case to replace the razor blade. A shadowgraph, which shows the second derivative of density, is a perfectly valid technique for flow visualization, and is superior to Schlieren photography in some circumstances– when looking at shock waves, for example.

Regardless, the great thing about this project is that [Ayden Wardell Aerospace] provides us with STLs for the mirror and smartphone mounting, as well as providing a BOM and a clear instructional video. Rather than arguing in the comments if this is “truly” Schlieren imaging, grab a mirror, extrude some filament, and test it for yourself!

There are many ways to do Schlieren images. We’ve highighted background-oriented techniques, and seen how to do it with a moiré pattern, or even a selfie stick. Still, this is the first time 3D printing has gotten involved and the build video below is quick and worth watching for those sweet, sweet Schlieren images. Continue reading “Budget Schlieren Imaging Setup Uses 3D Printing To Reveal The Unseen” →