Printed Perpetual Calendar Clock Contains Clever Cams

April 21, 2025 by Tyler August 10 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” →

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” →

Building A Sliding Tile Clock

March 31, 2025 by Lewin Day 8 Comments

Hackers like making clocks, and we like reporting on them around these parts. Particularly if they’ve got a creative mechanism that we haven’t seen before. This fine timepiece from [gooikerjh] fits the bill precisely—it’s a sliding tile clock!

The brains of the build is an Arduino Nano ESP32. No, that’s not a typo. It’s basically an ESP32 in a Nano-like form factor. It relies on its in-built WiFi hardware to connect to the internet and synchronize itself with time servers so that it’s always showing accurate time. The ESP32 is set up to control a set of four stepper motors with a ULN2003 IC, and they run the neat time display mechanism.

All the custom parts are 3D printed, and the sliding tile concept is simple enough. There are four digits that show the time. Each digit contains number tiles that slide into place as the digit rotates. To increment the digit by one, it simply needs to be rotated 180 degrees by the relevant stepper motor, and the next number tile will slide into place.

We love a good clock at Hackaday—the more mechanical, the better. If you’re cooking up your own nifty and enigmatic clocks at home, don’t hesitate to drop us a line!

A blue-gloved hand holds a glass plate with a small off-white rectangular prism approximately one quarter the area of a fingernail in cross-section.

AI Helps Researchers Discover New Structural Materials

February 27, 2025 by Navarre Bartz 18 Comments

Nanostructured metamaterials have shown a lot of promise in what they can do in the lab, but often have fatal stress concentration factors that limit their applications. Researchers have now found a strong, lightweight nanostructured carbon. [via BGR]

Using a multi-objective Bayesian optimization (MBO) algorithm trained on finite element analysis (FEA) datasets to identify the best candidate nanostructures, the researchers then brought the theoretical material to life with 2 photon polymerization (2PP) photolithography. The resulting “carbon nanolattices achieve the compressive strength of carbon steels (180–360 MPa) with the density of Styrofoam (125–215 kg m⁻³) which exceeds the specific strengths of equivalent low-density materials by over an order of magnitude.”

While you probably shouldn’t start getting investors for your space elevator startup just yet, lighter materials like this are promising for a lot of applications, most notably more conventional aviation where fuel (or energy) prices are a big constraint on operations. As with any lab results, more work is needed until we see this in the real world, but it is nice to know that superalloys and composites aren’t the end of the road for strong and lightweight materials.

We’ve seen AI help identify battery materials already and this seems to be one avenue where generative AI isn’t just about making embarrassing photos or making us less intelligent.

A blue and white, 3D printed rose sits on a black surface with a fuzzy tan background behind it.

Thermorphs: Self-Folding 3D Prints

February 27, 2025 by Navarre Bartz 3 Comments

Prints separating from the build plate or warping when you don’t want them to is a headache for the additive manufacturer. [CNC Kitchen] walks us through a technique to use that warping to our advantage.

Based on a paper by researchers at the Morphing Matter Lab at UC Berkeley, [CNC Kitchen] wanted to try making 3D printed objects that could self-assemble when placed in hot water. Similar to a bimetal strip that you find in simple thermostats, the technique takes advantage of the stresses baked into the print and how they can relax when reaching the glass transition temperature of the polymer. By printing joints with PLA and TPU layers, you can guide the deformation in the direction you wish, and further tune the amount of stress in the part by changing the print speed of different sections.

[CNC Kitchen] found that Hilbert curve infill slows the printer down sufficiently to create relatively stress-free sections of a print to create flat sections which is an improvement over the original researchers’ all TPU flat sections with respect to rigidity. We’ve covered how to reduce warping in 3D prints, but now we can use those techniques in reverse to design self-assembling structures. These parts, being thermoplastic, can also be heated, reformed, and then exhibit shape memory when placed back into hot water. It’s very experimental, but we’re curious to see what sort of practical or artistic projects could be unlocked with this technique.

We’ve seen a few other interesting techniques with folded objects like laser cutter origami, some flat-to-folded 3D prints that might be interesting to try with this technique, and also folded hybrid mechanisms made with laser cutting and 3D printing.

Continue reading “Thermorphs: Self-Folding 3D Prints” →

A guy's leg encased in a 3D printer showing a fresh printed tattoo

Do, Dare Or Don’t? Getting Inked By A 3D Printer

February 2, 2025 by Heidi Ulrich 19 Comments

This unusual tattoo hack by [Emily The Engineer] is not for the weak of heart, but let’s be frank: we kind of know her for that. And she gives out a warning, albeit at a good 10 minutes in, to not do this at home. What she’s about to do takes creativity and tech obsession to the next level: to transform a 3D printer into a functional tattoo machine. Therefore, [Emily] ingeniously modified one of her standard 3D printers to operate two-dimensionally, swapped its plastic extruder for a tattoo gun, and, yes, even managed to persuade a willing participant to try it out.

The entire process can be seen in [Emily]’s video below, which humorously yet meticulously documents the journey from Sharpie test runs to actually inking skin. Aside from a lot of tongue-in-cheek trial and error, this project requires a sheer amount of problem-solving. [Emily] employs firmware edits to bypass safety checks, and clever hardware adaptations to ensure smooth transitions between strokes. One impressive upgrade is the emergency solenoid system, a literal panic button to stop the machine mid-tattoo in case of trouble—a critical addition for something with needles involved!

This hack sits on the edge of DIY body modification, raising eyebrows and technical questions alike. If you missed the warning and are now frantically searching for tattoo removal options, know we’ve covered some (but you might be rightfully scared of automating that, too, at this point). If you haven’t lifted a finger while reading this, just do the safe thing: watch [Emily]’s video, and tinker about the subsequent purposes this discovery creates for 3D printing or tattoo art.

Continue reading “Do, Dare Or Don’t? Getting Inked By A 3D Printer” →

A dismantled drill on a cluttered workbench

Going Brushless: Salvaging A Dead Drill

January 29, 2025 by Heidi Ulrich 26 Comments

Let’s face it—seeing a good tool go to waste is heartbreaking. So when his cordless drill’s motor gave up after some unfortunate exposure to the elements, [Chaz] wasn’t about to bin it. Instead, he embarked on a brave journey to breathe new life into the machine by swapping its dying brushed motor for a sleek brushless upgrade.

Things got real as [Chaz] dismantled the drill, comparing its guts to a salvaged portable bandsaw motor. What looked like an easy swap soon became a true hacker’s challenge: incompatible gear systems, dodgy windings, and warped laminations. Not discouraged by that, he dreamed up a hybrid solution: 3D-printing a custom adapter to make the brushless motor fit snugly into the existing housing.

The trickiest part was designing a speed control mechanism for the brushless motor—an impressively solved puzzle. After some serious elbow grease and ingenuity, the franken-drill emerged better than ever. We’ve seen some brushless hacks before, and this is worth adding to the list. A great tool hack and successful way to save an old beloved drill. Go ahead and check out the video below!

Continue reading “Going Brushless: Salvaging A Dead Drill” →