A Rotary Dial The 3D Printed Way

March 11, 2026 by Jenny List 1 Comment

There’s a meme which may have a basis in truth, of a teenager left clueless when presented with a rotary telephone. The dial, in reality a mechanical pulse chain generator, was once ubiquitous enough that having one in your parts bin was anything but unusual. If you’re curious about their inner workings in 2026 though, you may be out of luck. Never fear though, because [Moeya 3D Designs] is here with a fully 3D printed version. It’s not as compact as the original, but it’s all there.

If you’re not put off by the anime-style Japanese voice over on the video below the break and you can enable subtitles for your language, you get the full explanation. There’s a ratchet and spring on the dial, which when released drives a gear train that ends in a cam that would operate a switch for the pulses. Another set of gears drives a very neatly designed centrifugal speed governor, and we see the effect immediately when it is removed. We’re not sure who will go for this project, but we surely like it.

There are two videos below the break, with the dial shown off in the first and the design process in the second. Meanwhile we’ve talked in the past about the networks behind the dials. Continue reading “A Rotary Dial The 3D Printed Way” →

Arduino’s New AI-Centric Board Is The VENTUNO Q

March 10, 2026 by Maya Posch 29 Comments

There have been many questions about what direction Arduino would take after being bought by Qualcomm. Now it would seem that we’re getting a clearer picture. Perhaps unsurprisingly the answer appears to be ‘AI’, with the new Arduino VENTUNO Q SBC being advertised as ‘democratizing AI’ in the Qualcomm press release, although it also references robotics.

This new board is based around the Dragonwing IQ-8275 SoC along with an STM32H5F5 MCU, making it somewhat of a beefier brother of the previously covered Arduino Uno Q, which also offers an SoC/MCU hybrid solution. On the product page we can see the overall specifications for this new board, where the release date is specified as ‘soon’.

Its IQ-8275 SoC is part of Qualcomm’s IQ8 series, with eight 2.35 GHz ARM cores and an Adreno 623 GPU, paired with 16 GB of LPDDR5. The Cortex M33-based STM32H5F5 MCU comes with its own 4 MB of Flash and 1.5 MB of RAM, all on a board that’s significantly larger than the Uno Q and isn’t crippled by a single USB-C port as SoC I/O.

Although clearly more aimed at industrial and automation applications than the solution-in-search-of-a-problem Uno Q board, it remains to be seen whether this board will catch on with Arduino fans, or whether Qualcomm’s goal is more to break into whole new markets under the Arduino brand.

NaCl Casting Technique Really Earns Its Salt

February 28, 2026 by Tyler August 18 Comments

Sodium Chloride has a melting point of 801 C (1,474 F), putting it comfortably between commonly-cast materials like aluminum and bronze. Which led to [Robinson Foundry] asking the question: can you cast salt like a metal? The answer, surprisingly, was yes!

[Robinson] tries casting the salt with two different methods: like it was glass, and like it was metal. In the glass-like casting, he packs a ceramic mold with salt and tosses it into an electric kiln, there to melt and very slowly cool. In metal-like casting, he just tosses salt into a crucible and melts it in the same beer-can kiln we saw when we featured his lost-pla casting a while back. The molten salt is poured very carefully into sand casting molds. If you’re familiar with the technique, you can skip to about 5:20 when he does the reveal.

As it turns out, the sand casting works out much better. While the glass-style casting in the electric kiln grew much larger crystals and so is more translucent, it’s also stuck completely inside the porous ceramic. Perhaps the ceramic would need glazed to pull off that technique?

On the other hand, the sand reacts with the salt in some way– molten salt isn’t exactly a noble gas, after all–to create a lovely gunmetal finish to the parts. They almost look like metal, though the brittleness gives away the game when he opens the mold to show a dagger in several pieces. For the decorative busts and megalodon teeth in the test, though, it is a great success.

Now, we’re not going to say this video came about because of high metal prices, or comment on what sort of trade policies might be driving up the price of metals like aluminum in the USA, but we do think this a great hack. While salt-based castings are obviously going to have very different physical properties than metal, for decorative work, it creates a lovely finish out of a material that’s cheap as dirt. Hopefully he comes back to the glass-style casting; we would not want to trust that black coating around food, and a salt crystal salt shaker sounds too good to pass up.

The only times we’ve seen molten salt around here is in nuclear reactors, and in homemade batteries, though that first one obviously wasn’t table salt.

Continue reading “NaCl Casting Technique Really Earns Its Salt” →

Easily Replaceable USB-C Port Spawned By EU Laws

February 26, 2026 by Lewin Day 132 Comments

The USB-C port has become a defacto connectivity standard for modern devices, largely supplanting the ugly mess of barrel jacks and micro USB connectors that once cursed us. While their reliability is good, they don’t last forever, and can be a pain to replace in most devices if they do fail. However, a new part from JAE Electronics could change that.

The problem with replacing USB connectors in most hardware is that they’re soldered in place. To swap them out, you have to master both desoldering and soldering leads of a rather fine pitch. It’s all rather messy. In the interest of satisfying the EU’s new Ecodesign for Sustainable Products Regulation (ESPR), JAE Electronics has developed a USB-C connector that’s easier to replace. Rather than being soldered in, the part is simply clamped down on to a printed circuit board with small screws. As the part is torqued down, small gold-plated contacts are compressed into pads on the PCB to make the necessary contact.

The connector is fully compatible with USB 4 version 2.0. (Don’t ask us how they number these things anymore.) It comes in single and dual connector versions, and is capable of USB PD EPR at up to 240 W (5A/48V). The part does have some drawbacks—namely, the footprint of the metal-shelled part is somewhat larger than most soldered USB C connectors. Whether this precludes its use is very much an application-specific matter for product engineers to decide.

In any case, if you find yourself designing hardware with heavily-used USB C ports, you might find this part useful. It’s not widely available yet, but some parts should be landing at Mouser in coming months. We’ve explored some of the ways USB-C connectors can be fouled and damaged before, too. Sound off with your opinions on this new part in the comments.

Continue reading “Easily Replaceable USB-C Port Spawned By EU Laws” →

Peltier Fridges Have Early Death

February 24, 2026 by Al Williams 20 Comments

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.

Continue reading “Peltier Fridges Have Early Death” →

Using 3D Printed Breadboards To Accommodate Wide Boards

February 17, 2026 by Maya Posch 36 Comments

Although off-the-shelf breadboards are plentiful and cheap, they almost always seem to use the same basic design. Although you can clumsily reassemble most of them by removing the voltage rail section and merging a few boards together, wouldn’t it be nice if you had a breadboard that you could stick e.g. one of those wide ESP32 development boards onto and still have plenty of holes to poke wires and component leads into? Cue [Ludwin]’s 3D printable breadboard design that adds a big hole where otherwise wasted contact holes would be.

The related Instructables article provides a visual overview of the rationale and the assembly process. Obviously only the plastic shell of the breadboard is printed, after which the standard metal contacts are inserted. These contacts can be ‘borrowed’ from commercial boards, or you can buy the contacts separately.

For the design files there is a GitHub repository, with breadboard designs that target the ESP32, Raspberry Pi Pico, and the Arduino Nano. An overview of the currently available board designs is found on the Hackaday.io project page, with the top image showing many of them. In addition to the single big space design there are also a few variations that seek to accommodate just about any component and usage, making it rather versatile.

Real-Time 3D Room Mapping With ESP32, VL53L5CX Sensor And IMU

February 14, 2026 by Maya Posch 14 Comments

ST’s VL53L5CX is a very small 8×8 grid ranging sensor that can perform distance measurements at a distance of up to 4 meters. [Henrique Ferrolho] demonstrated that this little sensor can also be used to perform a 3D scan of a room. The sensor data can be combined with an IMU to add orientation information to the scan data. These data streams are then combined by an ESP32 MCU that streams the data as JSON to a connected computer.

Of course, that’s just the heavily abbreviated version, with the video covering the many implementation details that crop up when implementing the system, including noise filtering, orientation tracking using the IMU and a variety of plane fitting algorithms to consider.

Note that ST produces a range of these Time-of-Flight sensors that are more basic, such as the VL53VL0X, which is a simple distance meter limited to 2 meters. The VL53L5CX features the multizone array, 4-meter distance range, and 60 Hz sampling speed features that make it significantly more useful for this 3D scanning purpose.

Continue reading “Real-Time 3D Room Mapping With ESP32, VL53L5CX Sensor And IMU” →