A DIY 3D Printing Filament Dryer

May 20, 2026 by 17 Comments

In a recent video [Saša Karanović] revisits the DIY filament dryer that he gave a shot a couple of years ago. Back then he reused an existing filament dryer, adding a custom controller and such to improve its performance. This technically-not-fully-DIY dryer got some feedback since then, and thus the V2 version is an example of how to better DIY such a dryer, including a custom PCB and a GitHub project for all the details.

Those who just want to dive into the documentation for assembly and the BOM can look at the available documentation. At its core the whole assembly consists of some kind of container like the shown 5L food storage type, along with an SHT30 temperature and humidity sensor and 100K NTC temperature sensor. These connect to the controller board which then switches on or off the 12V polymide resistive heater.

One thing that could be improved here is that the saturated warm air has nowhere to go. This is a common issue with filament dryers and why it’s recommended with even commercial filament dryers like the common Sunlu types to leave them slightly ajar so that the moist air can be replaced with cooler air that can much more readily absorb moisture.

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Two printed circuit boards made from 3D prints and copper foil. One white and one black substrate.

Using 3D Printers To Make Circuit Boards

May 19, 2026 by 49 Comments

Custom printed circuit boards have become more and more accessible to the average hobbyist over the last decade. But one problem still remains: your circuits will take at least a couple days to make. But what if you needed some really rapid prototypes? [The Raccoon Lab] shows us how to do it with a 3D printer.

You start with the usual hobby PCB pipeline: take your idea, make a schematic, and then lay it out in KiCad. That’s where the changes start: to keep traces strong, they are made very thick. The PCB is then exported and opened in 3D CAD software, where the traces are extruded to be 2 mm tall. Off to the printer! The newly printed “circuit board” is made conductive by applying copper tape to it, and traces are cut out along their raised edges.

The result is a very quick and dirty PCB. Sure, it isn’t exactly production-ready, but for just about any simple microcontroller project it’ll do just fine, and it’s a whole lot more accessible than milling one using a CNC! We’ve seen a few variations on this approach recently, including some custom software designed to help along the process.
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Electroplating 3D Prints Without Requiring A Big Vat

May 18, 2026 by 21 Comments

Electroplating 3D prints is a good way to get a pretty nice coating on even a basic PLA part, but generally you’re expected to dunk the entire part into a big vat with electrolyte after coating it with the requisite conductive paint layer. This is great for small parts, like a ring you’d put on a finger, but gets rather silly when it’s a much larger part, such as the one in [Hendrik]’s recent video. Out of curiosity he tried to see whether rotating the part through a much smaller vat would still get you an even coating, or not.

Perhaps ironically this process required building a custom vat out of acrylic, as well as an entire rig to hold up the part and gently rotate it. This highlights the main disadvantage of this approach, in that unless you’re doing a small production run or otherwise get to re-use the rig a lot it’s a lot of extra effort.

That said, the rotation is controlled by an ESP32 and a stepper motor along with a requisite stepper driver, with the most exotic part being the whole custom PCB and enclosure, all of which can be used repeatedly. With all of that tested and confirmed working, the part to be plated was sanded, sprayed with conductive paint and hooked up to the rotating rig for an overnight run.

Following that the part’s new copper coating was polished before more layers of electroplating were applied to get the desired two different colors from different metals. Along the way no issues were found with this method of rotating electroplating, so if you regularly struggle with oversized parts to electroplate, this would seem to be a viable method.

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A black screen with green text is shown. The green text logs events from a VPN gateway.

Running A VPN Gateway On An ESP32

May 18, 2026 by 23 Comments

If you need a VPN gateway to access your home network, the fastest and most cost-effective way is probably by using a Raspberry Pi Zero. But in [Samir Makwana]’s view, an ESP32-S3 is just as capable for moderate use, and in some respects even superior.

This was possible thanks to the MicroLink project, which is a full implementation of a Tailscale client for the ESP32 family. In some ways the ESP32 worked better than a Raspberry Pi: it boots in two seconds rather than thirty, draws 0.5 Watts rather than 1.5, and there’s no chance of it failing due to a corrupted SD card. Compared to a Raspberry Pi, however, which can be set up as a Tailscale client in a few minutes, this took several hours to get running. The biggest issue was making sure that there was enough memory available for TLS handshakes, which was solved by enabling the ESP32’s PSRAM.

Once the VPN client is running, the ESP32 can be used as an SSH jump machine to access other devices on the home network, without needing to expose those machines to the open Internet. The ESP32 also hosts an HTTP server which can send a wake-on-LAN magic packet to another device on the local network, letting unused devices sleep without impairing their availability.

The ESP32 doesn’t provide much bandwidth — streaming video would cause issues — but it works well enough for lightweight applications. If you’re wanting to stream video from an ESP32, though, it is technically possible.

Qualcomm’s New QCC74x Appears To Target The ESP32 MCUs

May 17, 2026 by 38 Comments

These days wireless microcontrollers featuring built-in WiFi and Bluetooth are all the rage, with Espressif’s range of ESP32 MCUs being the default option for commercial and hobbyist projects alike. This makes Qualcomm’s recently released QCC74x MCU rather interesting, as specification-wise it would seem to be placed firmly in ESP32 territory.

On the radio side you get 1×1 WiFi 6, Bluetooth 5.4, and IEEE 802.15.4 (e.g. Thread and Zigbee), coupled with a single-core 352 MHz RISC-V CPU with FPU and DSP features and 484 kB of SRAM. The SDK for this MCU is hosted on Codelinaro, featuring the typical FreeRTOS-based stack, though confusingly Bluetooth and Zigbee support are currently marked as ‘not supported’. This might still be in progress.

Where the competition with Espressif feels clear is in the pricing, with the highest-performance evaluation board (QCC748M EVK, pictured above) listed for $13 (before taxes/tariffs). This gets you 8 MB of PSRAM built-in with unspecified link speed, but likely the same QSPI as used for the NOR Flash. USB support is available on this higher-end tier, while absent on the QCC743. Development documentation is also available, and looks fairly complete based on first glance.

Overall the QCC74x looks to be an upgrade to the older and significantly less powerful QCC730 MCU. Depending on software support and final pricing it could make for an interesting competitor to some of Espressif’s modules like its ESP32-C series or ESP32-S2, though the upcoming ESP32-S31 would seem to have it matched or beat on all metrics.

Extract 3D Video Game Content By Firing Up Photo Mode

May 17, 2026 by 10 Comments

Here’s a pretty clever method [Dung3onlord] used to capture 3D scenes from a PlayStation 5 without needing any specialized software. All that’s needed is a series of high-resolution screenshots, and a few software tools.

The process is essentially photogrammetry, it just uses screenshots as the input instead of photographs.

Instead of sneakily yanking 3D assets from the runtime, he fires up the game’s photo mode on his PS5. By capturing an orbiting video of a static scene (making sure to hide the game’s user interface, something photo mode in games is good for) he ends up with a video file whose content — essentially a series of screenshots — can be used to reconstruct the original 3D scene. The workflow [Dung3onlord] uses has rather more steps, but conceptually that’s all there is to it.

The whole process is remarkably similar to photogrammetry, a method of turning a bunch of photographs from different angles into a 3D point cloud. We’ve seen photogrammetry used to digitize objects because point clouds can be turned into 3D models, essentially allowing one to 3D scan an object using little more than a digital camera.

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What a punch card looks like to openCV

21st Century Punch Cards Are 3D Printed And Read By OpenCV

May 16, 2026 by 14 Comments

While a punch card is perhaps the lowest-density storage medium available, it has some distinct advantages. As [Bitroller] points out in the write-up of his punch card project, if he was using stainless steel instead of PLA his 3D printed punch cards would likely outlast everything he owns, and survive a five-alarm fire to boot. If you have 16 bytes you really, really don’t want to forget — or are willing to store your private key in a shoe box — this project might be of interest.

The nice part is that he’s built a handy Python script to generate printable files for the punch cards, which encode 16 bytes of information and 4 bytes of error correction using the Reed-Solomon algorithm. That’s just enough for a password and the error correction means up to two bytes can be recovered in the case of read failure.

The reading is where this gets interesting — again, [Bitroller] provides a handy script, but this one uses OpenCV to read the entire punch card at once from a webcam image, using the contrast between a black table and the light-colored PLA cards. It’s massively overkill and would have needed a supercomputer in the days when punch cards were common I/O, but that’s what makes this a great hack.

We only have one quibble: if you use additive manufacturing, can you still call it a punch card? Nothing was punched out, after all.

If you think punch cards are totally irrelevant in the modern day, well, you might be right– but that doesn’t stop us from playing with them. If punch cards make you think of Big Iron in the early days of computing, maybe think further back– they were used for everything from Jacquard looms to the original MIDI.