Saving Some Coin With 3D Printed Stencils

July 23, 2026 by 12 Comments

One of the extra tools someone might need when working with surface-mount components is a solder paste stencil, which not only simplifies the application of solder paste to a PCB but increases accuracy. These metal stencils can cost an annoying amount of money and take time to get delivered, so this group has developed a method to 3D print them instead.

Starting with a PCB design in one’s tool of choice, the Gerber files can be sent to the online Stenchill tool to generate the stencil. Alternatively, a KiCad plugin exists as well. The tool will output files for a 3D printer from there. An FDM printer is required, with either PLA or PETG filament, and some configuration in the slicer is needed to get the accuracy required for a useful stencil. But once that’s all set up, the printer can output a perfectly usable stencil at a fraction of the cost, and without having to wait days for delivery through the mail.

It’s not all upside, though. Although it might be better than applying solder paste with a syringe on a massive board or doing more than one smaller board by hand, it may not be as good as a metal stencil for extremely small pads. But for those who often find themselves using metal stencils and dealing with the downsides that come with them, this could be a viable alternative, especially when prototyping.

If you have a laser cutter handy, that opens up some additional options for stencil production.

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60 FPS NES Emulator On ESP32

July 22, 2026 by 9 Comments

At least in theory, video games are more resistant to becoming lost media thanks to their digital nature — they’re easy to copy and emulators have saved many titles that are otherwise locked in corporate vaults. But emulators give us something beyond simple preservation: they can also be used to enhance games well beyond the capabilities of the original systems while still preserving the souls of the games, as this NES emulator manages to do.

The emulator is called Anemoia-ESP32, and as its name suggests is a re-write of the Anemoia emulator specifically built for the ESP32. By modern standards these little chips don’t pack much of a punch, but compared to original NES hardware they’re more than up to the task of gaming. This project aims to recreate the Nintendo Entertainment System experience as faithfully as possible, hitting 60 FPS in most instances, as well as maintaining full audio emulation. Running on an ESP32 enables some truly small handheld options that would be difficult to achieve with more traditional platforms for emulation. There are some PCBs available here as well, but aren’t required to explore this project with.

As far as extra features compared to original NES hardware, the emulator does support save states and has a number of other settings improvements. Installation is as easy as flashing any other firmware image onto an ESP32, which these days can even be done from the browser. No word on whether or not it will eventually support emulating dual Picture Processing Units, but we can hope.

Art of 3D printer in the middle of printing a Hackaday Jolly Wrencher logo

Giving Resin 3D Printers Another Shot After Six Years

July 21, 2026 by 21 Comments

My initial experience with a 3D printer came in 2020, when I got access to a buddy’s Creality LD-002R SLA printer. This was one of those awkward transition phases for SLA printers, where inefficient RGB LCDs finally got replaced by monochrome LCD panels, thus massively reducing the required exposure time and increasing the LCD panel’s lifespan.

The closely related Creality LD-002H is a monochrome SLA printer, but as this wasn’t the one that this friend opted for we had to learn the ropes on this more old-school printer. In terms of specifications this meant a build volume of 119 mm x 65 mm x 160 mm to play with and a claimed 26.1 µm resolution. Despite some struggles along the way, this machine churned out impressively high levels of detail with whatever cheap resin we threw at it, and even the post-printing processing became easy once we added a flex plate to the build plate and tweaked the cleaning and curing steps.

Despite all these positives, we both drifted away from resin printing, mostly due to the still messy and smelly printing process. FDM printers seemed like a better deal, especially after said buddy got his mittens on a used IDEX FDM printer. I would eventually go through a rather loathsome Creality Ender V2 experience before ending up with my current-day Elegoo Neptune 4, and resin printing seemed to be a thing of the past for me. Until recently, that is.

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Java Ring Restored After Nearly 30 Years

July 21, 2026 by 18 Comments

Back in the late 90s when absolutely everybody knew that Java was going to become the one programming language to rule them all, the Java Ring was handed out to folks at Java developer conferences as an example of how it was going to revolutionize smart wearable devices. Recently [Daisuke Yamazaki] got his mittens on one of these collector’s items to see about reviving it.

We talked about these rings and associated iButton devices before, with their intended use being primarily to act as authentication keys. For the Java Ring, this use was mostly just used as a kind of gag, whereby visitors to these conferences could specify their coffee preferences at a terminal, having this programmed into the ring so that they could get their desired cup of literal java at various bean juice dispensers around the conference site.

Talking to one of these iButton devices requires a so-called Blue Dot adapter, which [Yamazaki-san] purchased along with the ring. Although the device happily responded on the 1-wire bus, figuring out how to interact with the original Java-based firmware and answering the question of how much of the original information of someone’s coffee preferences in ’98 were retained would require more sleuthing.

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Seven Ways To Install Magnets Into Your 3D Prints

July 19, 2026 by 12 Comments

Magnets are awesome, so it’s no wonder we love to add them to our 3D prints. Doing so in a way that will actually last is harder, with thermal creep being one reason a simple friction fit will loosen over time, and using super glue to hold a magnet in place can be messy. In a recent video, [Slant 3D] covers seven ways to install magnets in 3D prints without resorting to glue, along with the advantages and disadvantages of each.

With friction, the argument is that you can still use them, but you’d want to use something like cylindrical magnets rather than flat magnets to increase the friction with the thermoplastic. Using an arbor press rather than human primate hand power is also beneficial.

Rather than installing magnets halfway through a print with all the logistics that entails, you can use side slots to install said magnet into, which is much easier, but as with all embedded magnets, you get that plastic barrier between the magnet and its target.

Other methods involve using a bit of extra material that you need to push the magnet past, using something like an arbor press, so the magnets should never just fall out. A wildcard here: spherical magnets, which can be locked in using a similar method, while automatically orienting themselves to an opposing magnet.

The final tip is to never use two magnets in a magnetic lock. Instead, use a cheaper ball bearing or a similar plain metal part on one side instead. Magnets tend to be much more brittle than whatever stainless steel ball bearing or washer you can use on the other side.

Of course, people will always try to install magnets during an FDM print, but before they try to do that anyway, they really should learn about the fascinating ways in which magnets can ruin print beds, destroy nozzles, and otherwise make a total mess of a print. Magnets seem magical. Maybe they are.

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Write 2D And 3D Games In Modern MoonBASIC

July 18, 2026 by 8 Comments

One of the major strengths of the BASIC programming languages has always been their no-fuss setup and rich set of commands for operations that would take considerably more work in a bare-bones language like C. MoonBASIC continues this legacy with a BASIC variant optimized for both 2D and 3D game development.

Included in the package are Raylib, Box2D, and Jolt, whose functionality is exposed via over 4,200 commands in their respective namespaces. You can also download a whole IDE package based around VS Code, use it on the command line, or add it to an existing VS Code installation.

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ESP32-driven Roulette Wheel Could Have Used A 555, But That Didn’t Have WiFi

July 18, 2026 by 5 Comments

Sometimes you see a project and immediately, before going into the details, your mind throws up the old refrain: “coulda used a 555” — well, [Hulk] actually agrees when it comes to his ESP32-based, 3D printed roulette wheel. The first version did use a 555, but then feature creep kicked in and the final project ended up with an ESP32 instead. We’ve all been there.

The roulette wheel circuit is retained from the 555 version, with the ESP32 providing clock pulses instead of the venerable oscillator chip — it uses a pair of decade counters to create the chase effect of the LED around the wheel. With a handsome printed enclosure, [Hulk] could have stopped there, but then he’d have to keep track of scoring and the like manually like some kind of dark age peasant. It’s the 21st century, we have computers to to that for us!

Now, even though the ESP32 is still driving the LED chase via the decade counters, it can keep track of where the “ball” of light lands, and reports that via WiFi or serial. While it would have been an option to run the whole game on the ESP32. [Hulk] just has those values put into an SQL database on a server, which also runs the game front-end via PHP. The resulting web page lets two players make their bets and track their wins and losses over time. You can see that in action in the video embedded below.

Overkill? Sure, but we suspect [Hulk] already had the equipment and experience to make this the fastest way to get a playable game. There are easy ways to serve web content from an ESP32, but the easiest tool to use is always the one in your back pocket, right?

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