Print Your Next LED Bezel

December 27, 2025 by Donald Papp No comments

LED bezels (also known as LED panel-mount holders) are great, so how about 3D printing the next ones you need? Sure, they’re inexpensive to purchase and not exactly uncommon. But we all know that when working on a project, one doesn’t always have everything one might need right at hand. At times like that, 3D printing is like a superpower.

Printing a part you find yourself short of can be a lifesaver.

[firstgizmo]’s design is made with 3D printing in mind, and most printers should be able to handle making them. Need something a little different? You’re in luck because the STEP files are provided (something we love to see), which means modifications are just a matter of opening them in your favorite CAD program.

There’s not even any need to export to an STL after making tweaks, because STEP support in slicer programs is now quite common, ever since PrusaSlicer opened that door a few years ago.

Not using 5 mm LEDs, and need some other size? No problem, [firstgizmo] also has 3 mm, 8 mm, and 10 mm versions so that it’s easy to mount those LEDs on a panel. Combined with a tool that turns SVG files into multi-color 3D models, one can even make some panels complete with color and lettering to go with those LEDs. That might be just what’s needed to bring that midnight project to the next level.

Cookie Launcher Makes You Catch Your Own Snack

December 25, 2025 by Donald Papp 2 Comments

Holiday cookies are a joy, and to make things a bit more fun, [The Skjegg] created the Cookie Launcher. At the touch of a button, a door opens and the tin launches a cookie (and perhaps a few crumbs) skyward. Catching it is up to the operator, but since the tin can hold up to 40 cookies at once (39 in a magazine and 1 in the launcher), there’s enough to get some practice in.

The design is a real thing of beauty, from the rotary cookie holder to the ejector. Individual cookies are held in a pan-style magazine that rotates until a tasty disk is lined up with the ejector. The red separators aren’t just for show, either. The little inward protrusion on each one interacts with an optical sensor to ensure the system always knows when things are lined up.

The launcher design is pretty neat, too. There’s a platform that uses two smooth bolts as guides, and elastic bands to store energy. A motor cranks it downward, where it locks into place. The rotary magazine then turns to line up a cookie, which gravity feeds into the launcher by rolling down an incline. When a cookie is in place, a door in the lid opens and the launcher platform releases, sending the cookie skyward.

The original concept for the Cookie Launcher involved voice activation, but training the voice module to trigger on custom Norwegian commands wasn’t very reliable. Luckily, a button is far more obedient. It may be a bit less magical to use, but in our opinion the physicality of a button push meshes perfectly well with the requirement to catch your own cookie.

You can get a good look at the operation and a detailed tour of the insides in the video, embedded below. Thanks to [Rohit] for sending in the tip!

If airborne cookies aren’t your bag, check out one a very different approach to hands-free cookie dispensing.

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Christmas Ornament Has Hidden Compartment, Clever Design

December 22, 2025 by Donald Papp 2 Comments

If you need something clever for a gift, consider this two-part 3D-printed Christmas ornament that has a small secret compartment. But there’s a catch: the print is a challenging one. So make sure your printer is up to the task before you begin (or just mash PRINT and find out).

Want a challenging print that’s also useful? This two-piece ornament has a small gift area inside, and prints without supports.

This design is from [Angus] of [Maker’s Muse] and it’s not just eye-catching, but meticulously designed specifically for 3D printing. In fact, [Angus]’s video (embedded under the page break) is a great round-up of thoughtful design for manufacture (DFM) issues when it comes to filament-based 3D printing.

The ornament prints without supports, which is interesting right off the bat because rounded surfaces (like fillets, or a spherical surface) facing the build plate — even when slightly truncated to provide a flat bottom — are basically very sharp overhangs. That’s a feature that doesn’t generally end up with a good surface finish. [Angus] has a clever solution, and replaces a small section with a flat incline. One can’t tell anything is off by looking at the end result, but it makes all the difference when printing.

There are all kinds of little insights into the specific challenges 3D printing brings, and [Angus] does a fantastic job of highlighting them as he explains his design and addresses the challenges he faced. One spot in particular is the flat area underneath the hang hole. This triangular area is an unsupported bridge, and because of its particular shape, it is trickier to print than normal bridges. The workable solution consists of countersinking a smaller triangle within, but [Angus] is interested in improving this area further and is eager to hear ideas on how to do so. We wonder if he’s tried an approach we covered to get better bridges.

Want to print your own? 3D files are available direct from [Angus]’s site in a pay-what-you-like format. If your 3D printer is up to it, you should be able to make a few before Christmas. But if you’d prefer to set your sights on next year with something that uses power and hardware, this tiny marble machine ornament should raise some eyebrows.

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3D Printing And Metal Casting Are A Great Match

December 15, 2025 by Donald Papp 23 Comments

[Chris Borge] has made (and revised) many of his own tools using a combination of 3D printing and common hardware, and recently decided to try metal casting. Having created his own tapping arm, he tries his hand at aluminum casting to create a much more compact version out of metal. His video (embedded below) really shows off the whole process, and [Chris] freely shares his learning experiences in casting his first metal tool.

The result looks great and is considerably smaller in stature than the 3D-printed version. However, the workflow of casting metal parts is very different. The parts are much stronger, but there is a lot of preparation and post-processing involved.

Metal casting deals with molten metal, but the process is otherwise very accessible, and many resources are available to help anyone with a healthy interest.

The key to making good castings is mold preparation. [Chris] uses green sand (a mixture of fine sand and bentonite clay – one source of the latter is ground-up kitty litter) packed tightly around 3D printed parts inside a frame. The packed sand holds its shape while still allowing the original forms to be removed and channels to be cut, creating a two-part mold.

His first-time castings have a rough surface texture, but are perfectly serviceable. After some CNC operations to smooth some faces and drill some holes, the surface imperfections are nothing filing, filler, and paint can’t handle.

To cast molten metal, there really isn’t any way around needing a forge. Or is there? We have seen some enterprising hackers repurpose microwave ovens for this purpose. One can also use a low-temperature alloy like Rose’s Metal, or eschew molten liquid altogether and do cold casting, which uses a mixture of resin and metal powder instead.

The design files for [Chris]’s tapping arm are available from links in the video description, and he also helpfully provides links to videos and resources he found useful. Watch it in the video, embedded just below.

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Trace Line Clock Does It With Magnets

December 8, 2025 by Donald Papp 9 Comments

We love a good clock project, and [byeh_ in] has one with a design concept we don’t believe we have seen before. The Trace Line Clock has smooth lines and a clean presentation, with no sockets or visible mechanical fixtures.

Reading the clock is quite straightforward once one knows what is going on. At its heart, the unmarked face is much like any other analog clock face, and on the inside is a pretty normal clock movement. The inner recessed track on the face represents hours, and the outer is minutes. The blue line connects the two, drawing a constantly changing line.

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How To Design 3D Printed Pins That Won’t Break

December 1, 2025 by Donald Papp 9 Comments

[Slant 3D] has a useful video explaining some thoughtful CAD techniques for designing 3D printed pins that don’t break and the concepts can be extended to similar features.

Sure, one can make pins stronger simply by upping infill density or increasing the number of perimeters, but those depend on having access to the slicer settings. If someone else is printing a part, that part’s designer has no actual control over these things. So how can one ensure sturdier pins without relying on specific print settings? [Slant 3D] covers two approaches.

The first approach includes making a pin thick, making it short (less leverage for stress), and adding a fillet to the sharp corner where the pin meets the rest of the part. Why? Because a rounded corner spreads stress out, compared to a sharp corner.

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The Eleven-Faced Die That Emulates Two Six-sided Dice

November 28, 2025 by Donald Papp 28 Comments

Rolling two six-sided dice (2d6) gives results from 2 to 12 with a bell curve distribution. Seven being the most common result, two and twelve being the least common. But what if one could do this with a single die?

This eleven-sided die has a distribution matching the results of 2d6.

As part of research Putting Rigid Bodies to Rest, researchers show that a single eleven-sided asymmetric shape can deliver the same results. That is to say, it rolls numbers 2 to 12 in the same distribution as 2d6. It’s actually just one of the oddball dice [Hossein Baktash] and his group designed so if you find yourself intrigued, be sure to check out the 3D models and maybe print your own!

The research behind this is a novel method of figuring out what stable resting states exist for a given rigid body, without resorting to simulations. The method is differentiable, meaning it can be used not just to analyze shapes, but also to design shapes with specific properties.

For example, with a typical three-sided die each die face has an equal chance of coming up. But [Hossein] shows (at 8:05 in the video, embedded below) that it’s possible to design a three-sided die where the faces instead have a 25%-50%-25% distribution.

How well do they perform in practice? [Hossein] has done some physical testing showing results seem to match theory, at least when rolled on a hard surface. But we don’t think anyone has loaded these into an automated dice tester, yet.

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