A red hot crucible is held with metal tongs above a white plaster mold. The mold is held in a bright pink silicone sleve atop a metal pan on a wooden workbench. Red cheese wax holds the sleeve to a metal funnel connected to a vacuum cleaner.

Lost Print Vacuum Casting In A Microwave

March 2, 2024 by Navarre Bartz 14 Comments

Hacks are rough around the edges by their nature, so we love it when we get updates from makers about how they’ve improved their process. [Denny] from Shake the Future has just provided an update on his microwave casting process.

Sticking metal in a microwave certainly seems like it would be a bad idea at first, but with the right equipment it can work quite nicely to develop a compact foundry. [Denny] walks us through the process start to finish in this video, including how to build the kilns, what materials to use, and how he made several different investment castings using the process. The video might be worth watching just for all the 3D printed tools he’s built to aid in the process — it’s a great example of useful 3D prints to accompany your fleet of little plastic boats.

A lot of the magic happens with a one minute on and six minutes off cycle set by a simple plug timer. This allows a more gradual ramp to burn out the PLA or resin than running the microwave at full blast which can cause some issues with the kiln, although nothing catastrophic as demonstrated. Vacuum is applied to the mold with a silicone sleeve cut from a swimming cap while pouring the molten metal into the mold to draw the metal into the cavities and reduce imperfections.

We appreciate the shout out to respirators while casting or cutting the ceramic fiber mat. Given boric acid’s effects, [PDF] you might want to use safety equipment when handling it as well or just use water as that seems like a valid option.

If you want to see where he started check out this earlier version of the microwave kiln and how he used it to make an aluminum pencil.

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The Latest Advancements In Portable N64 Modding

February 22, 2024 by Donald Papp 6 Comments

[Chris Downing] has been in the mod scene a long time, and his 5th GeN64 Portable is his most modern portable Nintendo 64 yet. The new build has an improved form factor, makes smart use of 3D printing and CNC cutting, efficiently uses PCBs to reduce wiring, and incorporates a battery level indicator. That last feature is a real quality of life improvement, nicely complementing the ability to charge over USB-C.

What’s interesting about builds like this is that it’s all about the execution. The basic parts required to mod a classic games console into a portable unit are pretty well understood, and off-the-shelf modules like button assemblies exist to make the job far easier than it was back in the day when all had to be done from scratch. We’ve admired [Chris Downing]’s previous builds, and what differentiates one mod from another really comes down to layout and execution, and that’s where the 5th GeN64 Portable shines. Continue reading “The Latest Advancements In Portable N64 Modding” →

Watch The OpenScan DIY 3D Scanner In Action

February 19, 2024 by Donald Papp 20 Comments

[TeachingTech] has a video covering the OpenScan Mini that does a great job of showing the workflow, hardware, and processing method for turning small objects into high-quality 3D models. If you’re at all interested but unsure where or how to start, the video makes an excellent guide.

We’ve covered the OpenScan project in the past, and the project has progressed quite a bit since then. [TeachingTech] demonstrates scanning a number of small and intricate objects, including a key, to create 3D models with excellent dimensional accuracy.

[Thomas Megel]’s OpenScan project is a DIY project that, at its heart, is an automated camera rig that takes a series of highly-controlled photographs. Those photographs are then used in a process called photogrammetry to generate a 3D model from the source images. Since the quality of the source images is absolutely critical to getting good results, the OpenScan hardware platform plays a pivotal role.

Once one has good quality images, the photogrammetry process itself can be done in any number of ways. One can feed images from OpenScan into a program like Meshroom, or one may choose to use the optional cloud service that OpenScan offers (originally created as an internal tool, it is made available as a convenient processing option.)

It’s really nice to have a video showing how the whole workflow works, and highlighting the quality of the results as well as contrasting them with other 3D scanning methods. We’ve previously talked about 3D scanning and what it does (and doesn’t) do well, and the results from the OpenScan Mini are fantastic. It might be limited to small objects, but it does a wonderful job on them. See it all for yourself in the video below.

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Electric Boomerang Does Laps

February 2, 2024 by Danie Conradie 5 Comments

Boomerangs are known for their unique ability to circle back to the thrower, but what if you could harness this characteristic for powered for free flight? In a project that spins the traditional in a new direction, [RCLifeOn] electrifies a boomerang to make it fly laps.

The project started with several of the 3D printed boomerang designs floating around on the internet, and adding motor mounts to the tips. [RCLifeOn] is no stranger to RC adventures, and his stockpile of spare parts from previous flying and floating projects proved invaluable. He added motor mounts and mounted all the electronics, including a RC receiver for controlling the throttle, but first iteration didn’t have enough lift, so the boomerang and motors were scaled up.

[RCLifeOn] launched the contraptions by letting them spin on the end of a stick until they achieve lift-off. The second iteration still couldn’t quite get into the air, but after increasing the blade angles using a heat gun it was flying laps around the field.

Although we’ve seen spinning drones that are controllable, it would be no small control systems challenge to make it completely RC controlled. In the meantime this project is a fun, if somewhat risky way to mix the traditional with modern tech.

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The Case Against Calibration Cubes

February 2, 2024 by Danie Conradie 27 Comments

Calibration cubes have long been a staple for testing and adjusting 3D printers, but according to [Stefan] of CNC Kitchen, they’re not just ineffective—they could be leading us astray. In the video after the break he explains his reasoning for this controversial claim, and provides a viable alternative.

Such cubes are often used to calibrate the steps per millimeter for the printer’s steppers, but the actual dimensions of said cube can be impacted by over or under extrusion, in addition to how far the machine might be out of alignment. This can be further exacerbated by measuring errors due to elephant’s foot, over extruded corners, or just inaccuracies in the caliper. All these potential errors which can go unnoticed in the small 20 x 20 mm cube, while still leading to significant dimensional errors in larger prints

So what’s the solution? Not another cube. It’s something called the “CaliFlower” from [Adam] of Vector 3D. This is not a typical calibration model — it’s carefully designed to minimize measurement errors with ten internal and external measuring points with stops for your calipers. The model costs $5, but for your money you get a complete guide and spreadsheet to calculate the required of corrections needed in your firmware or slicer settings.

If you regularly switch materials in your 3D printer, [Stefan] also advises against adjusting steps per millimeter and suggests defining a scaling factor for each material type instead. With this method validated across different materials like PLA, PETG, ABS, and ASA, it becomes evident that material shrinkage plays a significant role in dimensional inaccuracy, not just machine error. While [Stefan] makes a convincing case against the standard calibration cube for dimensional calibration, he notes that is is still useful for evaluating general print quality and settings.

[Stefan] has always done rigorous testing to back his claims, and this video was no different. He has also tested the effects of filament color on part strength, the practicality of annealing parts in salt, and even printing custom filament.

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3D Printed Axial Compressor Is On A Mission To Inflate Balloons

January 29, 2024 by Donald Papp 5 Comments

[Let’s Print] has been fascinated with creating a 3D printed axial compressor that can do meaningful work, and his latest iteration mixes FDM and SLA printed parts to successfully inflate (and pop) a latex glove, so that’s progress!

Originally, the unit couldn’t manage even that until he modified the number and type of fan blades on the compressor stages. There were other design challenges as well. For example, one regular issue was a coupling between the motor and the rest of the unit breaking repeatedly. At the speeds the compressor runs at, weak points tend to surface fairly quickly. That’s not stopping [Let’s Print], however. He plans to explore other compressor designs in his quest for an effective unit.

Attaching motor shafts to 3D printed devices can be tricky, and in the past we’ve seen a clever solution that is worth keeping in mind: half of a spider coupling (or jaw coupling) can be an economical and effective way to attach 3D printed things to a shaft.

While blowing up a regular party balloon is still asking too much of [Let’s Print]’s compressor as it stands, it certainly inflates (and pops) a latex glove like nobody’s business.

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Hotshot 3D Printed Hovercraft Is Devastatingly Fast

January 27, 2024 by Lewin Day 7 Comments

These days, it’s pretty cheap and easy to build your own little RC hovercraft. [ValRC] demonstrates just that with a hovercraft build that is surprisingly nimble, and fast to boot.

The build started with a design [ValRC] found online. It was simple enough to print and assemble, needing only a pair of a brushless motors, a speed controller, a receiver, and a servo to run the show. The design uses a plastic bag as a skirt, assembled around a 3D printed frame. That proved to be the hardest part of the build, as hot glue didn’t want to play nice with the thin garbage bag.

Even despite the challenges, once assembled, the hovercraft performed well. It readily slid around on a cushion of air, drifting across asphalt with abandon. Upgrades included a better rudder and a skirt made of thicker and more resilient plastic. The final craft looked mesmerizing as it glided over the smooth concrete of a parking garage with ease.

A hovercraft is, honestly, one of the cooler printable projects for beginners. All you need is a simple design, some powerful motors, and you’re good to go.

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