3d printed

574 Articles

Concentric Rings Keep This Calendar Perpetually Up To Date

July 26, 2020 by 7 Comments

The variety of ways that people find to show the passage of time never ceases to amaze us. Just when you think you’ve seen them all, someone comes up with something new and unusual, like the concentric rings of this automated perpetual calendar.

What we really like about the design that [tomatoskins] came up with is both its simplicity and its mystery. By hiding the mechanism, which is just a 3D-printed internal ring gear attached to the back of each ring, it invites people in to check it out closely and discover more. Doing so reveals that each ring is hanging from a pinion gear on a small stepper motor, which rotates it to the right point once a day or once a month. Most of the clock is made from wood, with the rings themselves made using the same technique that woodturners use to create blanks for turning bowls — or a Death Star. We love the look the method yields, although it could be even cooler with contrasting colors and grains for each segment. And there’s nothing stopping someone from reproducing this with laser-cut parts, or adding rings to display the time too.

Another nice tip in this write up is the trick [tomatoskins] used to label the rings, by transferring laser-printed characters from paper to wood using nothing but water-based polyurethane wood finish. That’s one to file away for another day.

New (mis)Use For Lithophanes: Miniature Diorama Backgrounds

July 6, 2020 by 3 Comments

What’s better than a well-lit photo of a 3D-printed miniature? A photo of the miniature in a mini diorama, of course. [OrionDeHunter] shows off a clever technique that has something in common with old-timey photo stages and painted backgrounds, and (mis)uses 3D-printed lithophanes to pull it off. What [OrionDeHunter] does is use a curved and painted lithophane as a stand-in for a background, and the results look great!

Lithophanes are intended to be illuminated from behind to show an image, with thin areas showing as lighter and thicker areas darker, but when it comes to high contrast patterned images like brick walls, the same things that make a good lithophane just happen to also make a pretty good 3D model in the normal sense. No 3D scanning or photogrammetry required.

Here is the basic process: instead of creating a 3D model of a brick wall from scratch, [OrionDeHunter] simply converted an image of a brick wall (or stairs) into a curved lithophane with an online tool. The STL model of the lithophane is then 3D printed, painted, and used as a swappable background. When macro shots of the miniatures are taken, the curved background looks just right and allows for some controlled lighting. It’s a neat trick, and well applied in this project. Some sample images demonstrating how it works are just under the break.

Lithophanes were originally made using marble or thin porcelain, but a modern spin has been put on the technique with 3D printing. Enterprising hackers have even discovered ways to add color, too.

Slothbot Lives Up To Its Name

July 5, 2020 by 5 Comments

For moving about in the real world, robots can crawl along the ground or take to the sky. Both options have disadvantages, with obstacles being a problem on the ground and flying being very energy intensive. What we don’t often see are robots that move along aerial cables, which can offer the best of both worlds for certain use cases. Taking inspiration from a sloth’s slow and efficient movement through the trees, researchers from Georgia Tech created a robot to crawl slowly along a cable network and monitor the world around it, and of course named it Slothbot.

The cable switching mechanism

Slothbot trades speed for efficiency, letting it operate for very long periods on solar power alone. It does require the set up and maintenance of a cable network, but that brings the advantage of no obstacles, and the ability to stop and recharge. To us the most interesting feature is the cable switching mechanism, that allows it to navigate its way along a web of interconnected cables.

Ring gears with a section removed hold the upper part of the pulley mechanism, but can rotate it’s opening to the left or right to allow an interconnecting cable to pass through,  The body is in two pieces, with an actuated hinge in the middle to allow it to turn onto a different cable section. Each section of the body also has a powered wheel which pushes up against the cable and moves the robot along slowly. Not surprisingly, researchers say that making the cable switching mechanism reliable is the biggest challenge. It does look like the current design would not work well with thicker cable joints. Watch the video after the break for a better look at the mechanism Continue reading “Slothbot Lives Up To Its Name” →

Dremel Workstation’s New Job: Applying Threaded Inserts With Cheap Soldering Iron

June 10, 2020 by 11 Comments

Dremel has been helping people fit square pegs into round holes for years, and [concretedog] saw that the Dremel 220 Workstation — a piece of hardware similar to a drill press — could be convinced to hold a cheap soldering iron just as easily as it holds a rotary tool. A soldering iron makes an effective thermal insert tool, and the job of heating and pressing the threaded metal rings into plastic is made much easier when it can be done similar to operating a drill press. With a few modifications and a 3D-printed adapter, the thermal insert rig was born.

Whenever one is working around a design that already exists, it pays to be flexible and adjust to the unexpected. The Dremel 220 has a holder intended to clamp a rotary tool, and the original plan was to simply design and print an adapter so a soldering iron could sit in place of the rotary tool. That plan changed upon realizing that the entire rotary tool holder disconnected from the tool’s frame with a single bolt. It made much more sense to make the soldering iron replace the rotary tool holder, instead.

The resulting modified soldering iron is mounted via standoffs to a 3D-printed adapter with a copper foil heat shield. [concretedog] admits it’s not ideal from a heat management perspective, but it makes a fine prototype that seems to work well for light duty. The next step would be a metal version.

If you’re intrigued by threaded heat-set inserts, you can learn all about how to use them from Joshua Vasquez’s guide to the handy things. And should you prefer to make your own DIY press from 3D printed parts and off-the-shelf hardware, we have that covered as well.

External Battery Mod For Action Camera Does It Non-destructively

June 9, 2020 by 9 Comments

[Facelesstech] owns an SJCAM SJ4000 action camera, but the internal battery was no longer functional. Not wishing to buy a replacement and unwilling to hook up an ungainly USB cable to feed power, the solution was to design and 3D print an adapter to power the camera from a single rechargeable 14500 sized battery (which is the same size as an AA cell, and a good match for the width of the camera.)

The adapter works by mimicking the original battery, so the camera never knows the difference. A 3D-printed holder for the 14500 battery (which doubles as a GoPro compatible mount) has an extension the same size and shape of the camera’s original internal battery. The tricky part was interfacing to the power connectors buried inside the camera’s battery bay. For a solution, [Facelesstech] eventually settled on the small connectors harvested from inside a female header, using them to connect to the small blades inside the camera. We broke open a spare female 0.1″ header, shown here, to make it clear where these little pieces come from. The only other battery hardware needed are the contacts for an AA cell, but those are also easy to harvest and reuse.

The GitHub repository for the project includes STL files as well as the FreeCAD files for the parts. A video overview is embedded below.

Continue reading “External Battery Mod For Action Camera Does It Non-destructively” →

Finding Perfect Part Fits With The Goldilocks Approach (and OpenSCAD)

June 9, 2020 by 33 Comments

There is something to be said for brute force or trial-and-error approaches to problems, especially when finding a solution has an empirical element to it. [Tommy] perceived that to be the case when needing to design and 3D print servo horns that would fit factory servos as closely as possible, and used OpenSCAD to print a “Goldilocks array” from which it was possible to find a perfect match for his printer by making the trial and error process much more efficient. By printing one part, [Tommy] could test-fit dozens of options.

What made doing this necessary is the fact that every 3D printer has some variance in how accurately they will reproduce small features and dimensions. A 6.3 mm diameter hole in a CAD model, for example, will not come out as exactly 6.3 mm in a 3D-printed object. It will be off by some amount, but usually consistently so. Therefore, one way around this is to empirically determine which measurements result in a perfect fit, and use those for production on that specific 3D printer.

That’s exactly what [Tommy] did, using OpenSCAD to generate an array of slightly different sizes and shapes. The array gets printed out, servos are test-fitted to them, and whichever option fits best has its dimensions used for production. This concept can be implemented in any number of ways, and OpenSCAD makes a decent option due to its programmatic nature. Interested in OpenSCAD? It will run on nearly any hardware, and you can get up and running with the basics in probably less than ten minutes.

Rolling Your Own LED Matrix Driver, With Copper Foil Tape To The Rescue

May 30, 2020 by 1 Comment

It all started when [Damien Walsh] got his hands on some surplus LED boards. Each panel contained 100 mini-PCBs hosting a single bright LED that were meant to be to be snapped apart as needed. [Damien] had a much better idea: leave them in their 20×5 array and design a driver allowing each LED to be controlled over WiFi. He was successful (a brief demo video is embedded down below after the break) and had a few interesting tips to share about the process of making it from scratch.

The first hurdle he ran into was something most of us can relate to; it’s difficult to research something when one doesn’t know the correct terms. In [Damien]’s case, his searches led him to a cornucopia of LED drivers intended to be used for room lighting or backlights. These devices make a large array of smaller LEDs act like a single larger light source, but he wanted to be able to individually address each LED.

Eventually he came across the IS32FL3738 6×8 Dot Matrix LED Driver IC from ISSI which hit all the right bases. Three of these would be enough to control the 100-LED panel; it offered I2C control and even had the ability to synchronize the PWM of the LEDs across multiple chips, so there would be no mismatched flicker between LEDs on different drivers. As for micontroller and WiFi connectivity, we all have our favorites and [Damien] is a big fan of Espressif’s ESP32 series, and used the ESP32-WROOM to head it all up.

LED pads bridged to copper tape, with Kapton (polyimide) tape insulating any crossovers.

The other issue that needed attention was wiring. Each of the LEDs is on its own little PCB with handy exposed soldering pads, but soldering up 100 LEDs is the kind of job where a little planning goes a long way. [Damien] settled on a clever system of using strips of copper tape, insulated by Kapton (a super handy material with a sadly tragic history.) One tip [Damien] has for soldering to copper tape: make sure to have a fume extractor fan running because it’s a much smokier process than soldering to wires.

A 3D-printed baffle using tracing paper to diffuse the light rounds out the device, yielding a 20 x 5 matrix of individually-controlled rectangles that light up smoothly and evenly. The end result looks fantastic, and you can see it in action in the short video embedded below.

Continue reading “Rolling Your Own LED Matrix Driver, With Copper Foil Tape To The Rescue” →