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

June 10, 2020 by Donald Papp 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 Donald Papp 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.

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

June 9, 2020 by Donald Papp 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 Donald Papp 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.

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Self-Shutting Face Mask Is Hacker’s Delight

May 19, 2020 by Moritz v. Sivers 28 Comments

Most of us currently have to deal with wearing face masks in our daily life. An experience that is not entirely pleasurable as it is more difficult to breathe under the mask and can become hot after a while. In addition, you have to take off the mask whenever you want to eat or drink. [DesignMaker] has attempted to solve these problems by creating a mask with an opening that shuts automatically when other people are nearby.

While homemade masks are usually made from fabric [DesignMaker]’s version is much more to a hacker’s taste and includes 3D-printed parts, an Arduino Nano, PIR sensors, an SG90 servo, and some Neopixels. [DesignMaker]’s background in industrial design certainly helped him when modeling the mask as it looks just plain awesome.

His goal was to use PIR sensors to detect when a person is moving nearby. The servo then shuts an opening located at the mouth part of the mask. However, he soon found out that the mask often shuts when nobody is around. The reason is that the sensor can be triggered by ambient IR radiation when it is moving by itself. In the end [DesignMaker] decided that having the mask shut when you are moving is not a bug, it’s a feature.

Of course, the mask is just a prop and should not be used as protective equipment. As shown in the video below, also the false triggering of the PIR sensors can be annoying at times. But [DesignMaker] is already thinking of improvements like having the mask properly sealed with fabric or replacing the PIR sensors by a camera with face detection.

If you want to learn how to sew a proper fabric face mask have a look here. It’s a lot less ridiculous, but a lot more effective. You can’t have everything.

Video after the break.

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Whiteboard Plotter Rocks Three Colors And An Eraser

May 18, 2020 by Donald Papp 11 Comments

AutoWhiteboardBot’s business end, with three markers.

[td0g]’s AutoWhiteboardBot is not just any 3D printed whiteboard plotter, because it also sports a triple-marker carrier and on-board eraser! The device itself hangs from stepper motors, which take care of moving the plotter across the whiteboard, and the trick to making the three colors work was to incorporate retractable dry-erase markers. A spherical Geneva drive-based assembly on the plotter rotates the pen cartridge, and a plunger activates the chosen color. Erasing, arguably the easiest thing to do on a whiteboard, is done by a piece of felt. 3D printed parts are on Thingiverse and [td0g] says software is coming soon. It’s a clever device, especially the method of accommodating multiple colors with retractable markers.

AutoWhiteboardBot hangs from motors which pull it around, but we’ve also seen a SCARA-type robot writing away on a whiteboard. Watch the video embedded below, which begins with sped-up footage of AutoWhiteboardBot drawing in different colors as it slides across the board surface.

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Aladdin Lamp Shoots Flames With A Snap Of Your Fingers

May 13, 2020 by Moritz v. Sivers 4 Comments

Despite their dangers, even Marie Kondo would not convince us to abandon flamethrower projects because they literally spark joy in us. To make this flame shooting Aladdin lamp [YeleLabs] just used a 3D printer and some basic electronics.

The lamp body consists of two 3D-printed halves held together by neodymium magnets. They house a 400 kV spark generator, a fuel pump plus tank, and a 18650 Li-ion battery. The fuel pump is actually a 3 V air pump but it can also pump liquids at low pressure. As fuel [YeleLabs] used rubbing alcohol that they mixed with boric acid to give the flame a greenish tint. The blue base at the bottom of the lamp houses the triggering mechanism which magically lights up the lamp when you snap your fingers. This is achieved by a KY-038 microphone module and KY-019 relay module connected to a Digispark ATTiny85 microcontroller. When the microphone signal is above a certain threshold the relay module will simultaneously switch on the spark generator and fuel pump for 150 ms.

Although they proclaim that the device is a hand sanitizer it is probably safer to stick to using soap. The project still goes on the list of cool flamethrower props right next to the flame shooting Jack-o-Lantern.

Video after the break.

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