Hacky Thanksgiving

It’s that time of year when we eat perhaps a little too much food, and have maybe just a few too many sips of red wine. But it’s also when we think about what we’ve been grateful for over the past year. And here at Hackaday, that’s you all: the people out there making the crazy projects that we get the pleasure of writing about, and those of you just reading along. After all, we’re just the hackers in the middle. You are all Hackaday.

And it’s also the time of year, at least in this hemisphere, when the days get far too short for their own good and the weather gets frankly less than pleasant. That means more time indoors, and if we play our cards right, more time in the lab. Supercon is over and Hackaday Europe is still far enough in the future. Time for a good project along with all of the festive duties.

So here we sit, while the weather outside is frightful, wishing you all a pleasant start to the holiday season. May your parts bin overflow and your projects-to-do-list never empty!

How To Print PETG As Transparently As Possible

PETG filament can be had in a variety of colors, just like any other. You can even get translucent or transparent forms if you want to print something vaguely see-through. But if you’re looking for a bit more visually impressive, you might like to pick up a few tips from [Tej Grewal] on making sure your prints come out as clear as possible.

Standard print settings aren’t great for transparency.

It all comes down to pathing of the 3D printer’s hot end. If it’s zigzagging back and forth, laying down hot plastic in all different orientations from layer to layer, you’re going to get a hazy, ugly, result that probably doesn’t look very see-through at all.

However, you can work around this by choosing slicer settings that make the tool pathing more suitable for producing a clearer part. [Tej] recommends going slow — as little as 20 mm/s during printing. He also states that removing top and bottom shells and setting wall loops to 1 can help to produce a part that’s entirely infill. Then, you’ll want to set infill to 100% and the direction to 0 or 90 degrees. This will ensure your hot end is just making long, straight strokes for layer after layer that will best allow light to pass through. You’ll also want to maximize nozzle flow to avoid any unsightly gaps or bubbles in your print.

[Tej] demonstrates the technique by creating a cover for a display. By using the settings in question, he creates a far more transparent plate, compared to the original part that has an ugly zig-zagging haze effect. You’re not going to get something optically clear this way; the final results are more lightly frosted, but still good.

Transparency will never be something 3D printers are great at. However, we have seen some interesting post-processing techniques that will blow your mind in this regard.

Portable Plasma Cutter Removes Rust, Packs A (Reasonable) Punch

[Metal Massacre Fab Shop] has a review of a portable plasma cutter that ends up being a very good demonstration of exactly what these tools are capable of. If you’re unfamiliar with this kind of work, you might find the short video (about ten minutes, embedded below) to be just the right level of educational.

The rust removal function has an effect not unlike sandblasting.

Plasma cutters work by forcing compressed air through a small nozzle, and ionizing it with a high voltage. This process converts the gas into a very maneuverable stream of electrically-conductive, high-temperature plasma which can do useful work, like cutting through metal. The particular unit demonstrated also has a rust removal function. By operating at a much lower level, the same plasma stream can be used to give an effect not unlike sandblasting.

Of course, an economical way to cut metal is to just wield a grinder. But grinders are slow and not very maneuverable. That’s where a plasma cutter shines, as [Metal Massacre Fab Shop] demonstrates by cutting troublesome locations and shapes. He seems a lot more satisfied with this unit than he was with the cheapest possible (and misspelled!) plasma cutter he tried last year.

And should you want a plasma cutter, and aren’t afraid to salvage components? Consider building your own.

Continue reading “Portable Plasma Cutter Removes Rust, Packs A (Reasonable) Punch”

Instant Sketch Camera Is Like A Polaroid That Draws

These days, everyone’s got a million different devices that can take a passable photo. That’s not special anymore. A camera that draws what it sees, though? That’s kind of fun. That’s precisely what [Jens] has built—an instant sketch camera!

The sketch camera looks like a miniature drawing easel, holding a rectangular slip of paper not dissimilar in size to the Polaroid film of old. The 3D-printed frame rocks a Raspberry Pi controlling a simple pen plotter, using SG90 servos to position the drawing implement and trace out a drawing. So far, so simple. The real magic is in the image processing, which takes any old photo with the Pi camera and turns it into a sketch in the first place. This is achieved with the OpenCV image processing library, using an edge detection algorithm along with some additional filtering to do the job.

If you’ve ever wanted to take Polaroids that looked like sketches when you’re out on the go, this is a great way to do it. We’ve featured some other great plotter builds before, too, just few that are as compact and portable as this one. Video after the break.

Continue reading “Instant Sketch Camera Is Like A Polaroid That Draws”

3D printed jaw with fake muscle attached

3D Printing For The Hospital Setting

Surgery is hard, there is a reason why school is so long for the profession. Making the job easier and smoother for both patients and surgeons is valuable for all parties, which is why [Mayo Clinic] is now working on including 3D printing into its more regular medicine pipeline.

Prepping for surgery often requires examining CT scans of patients to figure out, well, what they’re even going to be doing. Every body is different, and complex surgical procedures require checking to see where certain organs or features are located. This can be made much easier with a physical model of where the bones, organs, or nerves are specifically located in a patient. While this isn’t true in every case of treatment, there are even cancerous cases where custom equipment can be used to decrease side effects, such as mini-beam collimator adapters.

What if you could use the same pipeline to print what was lost from certain procedures? In a mastectomy, the breast tissue is removed, which can cause negative attention from curious gazes. So why not 3D print a custom breast? Cases like these are generally considered poor commercial investments from industry, but are relatively easy for an existing medical facility to add to treatment.

[Mayo Clinic] is far from the first to consider 3D printing in the medical setting, but seeing the technology see actual applied use rather than future seeking is exciting. Medical hacking is always exciting, and if you want to see more examples, keep sure to check out this commercially available simulator (with some free models).

Live Train Departure Screens Keep You Abreast Of Transit Developments

If you want to know when the train is coming, you could pull up a webpage on your phone, or walk all the way to the station to look at the displays there. Or, like [eastfamilyreddish], you could build a neat little train info display to decorate your desktop instead.

The build is based on the work of [gadec-uk]—who developed a train information display some time ago. It’s based around an ESP32 D1 Mini, paired with a 256 x 64 OLED screen to display relevant train information. It accesses a National Rail API for train status information—known as the Darwin LDBWS (Live Departure Board Webservice). Configuration is via a web GUI hosted by the ESP32 itself.

[eastfamilyreddish] took the concept further by adapting this hardware into a more pleasing form. The ESP32 and OLED screen are built into a neat little hanging sign setup that apes one you might expect to see at a real railway station. You might expect that 3D printing was involved, but instead, this was achieved with lasercut parts and resin casting to create something with a beautiful finish. They even went so far as to include a wireless phone charging module in the base, making the device extra useful to really earn its place on the desktop.

The fact is, around these parts we love both trains and the displays you find around them. If you’ve got a railway-adjacent project, or you’ve just built your own awesome railway, don’t hesitate to let us know on the tipsline!

Build Your Own Compact Temp Gun

Sometimes you need to know what temperature something is, but you don’t quite want to touch it. At times like these, you might want a temp gun on hand to get a good reading, like the one [Arnov Sharma] built.

The build is a relatively simple one, and is based around an Waveshare ESP32 C6 development module that comes with a small LCD screen out of the box. The microcontroller is set up to read an MLX90614 infrared temperature sensor. This device picks up the infrared energy that is emitted by objects relative to their temperature. The sensor has a great range—from -70 C to 380 C. The readouts from this sensor are then displayed on the screen. Battery power is from a small 600 mAh LiPo cell, which is managed by a IP5306 charge module.

It’s worth noting that these infrared temperature sensors aren’t infallible devices. The temperature they perceive is based on certain assumptions about factors like an objects emissivity. Thus, they don’t always give accurate readings on metallic or shiny objects, for example. It’s also important to understand the sensor’s field of view. Despite many commercial versions featuring a laser pointer for aiming, many of these infrared temperature sensors tend to average their reading over a small spot that gets larger the farther away they are from the object being measured.

Tools like portable temp guns are pretty cheap, but sometimes it’s just fun to build your own. Plus, you usually learn something along the way. Video after the break.

Continue reading “Build Your Own Compact Temp Gun”