Quick 3D-Printed Airfoils With These OpenSCAD Helpers

You know how it is. You’re working on a project that needs to move air or water, or move through air or water, but your 3D design chops and/or your aerodynamics knowledge hold you back from doing the right thing? If you use OpenSCAD, you have no excuse for creating unnecessary turbulence: just click on your favorite foil and paste it right in. [Benjamin]’s web-based utility has scraped the fantastic UIUC airfoil database and does the hard work for you.

While he originally wrote the utility to make the blades for a blower for a foundry, he’s also got plans to try out some 3D printed wind turbines, and naturally has a nice collection of turbine airfoils as well.

If your needs aren’t very fancy, and you just want something with less drag, you might also consider [ErroneousBosch]’s very simple airfoil generator, also for OpenSCAD. Making a NACA-profile wing that’s 120 mm wide and 250 mm long is as simple as airfoil_simple_wing([120, 0030], wing_length=250);

If you have more elaborate needs, or want to design the foil yourself, you can always plot out the points, convert it to a DXF and extrude. Indeed, this is what we’d do if we weren’t modelling in OpenSCAD anyway. But who wants to do all that manual labor?

Between open-source simulators, modelling tools, and 3D printable parts, there’s no excuse for sub-par aerodynamics these days. If you’re going to make a wind turbine, do it right! (And sound off on your favorite aerodynamics design tools in the comments. We’re in the market.)

Single Piece 3D-Printed PCB Vise

Making full use of the capabilities and advantages of 3D printing requires a very different way of thinking compared to more traditional manufacturing methods. Often we see designs that do not really take these advantages into account, so we’re always on the lookout for interesting designs that embrace the nature of 3D-printed parts in interesting ways. [joopjoop]’s spring-loaded PCB vise is one such ingenious design that incorporates the spring action into the print itself.

This vise is designed to be printed as a single piece, with very little post-processing required if your printer is dialed in. There is a small gap between the base plate and the springs and clamping surfaces that need to be separated with a painters knife or putty knife. Two “handles” have contours for your fingers to operate the clamping surfaces. It opens quickly for inserting your latest custom PCB.

PLA can be surprisingly flexible if the right geometry is used, and these springs are an excellent example of this. In the video below [Chuck Hellebuyck] does a test and review of the design, and it looks like it works well for hand soldering (though it probably won’t hold up well with a hot air station). Last month our own [Tom Nardi] recently reviewed a similar concept that used spiral springs designed into the printed part. While these both get the job done, [Tom’s] overall verdict is that a design like this rubber-band actuated PCB vise is a better long-term option.

It takes some creativity to get right, but printing complete assemblies as a single part, is a very useful feature of 3D printing. Just be careful of trying to make it the solution for every mechanical problem.

Tech At Home Winners Who Made The Best Of Their Quarantine

Back in April we challenged hackers to make the best of a tough situation by spending their time in isolation building with what they had laying around the shop. The pandemic might have forced us to stay in our homes and brought global shipping to a near standstill, but judging by the nearly 300 projects that were ultimately entered into the Making Tech At Home Contest, it certainly didn’t stifle the creativity of the incredible Hackaday community.

While it’s never easy selecting the winners, we think you’ll agree that the Inverse Thermal Camera is really something special. Combining a surplus thermal printer, STM32F103 Blue Pill, and OV7670 camera module inside an enclosure made from scraps of copper clad PCB, the gadget prints out the captured images on a roll of receipt paper like some kind of post-apocalyptic lo-fi Polaroid.

The HexMatrix Clock also exemplified the theme of working with what you have, as the electronics were nothing more exotic than a string of WS2811 LEDs and either an Arduino or ESP8266 to drive them. With the LEDs mounted into a 3D printed frame and diffuser, this unique display has an almost alien beauty about it. If you like that concept and have a few more RGB LEDs laying around, then you’ll love the Hive Lamp which took a very similar idea and stretched it out into the third dimension to create a standing technicolor light source that wouldn’t be out of place on a starship.

Each of these three top projects will receive a collection of parts and tools courtesy of Digi-Key valued at $500.

Runners Up

Out friends at Digi-Key were also kind enough to provide smaller grab bags of electronic goodies to the creators of the following 30 projects to help them keep hacking in these trying times:

The Making Tech At Home Contest might be over, but unfortunately, it looks like COVID-19 will be hanging around for a bit. Hopefully some of these incredible projects will inspire you to make the most out of your longer than expected downtime.

Abused Hard Drive Becomes POV Clock

We all know that there’s not much to do with an old hard drive. Once you render the platters unreadable and perhaps harvest those powerful magnets, there’s not much left of interest. Unless, of course, you turn the whole thing into a persistence-of-vision clock.

At least that’s what [Leo] did when he created “PendoLux”. The clock itself is pretty simple; like any POV project, it just requires a way to move an array of flashing LEDs back and forth rapidly enough that they can trick the eye into seeing a solid image. [Leo] put the read head mechanism of an old HDD into use for that, after stripping the platters and motor out of it first.

The voice coil and magnet of the head arm are left intact, while a 3D-printed arm carrying seven RGB LEDs replaces the old heads. [Leo] added a small spring to return the arm to a neutral position, and used an Arduino to drive the coil and flash the LEDs. Getting the timing just right was a matter of trial and error; he also needed to eschew the standard LED libraries because of his heavy use of interrupts and used direct addressing instead.

POV clocks may have dropped out of style lately — this hard drive POV clock and a CD-ROM version were posted years ago. But [Leo]’s clock is pretty good looking even for a work in progress, so maybe the style will be making a comeback.

Continue reading “Abused Hard Drive Becomes POV Clock”

Analyzing Water Quality With A Pair Of Robots

To adequately study a body of water such as a lake, readings and samples need to be taken from an array of depths and locations. Traditionally this is done by a few researchers on a small boat with an assortment of tools that can be lowered to the desired depth, which is naturally a very slow and expensive process. As the demand for ever more granular water quality analysis has grown, various robotic approaches have been suggested to help automate the process.

A group of students from Northeastern University in Boston have been working on Project Albatross, a unique combination of semi-autonomous vehicles that work together to provide nearly instantaneous data from above and below the water’s surface. By utilizing open source software and off-the-shelf components, their system promises to be affordable enough even for citizen scientists conducting their own environmental research.

The surface vehicle, assembled from five gallon buckets and aluminum extrusion, uses a Pixhawk autopilot module to control a set of modified bilge pumps acting as thrusters. With ArduPilot, the team is able to command the vehicle to follow pre-planned routes or hold itself in one position as needed. Towed behind this craft is a sensor laden submersible inspired by the Open-Source Underwater Glider (OSUG) that won the 2017 Hackaday Prize.

Using an array of syringes operated by a NEMA 23 stepper motor, the glider is able to control its depth in the water by adjusting its buoyancy. The aluminum “wings” on the side of the PVC pipe body prevent the vehicle from rolling will moving through the water. As with the surface vehicle, many of the glider components were sourced from the hardware store to reduce its overall cost to build and maintain.

The tether from the surface vehicle provides power for the submersible, greatly increasing the amount of time it can spend underwater compared to internal batteries. It also allows readings from sensors in the tail of the glider to be transmitted to researchers in real-time rather than having to wait for it to surface. While the team says there’s still work to be done on the PID tuning which will give the glider more finely-grained control over its depth, the results from a recent test run already look very promising.

How To Choose The Right GPS Module For Your Project

You’ve built a brand new project, and it’s a wonderful little thing that’s out and about in the world. The only problem is, you need to know its location to a decent degree of accuracy. Thankfully, GPS is a thing! With an off-the-shelf module, it’s possible to get all the location data you could possibly need. But how do you go about it, and what parts are the right ones for your application? For the answers to these questions, read on! Continue reading “How To Choose The Right GPS Module For Your Project”

Hackaday Podcast 080: Trucks On A Wire, Seeing Sounds, Flightless Drone, And TEA Laser Strike

Hackaday editors Elliot Williams and Mike Szczys flip through the index of great hacks. This week we learn of a co-existence attack on WiFi and Bluetooth radios called Spectra. The craftsmanship in a pneumatic drone is so awesome we don’t care that it doesn’t fly. Building a powerful TEA laser is partly a lesson in capacitor design. And join us in geeking out at the prospect of big rigs getting their juice from miles of overhead wires.

Take a look at the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Direct download (~65 MB)

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