Texture Adds Stiffness To 3D Parts

April 27, 2021 by 16 Comments

[Stefan] is always looking for a way to make stronger and better 3D prints. His latest experiments involve using a texture on thin plastic parts to increase stiffness. You can see the texture pattern in the banner above and the video below.

While a lot of people looked at IdeaMaker’s new texturing feature as something for cosmetics, [Stefan] thought of sheet metal products that often use bead patterns to increase stiffness and strength. Can patterned plastic be stiffer than ordinary printed plastic? Turns out, the answer is yes.

Continue reading “Texture Adds Stiffness To 3D Parts” →

The Evil Crow Is Ready To Cause Some RF Mayhem

April 27, 2021 by 34 Comments

There’s no doubt that the RTL-SDR project has made radio hacking more accessible than ever, but there’s only so far you can go with a repurposed TV tuner. Obviously the biggest shortcoming is the fact that you can only listen to signals, and not transmit them. If you’re ready to reach out and touch someone, but don’t necessarily want to spend the money on something like the HackRF, the Evil Crow RF might be your ideal next step.

This Creative Commons licensed board combines two CC1101 radio transceivers and an ESP32 in one handy package. The radios give you access to frequencies between 300 and 928 MHz (with some gaps), and the fact that there are two of them means you can listen on one frequency while transmitting on another; opening up interesting possibilities for relaying signals. With the standard firmware you connect to a web interface running on the ESP32 to configure basic reception and transmission options, but there’s also a more advanced RFQuack firmware that allows you to control the hardware via Python running on the host computer.

Using the Evil Crow RF without a computer.

One particularly nice feature is the series of buttons located down the side of the Evil Crow RF. Since the device is compatible with the Arduino IDE, you can easily modify the firmware to assign various functions or actions to the buttons.

In a demonstration by lead developer [Joel Serna], the physical buttons are used to trigger a replay attack while the device is plugged into a standard USB power bank. There’s a lot of potential there for covert operation, which makes sense, as the device was designed with pentesters in mind.

As an open source project you’re free to spin up your own build of the Evil Crow RF, but those looking for a more turn-key experience can order an assembled board from AliExpress for $27 USD. This approach to hardware manufacturing seems to be getting popular among the open source crowd, with the Open-SmartWatch offering a similar option.

[Thanks to DJ Biohazard for the tip.]

Logic Flows, Literally, In This Water Adder

April 26, 2021 by 31 Comments

A lot of elementary electronic texts use water as an analogy for electricity. You know, pressure is voltage, flow is current, and pipe diameter is resistance. It is ironic, then, that some people use fluids to build logic gates and, in fact, you can make any logic circuit you like using nothing but water flowing through some structures. Don’t think so? Have a look at the video from [Steve Mould] below.

Fluidic logic isn’t anything new, but it has always been a bit exotic. Usually, replacing electrons with water or even air — which is a kind of fluid — means you are trying to operate in a tough environment or have some other special need. As far as we can tell, [Steve] did it just because he could, and we get that.

Continue reading “Logic Flows, Literally, In This Water Adder” →

Retrotechtacular: Renewable Energy, 1948 Edition

April 26, 2021 by 22 Comments

If you’ve got 10 minutes, how about a quick break to watch a video about renewable clean electric power? Must be a recent video, right? Nope. The Coronet Instruction Film below is from 1948 and covers using rivers to generate power. Hydropower isn’t a new idea, of course, and the film starts out with an old-fashioned water wheel. That’s not really what they are driving at, though.

The announcer sounds just like the guy who narrated all the film strips you saw in school. There are some good vintage shots of Niagra Falls and some other dams. The video also makes some economic arguments about hydroelectric versus coal and why some rivers aren’t suitable for power generation.

Continue reading “Retrotechtacular: Renewable Energy, 1948 Edition” →

Where We’re Going, We Don’t Need Keycaps

April 26, 2021 by 14 Comments

Just when we thought we’d seen the peak of ergonomic, split keyboards, along comes [Peter Lyons] with the Squeezebox — an adjustable, column-staggered, streamlined beauty with 21 keys per hand. Much like the Kinesis Advantage and the Dactyl, the user’s fingers are allowed to dangle comfortably and stay in their naturally curled position, moving as little as possible between keys, rows, and columns. But the Squeezebox goes a few steps farther to reduce finger travel.

For starters, each column of keys is adjustable on the fly in the Y-direction by loosening the screw and sliding it until it’s just right. The columns are also adjustable in the Z-direction, but for now, this requires reprinting a few parts. In case you didn’t notice, the grid is pretty tightly packed, and those low-profile Kailh choc switches are naked to the world, mostly because keycaps wouldn’t fit anyway.

At that angle, there’s no reaching required at all between the middle and bottom rows. The 100° corner that they form both invites and supports chording — that’s pressing multiple keys simultaneously to do some action. There’s no real need to reach for the top row, either, because [Peter] merely moves his finger upward in the Z-direction a little bit to hit those. The similarly-angled thumb clusters are chord-able as well, and their position relative to the mainland is adjustable thanks to a grid of holes that are meant for threaded inserts. Genius!

For the next version, [Peter] plans to bring the three sets of thumb cluster switches closer together, and arrange them like a tri-fold science fair display board. Be sure to check out the super cool but somewhat impossible-to-solder prototypes in the build log, and stay for more stuff in the huge build gallery. Typing demo is after the break.

Still too much travel for your taste? How about a 5-way for each finger?

Continue reading “Where We’re Going, We Don’t Need Keycaps” →

Pneumatic Can Crusher Awaits Your Command

April 26, 2021 by 22 Comments

A powerful robot awaiting for a verbal command to crush its foes might sound like something from a science fiction film, but now it’s a permanent fixture of the [Making Stuff] garage.  (Video, embedded below.) Thankfully this robot’s sworn enemy are aluminum cans, and the person controlling it with their voice isn’t a maniacal scientist, just a guy who’s serious about recycling. Well, we hope so anyway.

The star of the show is a heavy duty wall-mounted can crusher that [Making Stuff] built from some scrap steel and a pneumatic cylinder hooked up to the garage’s compressed air system. A solenoid operated valve allows an Arduino with attached ESP-01 to extend the cylinder whenever the appropriate command comes over the network. In this case, the goal was to tie the crusher into Google Assistant so a can would get smallified whenever one of Google’s listening devices heard the trigger phrase.

Note the ejector air line.

Obviously, those who’d rather keep Big Data out of their recycling bin don’t have to go down the same path. But that being said, having to give a specific voice command to activate the machine does provide a certain level of operational safety. At least compared to trusting some eBay sensor to tell the difference between an aluminum can and a fleshy appendage.

After crushing a few cans with his new toy, [Making Stuff] noticed a fairly troubling flaw in the design. Each time a can was crushed he had to reach into the maw of the machine to push its little flattened carcass out of the way. In other words, he was one bad line of code away from having one good hand.

The solution ended up being a new hose that runs from the exhaust port of the valve to the crushing chamber: once the cylinder retracts, the air exiting the valve pushes the crushed can out the rear of the machine and into a waiting pail underneath. Very slick.

Even if you’re not interested in the voice control aspect, this is a great design to base your own can crusher on. While it’s always a treat when a fully automatic crusher comes our way, we’ll admit the challenges of getting one to work reliably probably aren’t worth the hassle.

Continue reading “Pneumatic Can Crusher Awaits Your Command” →

Indian Makers Respond To The COVID-19 Pandemic By Producing Oxygen Concentrators

April 26, 2021 by 56 Comments

We’ve all spent the last year or more under the shadow of the COVID-19 pandemic, and though some of us may have been vaccinated or come through its various waves it remains far from over. One of the hardest-hit parts of the world at the moment is in India, where health services are struggling to maintain adequate oxygen supply such is the demand for it from sick patients.

India’s hacker and maker community have risen to the challenge and done their bit to supply needed resources, and fresh from last year’s PPE manufacturing efforts a group from the Makers Asylum hackerspace in Goa have launched upon a fresh challenge. They aim to start producing the established open-source OxiKit oxygen concentrator in the Indian hackerspace community using locally manufactured parts, and they’ve launched a crowdfunding effort to cover their development, prototyping, and certification work.

The oxygen concentrator project builds on Makers Asylum’s experience last year as part of an extremely successful network of makerspaces producing PPE, which demonstrates that they have the resources, logistics, and ability to take on a project of this size. The OxiKit is no hare-brained contraption but an established and successful design that is already at work, so we believe that this project has a good chance of success. It’s close to home for Hackaday too, and one of the people involved with it is our colleague [Anool Mahidharia].

In a global pandemic only a global response can overcome the incredible challenges before us. For that reason we’d like to urge you to take a look at the Makers Asylum page wherever you are, and if you can, support it.

Continue reading “Indian Makers Respond To The COVID-19 Pandemic By Producing Oxygen Concentrators” →