Building A 3D Printed Scanning Tunneling Microscope

September 30, 2024 by Dave Rowntree 11 Comments

YouTuber [MechnicalRedPanda] has recreated a DIY STM hack we covered about ten years ago, updating it to be primarily 3D-printed, using modern electronics, making it much more accessible to many folks. This simple STM setup utilises a piezoelectric actuator constructed by deliberately cutting a piezo speaker into four quadrants. With individual drive wires attached to the four quadrants. [MechPanda] (re)discovered that piezoelectric ceramic materials are not big fans of soldering heat. Still, in the absence of ultrasonic welding equipment, he did manage to get some wires to take to the surface using low-temperature solder paste.

As you can tell, you can only image conductive samples

A makeshift probe holder was glued on the rear side of the speaker actuator, which was intended to take a super sharp needle-like piece of tungsten wire. Putting the wire in tension and cutting at a sharp angle makes it possible with many attempts to get some usable points. Usable, in this instance, means sharp down the atomic level. The sample platform, actuator mount and all the connecting parts are 3D-printed with PA-CF. This is necessary to achieve enough mechanical stability with normal room temperature fluctuations. Three precision screws are used to level the two platforms in a typical kinematic mount structure, which looks like the only hard-to-source component. A geared stepper motor attached to the probe platform is set up to allow the probe to be carefully advanced towards the sample surface. Continue reading “Building A 3D Printed Scanning Tunneling Microscope” →

Internet Connected TI-84 To Cut Your Academic Career Short

September 29, 2024 by Danie Conradie 22 Comments

In an educational project with ethically questionable applications, [ChromaLock] has converted the ubiquitous TI-84 calculator into the ultimate cheating device.

The foundation of this hack lies in the TI-84’s link protocol, which has been a mainstay in calculator mods for years. [ChromaLock] uses this interface to connect to a tiny WiFi-enabled XIAO ESP32-C3 module hidden in the calculator. It’s mounted on a custom PCB with a simple MOSFET-based level shifting circuit, and slots neatly into a space on the calculator rear cover. The connecting wires are soldered directly to the pads of the 2.5 mm jack, and to the battery connections for power.

But what does this mod do? It connects your calculator to the internet and gives you a launcher with several applets. These allow you to view images badly pixelated images on the TI-84’s screen, text-chat with an accomplice, install more apps or notes, or hit up ChatGPT for some potentially hallucinated answers. Inputting long sections of text on the calculator’s keypad is a time-consuming process, so [ChromaLock] teased a camera integration, which will probably make use of newer LLMs image input capabilities. The ESP32 doesn’t handle all the heavy lifting, and needs to connect to an external server for more complex interfaces.

To prevent pre-installed programs from being used for cheating on TI-84s, examiners will often wipe the memory or put it into test mode. This mod can circumvent both. Pre-installed programs are not required on the calculator to interface with the hardware module, and installing the launcher is done by sending two variables containing a password and download command to the ESP32 module. The response from the module will also automatically break the calculator out of test mode.

We cannot help but admire [ChromaLock]’s ingenuity and polished implementation, and hopefully our readers are more interested in technical details than academic self-sabotage. For those who need even more capability in their calculator, we’d suggest checking out the NumWorks. Continue reading “Internet Connected TI-84 To Cut Your Academic Career Short” →

Spectroscopy On The Cheap

September 27, 2024 by Al Williams 11 Comments

[Project 326] wanted to know exactly what gas was in some glass tubes. The answer, of course, is to use a spectrometer, but that’s an expensive piece of gear, right? Not really. Sure, these cheap devices aren’t perfect, but they are serviceable and, as the video below shows, there are ways to work around some of the limitations.

The two units in question are “The Little Garden” spectrometer and a TLM-2. Neither are especially sensitive, but both are well under $100, so you can’t expect much. Because the spectrometers were not very sensitive, a 3D printed jig and lens were used to collect more light and block ambient light interference. The jigs also allowed the inclusion of special filters, which enhanced performance quite a bit. The neon bulbs give off the greatest glow when exposed to high voltage. Other bulbs contain things like helium, xenon, and carbon dioxide. There were also tubes with mercury vapor and even deuterium.

We’ll admit it. Not everyone needs a spectrometer, but if you do, there’s a lot of really interesting info on how to get the most out of these cheap devices. Apparently, [Project 326] was frustrated that he couldn’t buy an X-ray spectrometer and has vowed to create one, so we’ll be interested to see how that goes.

Some homebrew spectrometers can get pretty fancy. Of course, there’s more to spectroscopy than just optics.

Continue reading “Spectroscopy On The Cheap” →

A DaVinci Screw-Cutting Machine

September 25, 2024 by Dave Rowntree 5 Comments

It’s not news that Leonardo DaVinci was somewhat ahead of his time, and over the centuries many of the creations in his sketchbooks have been created and proved quite functional. The guys from the YouTube channel How To Make Everything have been looking at one such sketch, a screw thread-cutting machine. At first glance, it seems a little flawed. Threads are hard to make by hand, and you can see that this thread-cutting machine needs two identical threads operating as a reference to make it work. However, as the guys demonstrate, you can create threads by hand using simple methods.

Starting with an offset blade mounted on a block with a hole through it, a dowel can be scribed with a starter thread. This can then be worked by hand to cut enough of a groove for the application. They demonstrated that the machine was viable using nothing but wood for construction. A metal blade was mounted, and some preload force was applied to it with a spring. The dowel to be cut was loaded, and the machine ran back and forth enough times to create a very nice-looking screw thread. And once you’ve made two identical threaded dowels, you can use them to upgrade the machine or even build a second. Once you have a repeatable way to make such threads, all kinds of applications become more accessible. Need a bench vice? No problem now!

Whilst the demonstration doesn’t precisely follow the plans laid out by the master inventor, they aren’t all that clear on the cutting tool after all, it’s nice to see people still wanting to build his ideas, and we’ll certainly be following along.

If you like these “from scratch” builds, you’ll like this other one. Leonardo’s work wasn’t just about machines; he was also very interested in science. Here’s a recreation of his demonstration of gravity as a form of acceleration.

Continue reading “A DaVinci Screw-Cutting Machine” →

ESP32 Powers Custom Darkroom Timer

September 24, 2024 by Tom Nardi 4 Comments

Developing your own film is an unabashedly analog process, which is one of the reasons people still gravitate towards it. After spending all day pushing buttons and looking at digital displays, spending some quiet time in the dark with pieces of paper and chemicals can be a way to decompress. But that doesn’t mean there isn’t room for a bit of modern digital convenience.

Specifically, [John Jones] wanted a timer that offered more features than his old school analog model, so he decided to build one himself. He took the long away around to make sure the end result would be a tool he could rely on, which meant getting a custom PCB made, 3D printing a case to fit in with his existing workspace, and designing a control panel that he could operate in the dark.

The PCB plays host to an ESP32 development board and an I/O expander that connects up to the array of LEDs, switches, and buttons on the front panel. The bottom-half of of the 3D printed enclosure is pretty simple, but the control panel is quite a piece of work.

Borrowing a trick from the flight sim community, [John] switched over to a clear filament after laying down the first few layers of the panel. This essentially created an integrated light diffuser, and with the addition of a few red LEDs, he had very slick backlit labels on his panel with relatively minimal effort.

We’ve covered custom darkroom tools in the past, from this relatively simple enlarger to an automated system that will develop the film for you.

Continue reading “ESP32 Powers Custom Darkroom Timer” →

Find My Power Tool Battery

September 23, 2024 by Jenny List 7 Comments

Apple’s Find My network has seen its fair of hacks to devices, but perhaps the most unusual we’ve seen is before us today. [biemster] has added a Lidl Parkside smart connected power tool battery to the network, not by concealing an AirTag within it, but by hacking its on-board firmware.

Opening up the device reveals a Tuya BT17L Bluetooth module, the hackable nature of which due to other projects prompted a port of a previous Find My project which provided open source access to the network. The result is as he describes, the world’s chunkiest key finder, and also we’re guessing the one with one of the longest battery lives too.

The European budget supermarkets are well known for their budget bargain aisles, and Lidl’s Parkside range has some surprisingly robust tools among it. They might not quite be up to replacing IKEA in the hacker source stakes, but those of us who live in countries served by them know to keep an eye out in the hope of fresh gems alongside those awesome AlpenFest apple crumble cakes. This one certainly isn’t the first Parkside hack we’ve seen.

The Tiny Toolkit Manifesto

September 22, 2024 by Jenny List 47 Comments

Most of us have some form of an on-the-go toolkit, but how much thought have we put into its contents? There’s a community of people who put a lot of thought into this subject, and EMF Camp have put up one of their talks from earlier in the summer in which [Drew Batchelor] sets out their manifesto and introduces tinytoolk.it, a fascinating resource.

The talk is well worth a watch, as rather than setting the tools you should be carrying, it instead examines the motivations for your kit in the first place, and how to cull those which don’t make the grade. If an item seems to see little use, put a piece of tape with the date on it every time it comes out, to put a number on it. As an example he ended up culling a multi-tool from his kit, not because it’s not an extremely useful tool, but because he found everything it did was better done by other items in the kit.

It’s probable we’ll all look at our carry-around kit with new eyes after watching this, it’s certain that ours could use a few tweaks. What’s in your kit, and how could you improve it? Let us know in the comments.

Continue reading “The Tiny Toolkit Manifesto” →