Honor Your Hacker Heroes

September 24, 2022 by Elliot Williams 3 Comments

We recently ran an article on a sweet percussion device made by minimal-hardware-synth-madman [Gijs Gieskes]. Basically, it amplifies up an analog meter movement and plays it by slamming it into the end stops. Rhythmically, and in stereo. It’s got that lovely thud, plus the ringing of the springs. It takes what is normally a sign that something’s horribly wrong and makes a soundtrack out of it. I love it.

[Gijs] has been making electro-mechanical musical hacks for about as long as I’ve been reading Hackaday, if not longer. We’ve written up no fewer than 22 of his projects, and the first one on record is from 2005: an LSDJ-based hardware sequencer. All of his projects are simple, but each one has a tremendously clever idea at its core that comes from a deep appreciation of everything going on around us. Have you noticed that VU meters make a particular twang when they hit the walls? Sure you have. Have you built a percussion instrument out of it? [Gijs] has!

Maybe it’s a small realization, and it’s not going to change the world by itself, but I’ve rebuilt more than a couple projects from [Gijs]’ repertoire, and each one has made my life more fun. And if you’re a regular Hackaday reader, you’ve probably seen hundreds or thousands of similar little awesome ideas played out, and maybe even taken some of them on as your own as well. When they accumulate up, I believe they can change the world, at least in the sense of filling up a geek’s life. I hope that feeling comes across when we write up a project. Those of you out there hacking, we salute you!

This Scratch-Built X-Ray Tube Really Shines

September 24, 2022 by Dan Maloney 25 Comments

On no planet is making your own X-ray tube a good idea. But that doesn’t mean we’re not going to talk about it, because it’s pretty darn cool.

And when we say making an X-ray tube, we mean it — [atominik] worked from raw materials, like glass test tubes, tungsten welding electrodes, and bits of scrap metal, to make this dangerously delightful tube. His tool setup was minimalistic as well– where we might expect to see a glassblower’s lathe like the ones used by [Dalibor Farny] to make his custom Nixie tubes, [atominik] only had a small oxy-propane hand torch to work with. The only other specialized tools, besides the obvious vacuum pump, was a homebrew spot welder, which was used to bond metal components to the tungsten wires used for the glass-to-metal seals.

Although [atominik] made several versions, the best tube is a hot cathode design, with a thoriated tungsten cathode inside a copper focusing cup. Across from that is the anode, a copper slug target with an angled face to direct the X-rays perpendicular to the long axis of the tube. He also included a titanium electrode to create a getter to scavenge oxygen and nitrogen and improve the vacuum inside the tube. All in all, it looks pretty similar to a commercial dental X-ray tube.

The demonstration in the video below is both convincing and terrifying. He doesn’t mention the voltage he’s using across the anode, but from the cracking sound we’d guess somewhere around 25- to 30 kilovolts. The tube really gets his Geiger counter clicking.

Here’s hoping [atominik] is taking the proper precautions during these experiments, and that you do too if you decide to replicate this. You’ll also probably want to check out our look at the engineering inside commercial medical X-ray tubes.

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Chandelier Mimics The Solar Analemma

September 24, 2022 by Lewin Day 14 Comments

The solar analemma is the shape the sun traces out when photographed each day at the same time and same location for a whole year – but you probably knew that already. [makendo] decided to use this skewed figure-eight shape as the inspiration for a chandelier, and the results are stunning.

A laser cutter was used to cut out segments of the analemma shape in plywood, such that they could slot together into the full form. These were then glued together on to a plywood sheet as a template to cut out the full-size form in a single piece. Some laminate edging was then added and the entire thing was given a coat of black gloss paint. String lights were cut up to provide the many globe fittings required, and installed on the back of the chandelier.

[makendo] notes that with a full 51 bulbs in the chandelier, it’s way too bright for most dining room settings. A dimmer is thus used to tone down the output to reduce eyestrain at mealtimes. It’s a fun build, and we’ve always loved light fixtures that are inspired by astronomy. If you like the moon more than the sun, though, there’s a build for you too!

A Spreadsheet For The Python Hacker

September 23, 2022 by Al Williams 9 Comments

You can write a Python program or use a Jupyter Notebook to do almost anything. But you can also get a lot of things done quickly using a spreadsheet. Grist is a “hacker’s” spreadsheet that merges these worlds. It looks like a spreadsheet, but underneath are SQLite tables and the formula language is Python.

The code is open source and if you want it hosted, there are free and paid plans. You can even try it out without even logging in and either start with a blank screen or use a template. You can see an introductory video below.

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Simple Stopwatch with two buttons, an eight digit 7-segment display and ICSP programming cable going into the board

Add An OSHW Certified Stopwatch To Your Toolkit

September 23, 2022 by Abe Connelly 5 Comments

[MakingDevices] has created a simple stopwatch that makes for a nice introduction to surface mount electronic design and assembly. The project is open source hardware (OSHW) certified, with Gerbers, KiCAD files, and software all available.

Conceptually the stopwatch is straight forward, with a row of two four digit seven-segment displays being driven by a PIC18LF14k50 microcontroller through multiple NPN transistors. The PIC doesn’t quite have enough data lines to drive the two displays at once so an inverter is used to toggle between the two seven-segment blocks.

The circuit is continuously powered from a CR2032 coin cell battery. For normal usage with display, [MakingDevices] estimates 30+ hours of operation and 140+ hours without display, but still counting time. When idle, the “Extreme Low-Power (XLP)” capabilities of the PIC put the operating window estimates well beyond the self discharge of the coin cell battery. There’s an in circuit serial programming (ICSP) footprint that accepts a pogo pin TC2030-MCP-NL adapter for flashing the PIC.

Don’t let the simplicity fool you, this is a well documented project with detailed posts about the design, simulation and battery consumption. Various videos and glamour shots give a whole picture of the process, from design, assembly, testing to final validation.

It’d be wonderful to see the project extended or hacked on further, perhaps with a cute enclosure or case.

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For The ESP’s Next ESP Trick…

September 23, 2022 by Al Williams 10 Comments

It is a pretty stale dad joke to tell someone you have ESP when you mean you have an ESP8266 or ESP32 in your hand. However, [Naufil Metkar] uses an ESP device to pretend — via a magic trick — that he does have ESP. The trick requires a bit of 3D printing, an MPU6050 gyro sensor, and a lot of showmanship.

We hate to spoil an illusion, but you can probably figure it out from the list of things you need. The die has a gyro in it and uses a small ESP module to transmit its current orientation out to a display. There is a small reed switch that lets you turn off the device with a magnet. Without it, the battery dies quickly.

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Filament Cutter Uses Unusual (But Effective) 3D-Printed Spring Design

September 23, 2022 by Donald Papp 12 Comments

When one needs a spring, a 3D-printed version is maybe not one’s first choice. It might even be fair to say that printed springs are something one ends up making, rather than something one sets out to use. That might change once you try the spring design in [the_ress]’s 3D-printed filament cutter with printed springs.

The filament cutter works like this: filament is inserted into the device through one of the pairs of holes at the bottom. To cut the filment, one presses down on the plunger. This pushes a blade down to neatly cut the filament at an angle. The cutter is the device’s only non-printed part; a single segment from an 18 mm utility knife blade.

The springs are of particular interest, and don’t look quite like a typical spring. They take their design from this compliant linear motion mechanism documented on reprap.org, and resemble little parallel 4-bar linkages. These springs have limited travel, but are definitely springy enough for the job they need to do, and that’s the important part.

Want a more traditional coiled spring? Annealing filament wound around a mandrel can yield useful results, and don’t forget the fantastic mechanisms known as flexures; they have clear similarities to the springs [the_ress] used. You can see her design in action in the short video, embedded below.

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