Repairing A 1955 Classic Radio

We used to say that fixing something was easier than bringing up a design for the first time. After all, the thing you are fixing, presumably, worked at one time or another. These days, that’s not always true as fixing modern gear can be quite a challenge. Watching [Ken’s] repair of an old 1955 Silvertone radio reminded us of a simpler time. You can watch the action on the video below.

If you’ve never had the pleasure of working on an AM radio, you should definitely try it. Some people would use an amplifier to find where the signal dies out. Others will inject a signal into the radio to find where it stops. A good strategy is to start at the volume control and decide if it is before or after that. Then split the apparently bad section roughly in half and test that portion—sort of a hardware binary search. Of course, your first step should probably be to verify power, but after that, the hunt is on.

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Combined Crypto, Anglo-American Style

If you think about military crypto machines, you probably think about the infamous Enigma machine. However, as [Christos T.] reminds us, there were many others and, in particular, the production of a “combined cipher” machine for the US and the UK to use for a variety of purposes.

The story opens in 1941 when ships from the United States and the United Kingdom were crossing the Atlantic together in convoys. The US wanted to use the M-138A and M-209 machines, but the British were unimpressed. They were interested in the M-134C, but it was too secret to share, so they reached a compromise.

Starting with a British Typex, a US Navy officer developed an attachment with additional rotors and converted the Typex into a CCM or Combined Cipher Machine. Two earlier verisons of the attachment worked with the M-134C. However the CSP 1800 (or CCM Mark III) was essentially the same unit made to attach to the Typex. Development cost about $6 million — a huge sum for the middle of last century.

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The Strange Afterlife Of The Xbox Kinect

The tale of the Microsoft Xbox Kinect is one of those sad situations where a great product was used in an application that turned out to be a bit of a flop and was discontinued because of it, despite its usefulness in other areas. This article from the Guardian is a quick read on how this handy depth camera has found other uses in somewhat niche areas, with not a computer game in sight.

It’s rather obvious that a camera that can generate a 3D depth map, in parallel with a 2D reference image, could have many applications beyond gaming, especially in the hands of us hackers. Potential uses include autonomous roving robots, 3D scanning, and complex user interfaces—there are endless possibilities. Artists producing interactive art exhibits would sit firmly in that last category, with the Kinect used in countless installations worldwide.

Apparently, the Kinect also has quite the following in ghost-hunting circles, which as many a dubious TV show would demonstrate, seem almost entirely filmed under IR light conditions. The Kinect’s IR-based structured light system is well-suited for these environments. Since its processing core runs a machine learning application specifically trained to track human figures, it’s no surprise that the device can pick up those invisible, pesky spirits hiding in the noise. Anyway, all of these applications depend on the used-market supply of Kinect devices, over a decade old, that can be found online and in car boot sales, which means one day, the Kinect really will die off, only to be replaced with specialist devices that cost orders of magnitude more to acquire.

In the unlikely event you’ve not encountered non-gaming applications for the Kinect, here’s an old project to scan an entire room to get you started. Just to be perverse, here’s a gaming application that Microsoft didn’t think of, and to round out, the bad news that Microsoft has really has abandoned the product.

Plastic Gear Repair

We’ve seen several methods of repairing plastic gears. After all, a gear is usually the same all the way around, so it is very tempting to duplicate a good part to replace a damaged part. That’s exactly what [repairman 101] does in the video below. He uses hot glue to form a temporary mold and casts a resin replacement in place with a part of a common staple as a metal reinforcement.

The process starts with using a hobby tool to remove even more of the damaged gear, making a V-shaped slot to accept the repair. The next step is to create a mold. To do that, he takes a piece of plastic and uses hot glue to secure it near a good part of the gear. Then, he fills the area with more hot glue and carefully removes it.

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Custom Touchpad PCBs Without The Pain

Many of us use touch pads daily on our laptops, but rarely do we give much thought about what they really do. In fact they are a PCB matrix of conductive pads, with a controller chip addressing it and sensing the area of contact. Such a complex and repetitive pattern can be annoying to create by hand in an EDA package, so [Timonsku] has written a script to take away the work.

It starts with an OpenSCAD script (originally written by Texas Instruments, and released as open source) that creates a diamond grid, which can be edited to the required dimensions and resolution. This is then exported as a DXF file, and the magic begins in a Python script. After adjustment of variables to suit, it finishes with an Eagle-compatible board file which should be importable into other EDA packages.

We’ve never made a touchpad ourselves, but having dome other such repetitive PCB tasks we feel the pain of anyone who has. Looking at this project we’re struck by the thought that its approach could be adapted for other uses, so it’s one to file away for later.

This isn’t the first home-made touchpad project we’ve brought you.

Hackaday Europe 2025 Welcomes David Cuartielles, Announces Friday Night Bring-a-Hack

If you’re coming to Hackaday Europe 2025, you’ve got just over a week to get your bags packed and head on out to Berlin. Of course you have tickets already, right? And if you were still on the fence, let us tempt you with our keynote talk and some news about the Friday night meetup, sponsored by Crowd Supply.

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Hacking Digital Calipers For Automated Measurements And Sorta-Micron Accuracy

We’ll take a guess that most readers have a set of digital calipers somewhere close to hand right now. The cheapest ones tend to be a little unsatisfying in the hand, a bit crusty and crunchy to use. But as [Matthias Wandel] shows us, these budget tools are quite hackable and a lot more precise than they appear to be.

[Matthias] is perhaps best known around these parts for making machine tools using mainly wood. It’s an unconventional material for things like the CNC router he loves to hate, but he makes it work through a combination of clever engineering and a willingness to work within the limits of the machine. To assess those limits, he connected some cheap digital calipers to a Raspberry Pi by hacking the serial interface that seems to be built into all of these tools. His particular calipers output a pair of 24-bit words over a synchronous serial connection a couple of times per second, but at a level too low to be read by the Pi. He solved this with a clever resistor ladder to shift the signals to straddle the 1.8 volt transition on the Pi, and after solving some noise problems with a few strategically placed capacitors and some software debouncing, he was gathering data on his Pi.

Although his setup was fine for the measurements he needed to make, [Matthias] couldn’t help falling down the rabbit hole of trying to milk better resolution from the calipers. On paper, the 24-bit output should provide micron-ish resolution, but sadly, the readings seem to fluctuate rapidly between two levels, making it difficult to obtain an average quickly enough to be useful. Still, it’s a good exercise, and overall, these hacks should prove handy for anyone who wants to dip a toe into automated metrology on a budget.

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