One Man’s Trash… Bicycle Edition

July 30, 2025 by Al Williams 2 Comments

[Remy van Elst] found an obsolete bike navigation system, the Navman Bike 1000, in a thrift store for €10. The device was a rebadged Mio Cyclo 200 from 2015. Can a decade-old GPS be useful? Well, the answer depends on a little reverse engineering.

There were some newer maps available, but they wouldn’t download using the official software. Out comes WireShark and mitmproxy. That allowed [Remy] to eavesdrop on what was going on between the box and its home server. From there he could intercept the downloaded software image, which in turn yielded to scrutiny. There was one executable, but since the device mounted as a drive, he was able to rename that executable and put his own in using the same name.

The device turns out to run Windows CE. It could even run DOOM! Once he was into the box with a file manager, it was fairly straightforward to add newer software and even update the maps using OpenStreetMaps.

This is a great example of how a little ingenuity and open source tools can extend the life of consumer electronics. It isn’t always as easy to find an entry point into some device like this. Then again, sometimes it’s a little easier than maybe it should be.

We’d all but forgotten Windows CE. We see many people using WireShark, but fewer running mitmproxy. It sure is useful.

Supersonic Flight May Finally Return To US Skies

July 24, 2025 by Tom Nardi 51 Comments

After World War II, as early supersonic military aircraft were pushing the boundaries of flight, it seemed like a foregone conclusion that commercial aircraft would eventually fly faster than sound as the technology became better understood and more affordable. Indeed, by the 1960s the United States, Britain, France, and the Soviet Union all had plans to develop commercial transport aircraft capable flight beyond Mach 1 in various stages of development.

Yet today, the few examples of supersonic transport (SST) planes that actually ended up being built are in museums, and flight above Mach 1 is essentially the sole domain of the military. There’s an argument to be made that it’s one of the few areas of technological advancement where the state-of-the-art not only stopped moving forward, but actually slid backwards.

But that might finally be changing, at least in the United States. Both NASA and the private sector have been working towards a new generation of supersonic aircraft that address the key issues that plagued their predecessors, and a recent push by the White House aims to undo the regulatory roadblocks that have been on the books for more than fifty years.

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A photo of a Stirling Engine attached to a bike

Building A Stirling Engine Bike

July 17, 2025 by John Elliot V 27 Comments

Over on his YouTube channel [Tom Stanton] shows us how to build a Stirling Engine for a bike.

A Stirling Engine is a heat engine, powered by the expansion and contraction of a working fluid (such as air) which is heated and cooled in a cycle. In the video [Tom] begins by demonstrating the Stirling Engine with some model engines and explains the role of the displacer piston. His target power output for his bike engine is 150 watts (about 0.2 horsepower) which is enough power to cycle at about 15 mph (about 24 km/h). After considering a CPU heatsink as the cooling system he decided on water cooling instead.

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Smart Coffee Table To Guide Your Commute

July 13, 2025 by Ian Bos 8 Comments

One of the simple pleasures of life is enjoying a drive to work… only to get stuck in traffic that you could’ve known about if you just checked before your daily commute. Who are we kidding? There’s almost nothing worse. [Michael Rechtin] saw this as a great opportunity to spruce up his living room with something practical, a coffee table that serves as a traffic map of Cincinnati.

The table itself is fairly standard with mitered joints at the corners and coated in polyurethane. Bolt on a few legs, and you’ve got a coffee table. But the fun comes with the fancy design on top. A CNC-cut map of Cincinnati is laid out under a sheet of glass. Roads and rivers are painted for a nice touch.

Of course, none of the woodcraft is what gets the attention. This is where the LED light show comes in. On top of the map resides an animated display of either road conditions or the other five pre-programmed animations. The animations include color-coded highways or the good ole’ gamer RGB. To control all of the topographic goodness, a Raspberry Pi is included with some power regulation underneath the table. Every minute, the Pi is able to grab live traffic data from the cloud to display on top.

A looker, this project shows how our hacking fun can be integrated directly into our everyday life in more subtle ways. When we want to decorate ourselves, however, we might want to turn to more personal fare. Check out this miniature liquid simulation pendant for some more everyday design.

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What Will It Take To Restore A Serious Flight Simulator?

July 13, 2025 by Donald Papp 14 Comments

[Jared] managed to find a professional FAA-certified flight simulator at an auction (a disassembled, partial one anyway) and wondered, what would it take to rebuild it into the coolest flight sim rig ever?

In a video, [Jared] gives a tour of the system and highlights the potential as well as pointing out challenges and drawbacks. Fortunately the system is of a modular design overall, and the motion control system is documented. The chassis and physical parts are great, but the avionics stack is a mixed bag with some missing parts and evidence of previous tinkering — that part being not quite so well documented.

Conceptually, a mid-tier gaming rig with a wraparound display will take care of the flight software part, and some custom electronics work (and probably a Raspberry Pi or three) will do for interfacing to various hardware elements. But a lot of details will need to be worked out in order to turn the pile of components into an entertaining flight sim rig, so [Jared] invites anyone who is interested to join him in collaborating on innovative approaches to the myriad little challenges this build presents.

We’ve seen the community pull off some clever things when it comes to flight sims, so we know the expertise is out there.

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DIY Navigation System Floats This Boat

July 10, 2025 by Seth Mabbott 10 Comments

[Tom] has taken a DIY approach to smart sailing with a Raspberry Pi as the back end to the navigation desk on his catamaran, the SeaHorse. Tucked away neatly in a waterproof box with a silicone gasket, he keeps the single board computer safe from circuit-destroying salt water. Keeping a board sealed up so tightly also means that it can get a little too warm. Because of this he under-clocks the CPU so that it generates less heat. This also has the added benefit of saving on power which is always good when you aren’t connected to the grid for long stretches of time.

A pair of obsolescent phones and a repurposed laptop screen provide display surfaces for his navdesk. With these screens he has weather forecasts, maps, GPS, depth, speed over ground — all the data from all the onboard instruments a sailor could want to stream through a boat’s WiFi network — at his fingertips.

There’s much to be done still. Among other things, he’s added a software defined radio to the Pi to integrate radio monitoring into the system, and he’s started experimenting with reprogramming a buoy transmitter, originally designed for tracking fishing nets, so that it can transmit his boat’s location, speed and heading instead.

The software that ties much of this system together is the open source navigational platform OpenCPN which, with its support for third-party plugins, looks like a great choice for experimenting with new gadgets like fishing net buoy transmitters.

For more nautical computing fun check out this open source shipboard computer, and this data-harvesting, Arduino-driven buoy.

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Generatively-Designed Aerospike Test Fired

July 10, 2025 by Navarre Bartz 28 Comments

The aerospike engine holds great promise for spaceflight, but for various reasons, has remained slightly out of reach for decades. But thanks to Leap 71, the technology has moved one step closer to a spacecraft near you with the test fire of their generatively-designed, 3D printed aerospike.

We reported on the original design process of the engine, but at the time it hadn’t been given a chance to burn its liquid oxygen and kerosene fuel. The special sauce was the application of a computational physics model to tackle the complex issue of keeping the engine components cool enough to function while directing 3,500˚C exhaust around the eponymous spike.

Printed via a powder bed process out of CuCrZr, cleaned, heat treated, and then prepped by the University of Sheffield’s Race 2 Space Team, the rocket produced 5,000 Newtons (1,100 lbf) of thrust during its test fire. For comparison, VentureStar, the ill-fated aerospike single stage to orbit project from the 1990s, was projected to produce more than 1,917 kilonewtons (431,000 lbf) from each of its seven RS-2200 engines. Leap 71 obviously has some scaling up to do before this can propel any crewed spacecraft.

If you want to build your own aerospike or 3D printed rocket nozzles we encourage you to read, understand, and follow all relevant safety guidelines when handling your rockets. It is rocket science, after all!