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.
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.
[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.
[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.
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!
Modern RC cars can be pretty darn fast. That’s fun and all, but it also makes it easy to crash them into things. This problem inspired [Narrow Studios] to whip up something to offer a bit of protection.
The concept is simple enough—the RC car just needs some way to detect obstacles and stop before hitting them. The build relies on ultrasonic sensors as rangefinders to spot solid objects in the path of the vehicle. An Arduino Nano is in charge of reading the sensors. When it appears the car is approaching a wall or similar obstacle, it fires off a PWM signal to the car’s motor controller commanding it to brake. The additional hardware is held to the car with a bunch of custom printed brackets.
The setup isn’t perfect; the video notes that if you insist on accelerating quickly when close to a wall, you still have a fair chance of hitting it. That’s largely put down to the refresh time of the sensors and the overall system, which could be improved with further work. Still, if you’re always crashing your RC car into walls or curbs, this kind of thing might appeal to you.
The last interesting thing to happen in Donald, BC was when it burned down in the 1910s.
Well, they’ve thankfully moved out of the tent in their parents’ back yard where the prototype was built. They’ve bought themselves a company town: Donald, British Columbia, complete with a totally-not-controversial slogan “Make Donald Great Again”.
More interesting is that their commercial-off-the-shelf (COTS), right-to-repair centered approach isn’t just for semi-trucks: they’re now a certified OEM manufacturer of a rolling heavy truck chassis you can put your truck cab or RV body on, and they have partnered with three coach-builders for RVs and a goodly number of manufacturing partners for truck conversion kits. The kits were always in the plan, but selling the rolling chassis is new.
One amazingly honest take-away from the video is the lack of numbers for the pickups: top speed, shaft horsepower, torque? They know what all that should be, but unlike the typical vaporware startup, Edison won’t tell you the engineering numbers on the pickup truck kits until it has hit the race track and proved itself in the real world. These guys are gear-heads first and engineers second, so for once in a long time the adage “engineers hate mechanics” might not apply to a new vehicle.
The dirt track is the first thing under construction in Donald, so hopefully the next update we hear from Edison Motors will include those hard numbers, including pesky little things like MSRP and delivery dates. Stay tuned.
In our last post about an electric truck, a lot of you in the comments wanted something bigger, heavier duty, not pure battery, and made outside the USA. Well, here it is.
