If someone tells you they have seen a rotary engine, the chances are that you will immediately think of a Wankel engine, as you might find in some of the more exotic Mazda sports cars. But there is another rotary engine that has a prior claim to the name, and it can be found as the power unit for many early-twentieth-century aircraft. In these rotary engines the cylinders are arranged radially around a stationary crankshaft, and it is the engine itself that rotates. They have the advantage of extreme simplicity, smooth power, and a low parts count, at the expense of total loss lubrication, a relatively large rotating mass, and some difficulty in controlling their power. These rotary engines were largely obsolete by the 1920s, but recent upsurge of interest in WW1-era aircraft has led to the creation of a small demand for them. New Zealand based Classic Aero Machining Service have stepped in to fill that gap and are remanufacturing the Gnome radial engine, the most numerous design of that era.
For anyone with an interest in internal combustion engines, the Gnome is a fascinating study. It’s a nine-cylinder design that runs a four-stroke Otto cycle, but instead of the two or more valves you might be familiar with from your motor vehicle it has only a single valve. The so-called Monosoupape design uses its valve for both fuel and exhaust, opening it on the inlet stroke as well as the exhaust stroke. The simplicity of a single valve and no carburetor is thus offset by a difficulty in varying its power , so rotary engines would frequently reduce the number of firing cylinders in lieu of throttling back.
The CAMS Gnome is a faithful copy of the original, but with modern metallurgy and the addition of an electronic ignition system. The original castor oil is still used — it seems classic aviation buffs like the smell — but becuase it is notorious for leaving sticky deposits in the engine they are evaluating modern alternatives. They have some technical details on their website, and there’s a good chance you my hear one of their engines one day at an air show near you.
Continue reading “Remanufacturing A Rotary Airplane Engine”
The 2019 Geneva International Motor Show has a number of “concept” vehicles. These are vehicles that usually include some cool feature that isn’t really practical — at least today. For example, in the past, concept cars have had adjustable color interior lighting, plug-in hybrid engines, and power windows — all things that would eventually become commonly available. However, today’s advances in computer-generated graphics have meant you can show things you can’t begin to build. Case in point: Goodyear has a video touting the Aero — a solid car tire that doubles as a propeller for your garden variety flying car.
To us, the thing looks more like a science fiction movie trailer than anything remotely practical. Four relatively small wheels with no central hub can flip and provide enough lift to propel a sizeable vehicle skyward. Even more interesting, is to transition modes from ground to flight, the vehicle balances on two wheels while using only two as propellers to generate lift.
Continue reading “Goodyear Aero Thinks Flying Cars are a Thing”
[Adam Zeloof] (legally) obtained a retired electric scooter and documented how it worked and how he got it working again. The scooter had a past life as a pay-to-ride electric vehicle and “$1 TO START” is still visible on the grip tape. It could be paid for and unlocked with a smartphone app, but [Adam] wasn’t interested in doing that just to ride his new scooter.
His report includes lots of teardown photos, as well as a rundown of how the whole thing works. Most of the important parts are in the steering column and handlebars. These house the battery, electronic speed controller (ESC), and charging circuitry. The green box attached to the front houses a board that [Adam] determined runs Android and is responsible for network connectivity over the cellular network.
To get the scooter running again, [Adam] and his brother [Sam] considered reverse-engineering the communications between the network box and the scooter’s controller, but in the end opted to simply replace the necessary parts with ones under their direct control. One ESC, charger, and cheap battery monitor later the scooter had all it needed to ride again. With parts for a wide variety of electric scooters readily available online, there was really no need to reverse-engineer anything.
Ridesharing scooter startups are busy working out engineering and security questions like how best to turn electric scooters into a) IoT-connected devices, and b) a viable business plan. Hardware gets revised, and as [Adam] shows, retired units can be pressed into private service with just a little work.
The motors in these things are housed within the wheels, and have frankly outstanding price-to-torque ratios. We’ve seen them mated to open-source controllers and explored for use in robotics.
A Jeep is fun offroad, a motorcycle perhaps even more so. Diehard renegades go even further and get about in Unimogs and on snowmobiles. [amazingdiyprojects] might just have topped them all however, with his latest project – the astonishing Inflatable Car.
Despite the name, it’s a vehicle that defies clear definition. Consisting of a lightweight aluminium frame and exposed seat, the construction is almost 100% hacked. PVC fabric is used with advanced adhesive tapes to create inflatable wheels that are 2 meters in diameter. Vacuum cleaners are used to inflate the massive tyres, with custom 3D printed valves to ensure even inflation. Drive is courtesy of four handheld concrete mixers, repurposed for their torquey motors and robust geartrains. Even the user interface is a triumph of found parts – consisting of former cordless drills, used for their PWM hardware and covered in extra switches.
Looking like a moon lander from a strange 1950s version of the future, the machine is impressively nimble for its size. Episode 1 starts with a single wheel hooked up to the inflation gear and a single drive motor. Just a few short months later, episode 7 has the prototype machine crawling out from the confines of the back garden and out into the street. The machine is already impressively fast and capable, and we can’t wait to see what happens next.
It’s a build that is truly impressive in its scale, though we’ve come to expect no less from [amazingdiyprojects]. Video after the break.
Continue reading “A Big, Mean, Inflated Machine”
At the turn of the 21st century, it became pretty clear that even our cars wouldn’t escape the Digital Revolution. Years before anyone even uttered the term “smartphone”, it seemed obvious that automobiles would not only become increasingly computer-laden, but they’d need a way to communicate with each other and the world around them. After all, the potential gains would be enormous. Imagine if all the cars on the road could tell what their peers were doing?
Forget about rear-end collisions; a car slamming on the brakes would broadcast its intention to stop and trigger a response in the vehicle behind it before the human occupants even realized what was happening. On the highway, vehicles could synchronize their cruise control systems, creating “flocks” of cars that moved in unison and maintained a safe distance from each other. You’d never need to stop to pay a toll, as your vehicle’s computer would communicate with the toll booth and deduct the money directly from your bank account. All of this, and more, would one day be possible. But only if a special low-latency vehicle to vehicle communication protocol could be developed, and only if it was mandated that all new cars integrate the technology.
Except of course, that never happened. While modern cars are brimming with sensors and computing power just as predicted, they operate in isolation from the other vehicles on the road. Despite this, a well-equipped car rolling off the lot today is capable of all the tricks promised to us by car magazines circa 1998, and some that even the most breathless of publications would have considered too fantastic to publish. Faced with the challenge of building increasingly “smart” vehicles, manufacturers developed their own individual approaches that don’t rely on an omnipresent vehicle to vehicle communication network. The automotive industry has embraced technology like radar, LiDAR, and computer vision, things which back in the 1990s would have been tantamount to saying cars in the future would avoid traffic jams by simply flying over them.
In light of all these advancements, you might be surprised to find that the seemingly antiquated concept of vehicle to vehicle communication originally proposed decades ago hasn’t gone the way of the cassette tape. There’s still a push to implement Dedicated Short-Range Communications (DSRC), a WiFi-derived protocol designed specifically for automotive applications which at this point has been a work in progress for over 20 years. Supporters believe DSRC still holds promise for reducing accidents, but opponents believe it’s a technology which has been superseded by more capable systems. To complicate matters, a valuable section of the radio spectrum reserved for DSRC by the Federal Communications Commission all the way back in 1999 still remains all but unused. So what exactly does DSRC offer, and do we really still need it as we approach the era of “self-driving” cars?
Continue reading “When Will Our Cars Finally Speak the Same Language? DSRC for Vehicles”
Now that nearly every car on the road comes with an electronic key fob, people are desperate to find ways to repair these indispensable little gadgets without coughing up potentially hundreds of dollars at the dealership. There’s a whole market for replacement shells which you can transplant your (hopefully) still functional electronics into, but if you’re going to go through the trouble of putting the electronics into a new case, why not make it special?
That’s what [Michicanery] was thinking when he decided to build his own custom key fob. The end result is an utterly magnificent feat of engineering that’s sure to be a conversation for the life of the vehicle, if not beyond. Made of wood and aluminum cut on his OpenBuilds Lead CNC 1010, this build just might inspire you to “accidentally” drop your existing fob from a great height. Oh no, what a shame.
[Michicanery] starts by disassembling his original fob, which is the type that has a key integrated directly into the device. This meant his replacement would need a bit more thought put into it than a separate stand-alone fob, but at least it wasn’t one of the ones where you have to stick the whole thing into the dashboard. To make sure the build was strong enough to survive a lifetime of being turned in the ignition and generally fiddled with, he cut the central frame and buttons out of 1/4″ thick aluminum.
The top and bottom of the fob were then cut from Chechen wood and then chamfered on a table router so it felt a bit better in the hand. He applied oil to the pieces to bring out the natural color and grain of the wood, but not before engraving his own logo onto the back of the case for that extra touch of personalization. Not that we think [Michicanery] is going to have trouble identifying his keys from this point on.
Like the incredible watch cases we’ve seen recently, this is a perfect example of an everyday object getting a new lease on life as a bespoke creation thanks to a custom built enclosure. Granted we’re not sure Honda key fobs have quite the heirloom potential of a good watch, but we’d still prefer it over the black plastic original.
Follow this train of thought: cars have sensors, cars are in frequent use over large areas, cars are the ultimate distributed sensor network for weather conditions.
Many years ago, as I wasted yet another chunk of my life sitting in the linear parking lot that was my morning commute, I mused that there had to be a way to prevent this madness. I thought: What if there was a way for the cars to tell each other where slowdowns are? This was long before smartphones, so it would have to be done the hard way. I imagined that each vehicle could have a small GPS receiver and a wireless transceiver of some sort, to send the vehicle’s current position to a central server, which would then send the aggregate speed data for each road back to the subscriber’s car. A small display would show you the hotspots and allow you to choose an alternate route. Genius! I had finally found my billion dollar idea.
Sadly, it was not to be. Seemingly days later, everyone on the planet had a GPS-equipped smartphone in his or her pocket, and the complex system I imagined was now easily implemented as software. Comically, one of the reasons I chose not to pursue my idea is that I didn’t think anyone would willingly let a company have access to their location information. Little did I know.
So it was with great interest that I read an article claiming that windshield wiper data from connected cars can be used to prevent floods. I honestly thought it was a joke at first, like something from a Monty Python sketch. But as I read through the article, I thought about that long-ago idea I had had, which amounted to a distributed sensor platform, might actually be useful for more than just detecting traffic jams.
Continue reading “Predicting Weather with the Internet of Cars”