RC Starship Perfects Its Skydiving Routine

December 13, 2020 by Tom Nardi 12 Comments

There’s a good chance you already saw SpaceX’s towering Starship prototype make its impressive twelve kilometer test flight. While the attempt ended with a spectacular fireball, it was still a phenomenal success as it demonstrated a number of concepts that to this point had never been attempted in the real world. Most importantly, the “Belly Flop” maneuver which sees the 50 meter (160 foot) long rocket transition from vertical flight to a horizontal semi-glide using electrically actuated flight surfaces.

Finding himself inspired by this futuristic spacecraft, [Nicholas Rehm] has designed his own radio controlled Starship that’s capable of all the same aerobatic tricks as the real-thing. It swaps the rocket engines for a pair of electric brushless motors, but otherwise, it’s a fairly accurate recreation of SpaceX’s current test program vehicle. As you can see in the video after the break, it’s even able to stick the landing. Well, sometimes anyway.

Just like the real Starship, vectored thrust is used to both stabilize the vehicle during vertical ascent and help transition it into and out of horizontal flight. Of course, there are no rocket nozzles to slew around, so [Nicholas] is using servo-controlled vanes in the bottom of the rocket to divert the airflow from the motors. Servos are also used to control the external control surfaces, which provide stability and a bit of control authority as the vehicle is falling.

As an interesting aside, Internet sleuths looking through pictures of the Starship’s wreckage have noted that SpaceX appears to be actuating the flaps with gearboxes driven by Tesla motors. The vehicle is reportedly using Tesla battery packs as well. So while moving the control surfaces on model aircraft with battery-powered servos might historically have been a compromise to minimize internal complexity, here it’s actually quite close to the real thing.

Unfortunately, the RC Starship made a hard landing of its own on a recent test flight, so [Nicholas] currently has to rebuild the craft before he can continue with further development. We’re confident he’ll get it back in the air, though it will be interesting to see whether or not he’s flying before SpaceX fires off their next prototype.

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Remoticon Video: Learn How To Hack A Car With Amith Reddy

December 10, 2020 by Dan Maloney 14 Comments

There was a time not too long ago when hacking a car more often than not involved literal hacking. Sheet metal was cut, engine cylinders were bored, and crankshafts were machined to increase piston travel. It was all in the pursuit of milking the last ounce performance out of every drop of gasoline, along with a little personal expression in the form of paint and chrome.

While it’s still possible — and encouraged — to hack cars thus, the inclusion of engine control units and other systems to our rides has created an entirely different universe of car hacking options, which Amith Reddy distilled into his very popular workshop at the 2020 Remoticon. The secret sauce behind all the hacks you can accomplish in today’s drive-by-wire cars is the Controller Area Network (CAN), the network used to connect the array of sensors, actuators, and controllers that lie under the metal and plastic of modern cars.

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Hyperloop: Fast, But At What Cost?

December 9, 2020 by Lewin Day 162 Comments

When it comes to travelling long distances, Americans tend to rely on planes, while the Chinese and Europeans love their high speed rail. However, a new technology promises greater speed with lower fares, with fancy pods travelling in large tubes held at near-vacuum pressures. It goes by the name of Hyperloop.

Virgin Hyperloop recently ran the first-ever passenger test of a Hyperloop vehicle, reaching 100 mph on a short test track.

Spawned from an “alpha paper” put together by Elon Musk in 2013, the technology is similar to other vactrain systems proposed in the past. Claiming potential top speeds of up to 760 mph, Hyperloop has been touted as a new high-speed solution for inter city travel, beating planes and high speed rail for travel time. Various groups have sprung up around the world to propose potential routes and develop the technology. Virgin Hyperloop are one of the companies at the forefront, being the first to run a pod on their test track with live human passengers, reaching speeds of 100 mph over a short 500 meter run.

It’s an exciting technology with a futuristic bent, but to hit the big time, it needs to beat out all comers on price and practicality. Let’s take a look at how it breaks down.

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North American Field Guide To Rail Cars

December 9, 2020 by Kristina Panos 53 Comments

Trains are one of the oldest and most reliable ways we have of transporting things and people over long distances. But how often do you think about trains? Where I live, they can clearly be heard every hour or so. I should be used to the sound of them by now, but I like it enough to stop what I’m doing and listen to the whistles almost every time. In the early morning quiet, I can even hear the dull roar as it rumbles down the track.

I recently got a front row seat at a railroad crossing, and as the train chugged through the intersection, I found myself wondering for the hundredth time what all the cars had in them. And then, as I have for the last twenty or thirty years, I wondered why I never see a caboose anymore. I figured it was high time to answer both questions.

Boxcar

Boxcars are probably the most easily identifiable after the engine and the caboose.

Boxcars carry crated and palletized freight like paper, lumber, packaged goods, and even boxes. Refrigerated box cars carry everything from produce to frozen foods.

Boxcars (and barns for that matter) are traditionally a rusty red color because there were few paint options in the late 1800s, and iron-rich dirt-based paint was dirt cheap.

Flat Car

Standard, no-frills flat cars are the oldest types of rail cars. These are just big, flat platform cars that can carry anything from pipe, rail, and steel beams to tractors and military vehicles.

Flat cars come in different lengths and are also made with and without bulkheads that help keep the cargo in place. Some flat cars have a depression in the middle for really tall or heavy loads, like electrical transformers.

Auto Rack

As the name implies, auto racks carry passenger cars, trucks, and SUV from factories to distributors. They come in two- and three-level models, although there have been specialized auto racks over the years.

Perhaps the strangest auto rack of them all was the Vert-a-Pac. When Chevrolet came up with the Vega in the gas-conscious 1970s, they wanted to be able to move them as cheaply as possible, so they shipped the cars on end. If you’re wondering about all the fluids in the car when they were upended, a special baffle kept oil from leaking out, the batteries were capped, and the windshield washer fluid bottle was positioned at an angle.

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Home-Crafting A Motorcycle Throttle Hold

December 8, 2020 by Lewin Day 38 Comments

Cruise control is a common feature on automobiles, though less so in the motorcycle market. Given that continual throttle application on long rides can be a real pain in the wrist, many riders long for such a convenience. As a cheat solution, bolt-on locks that hold the throttle at a set position are available, though quality varies and generally they need to be activated by the throttle hand anyway. [Nixie] wanted a solution that would leave the right hand entirely free, and held, rather than locked, the throttle.

The device [Nixie] came up with is essentially a brake that fits inside the throttle handle and holds it in position. This is achieved with a mechanism that presses a pair of small brake shoes into the inside of the throttle, holding it from rotating back to neutral when the rider lets go. The brake is activated by a control on the left handlebar via a Bowden cable, allowing [Nixie] to activate the throttle hold on the highway and use the right hand to check pockets or simply rest.

It’s a tidy build, and [Nixie] does a great job of explaining the various design choices and the intricacies of the Bowden cable actuated mechanism. It’s anything but a one-size-fits-all build, but other enterprising machinists could certainly duplicate the design for other motorcycles without too many problems.

For those interested in more traditional cruise control, we’ve featured a teardown of a simplistic 90s Jeep system before. Video after the break.

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Exploring Turn Of The Century RAF Avionics

December 1, 2020 by Tom Nardi 25 Comments

The second hand market is a wonderful thing; you never know what you might find selling for pennies on the dollar simply because it’s a few years behind the curve. You might even be able to scrounge up some electronics pulled out of a military aircraft during its last refit. That seems to be how [Adrian Smith] got his hands on a Control Display Unit (CDU) originally installed in a Royal Air Force AgustaWestland AW101 “Merlin” helicopter. Not content to just toss it up on a shelf, he decided to take a look inside of the heavy-duty cockpit module and see if he couldn’t make some sense out of how it works.

Unsurprisingly, [Adrian] wasn’t able to find much information on this device on the public Internet. The military are kind of funny like that. But a close look at the burn-in on the CDU’s orange-on-black plasma display seems to indicate it had something to do with the helicopter’s communication systems. Interestingly, even if the device isn’t strictly functional when outside of the aircraft, it does have a pretty comprehensive self-test and diagnostic system on-board. As you can see in the video after the break, there were several menus and test functions he was able to mess around with once it was powered up on the bench.

With the case cracked open, [Adrian] found three separate PCBs in addition to the display and keyboard panel on the face of the CDU. The first board is likely responsible for communicating with the helicopter’s internal systems, as it features a MIL-STD-1553B interface module, UART chips, and several RS-232/RS-485 transceivers. The second PCB has a 32-bit AMD microcontroller and appears to serve as the keyboard and display controller, possibly also providing the on-board user interface. The last board looks to be the brains of the operation, with a 25 MHz Motorola 68EC020 CPU and 1Mb of flash.

All of the hardware inside the CDU is pretty generic, but that’s probably the point. [Adrian] theorizes that the device serves as something of a generic pilot interface module, and when installed in the Merlin, could take on various functions based on whatever software was loaded onto it. He’s found pictures online that seem to show as many as three identical CDUs in the cockpit, all presumably running a different system.

[Adrian] has uncovered some interesting diagnostic information being dumped to the CDU’s rear connectors, but he’s still a long way off from actually putting the device to any sort of practical use. If any Hackaday readers have some inside information on this sort of hardware, we’re sure like to hear about it.

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Electric BMX With Friction Drive

November 26, 2020 by Bryan Cockfield 9 Comments

Electric bikes have increased in popularity dramatically over the past few years, and while you can easily buy one from a reputable bicycle manufacturer, most of us around here might be inclined to at least buy a kit and strap it to a bike we already have. There aren’t kits available for every bike geometry, though, so if you want an electric BMX bike you might want to try out something custom like [Shea Nyquist] did with his latest build. (Video, embedded below.)

BMX frames have a smaller front triangle than most bikes, so his build needed to be extremely compact. To that end, it uses two small-sized motors connected together with a belt, which together power a friction drive which clamps against the rear tire to spin it directly. This keeps the weight distribution of the bike more balanced as well when compared to a hub drive, where the motor is installed in the rear wheel. It also uses a more compact lithium polymer battery pack instead of the typical 18650 lithium ion packs most e-bikes use, and although it only has a range of around three miles it’s more than enough charge to propel it around a skate park.

The build boasts impressive numbers too, at 2.5 kW peak power per motor. This puts it in electric motorcycle territory, and it’s indeed fast despite its small stature. For a true high speed e-bike experience, though, you’ll need a slightly larger frame and motor even if it means tossing safety out of the window. Continue reading “Electric BMX With Friction Drive” →