3D Printing A New Kind Of Skateboard That Is Ultimately Unsafe

Skateboards were organically developed in the 1940s and 1950s; 30 years would then pass before the ollie was developed, unlocking new realms for skaters dedicated to the artform. The advent of powerful batteries and motors would later make the electric skateboard a practical and (un?)fashionable method of transport in more recent years. Now, [Ivan Miranda] is pushing the cutting edge of skateboarding even further, with an entirely weird build of his own design.

The build was inspired by one-wheels, which [Ivan] considers fun but ultimately too dangerous. Most specifically, he fears crashing when the one-wheel is tilted beyond a critical angle at which the motor can restore it to a level  heading. His concept was to thus create a two-wheeled board that is nonetheless controlled with the leaning interface of a one-wheel.

The frame is assembled from a combination of 3D-printed brackets and aluminium extrusion. The rider stands on a platform which rides on rollers on top of the frame, tilting it to control the drive direction of the board. Detecting the angle is handled by an Arduino Due with an MPU6050 IMU onboard. The microcontroller is then responsible for commanding the speed controller to move the board. Drive is from a brushless DC motor, hooked up to one of the wheels via a toothed belt. Power is courtesy of three power tool batteries.

Early testing showed the design to be a bit of a death trap. However, with refinement to the control system code and an improved battery setup, it became slightly more graceful to ride. [Ivan] notes that more tuning and refinement is needed to make the thing safer than a one-wheel, which was the original goal. We’ve seen some other great builds from [Ivan] before, too. Video after the break.

Continue reading “3D Printing A New Kind Of Skateboard That Is Ultimately Unsafe”

Building A One Wheel With Tracks

One-wheels use motion-tracking hardware and fine motor control to let you balance on a single wheel. That’s neat and all, but [Michael Rechtin] had another idea in mind—what if a one-wheel used a track instead?

The idea behind the track was to make the one-wheel more capable on surfaces where wheels simply can’t compete. The tracked drivetrain was largely 3D printed, including some massive gears that are supplemented by a big old 150 mm ball bearing which sits around the drive motor itself. If you love planetary gear trains with a 4:1 reduction, this project is for you. Carbon-fiber reinforced filament was used for many of the parts to give them some additional strength. Control is a little different than a traditional one-wheel, since the flat-bottomed track means lean controls won’t work. Instead, a wireless hand throttle was constructed to enable the rider to command the direction of travel.

It’s not easy to ride, but the one-track does actually work. It’s capable of crawling its way around on grass and snow quite well. There were some issues with the printed tracks and rollers, particularly when turning, but tweaks to round out the track profile helped solve that issue to a degree. There’s a reason we often use wheels instead of tracks, but somehow tracks are still just cool.

Continue reading “Building A One Wheel With Tracks”

A man in a dark shirt stands at a podium in front of a projector screen with the text "50% OF US CAR TRIPS" in white above yellow text saying "1 HUMAN < 3 MILES". The screen is flanked by decor saying "Supercon" in white on a black background.

Supercon 2022: Bradley Gawthrop Wants You To Join The PEV Revolution

During the 20th Century, much of the western world decided that motor vehicles were the only desirable form of transportation. We built our cities to accommodate cars through parking, stop lights, and any number of other infrastructure investments so that you could go get milk and bread in style. In the US, 50% of automobile trips are less than three miles and have only one occupant. [Bradley Gawthrop] asked if there might be a more efficient way to do all this? Enter the Personal Electric Vehicle (PEV).

What Are PEVs?

PEVs are a nascent part of the transportation mix that fall under the wider umbrella of “micromobility,” including scooters, bikes, skateboards, and the like. The key differentiator here is that they are at least partially electrically-driven. [Gawthrop] walks us through several of the different types during his Supercon 2022 talk, but since they are all small, electric powered devices for transporting one or two people, they can trace their lineage back to the infamous Segway Human Transporter.

Using an electric motor or two connected to a controller and batteries, the overall system complexity for any of these devices is quite low and ripe for the hacking. Given the right tools and safety precautions, anyone should be able to crack a PEV open and repair or tinker with it. As with many things in life, the real story is more complicated.

As [Gawthrop] notes, many a hacker has said, “I wish I’d been able to be involved in X before…” where X equals some technology like home automation and it’s before it got creepy or dystopian in some manner. He exhorts us that the time to be in on the ground floor with PEVs is now. Continue reading “Supercon 2022: Bradley Gawthrop Wants You To Join The PEV Revolution”

One Wheel Is All We Need To Roll Into Better Multirotor Efficiency

Multirotor aircraft enjoy many intrinsic advantages, but as machines that fight gravity with brute force, energy efficiency is not considered among them. In the interest of stretching range, several air-ground hybrid designs have been explored. Flying cars, basically, to run on the ground when it isn’t strictly necessary to be airborne. But they all share the same challenge: components that make a car work well on the ground are range-sapping dead weight while in the air. [Youming Qin et al.] explored cutting that dead weight as much as possible and came up with Hybrid Aerial-Ground Locomotion with a Single Passive Wheel.

As the paper’s title made clear, they went full minimalist with this design. Gone are the driveshaft, brakes, steering, even other wheels. All that remained is a single unpowered wheel bolted to the bottom of their dual-rotor flying machine. Minimizing the impact on flight characteristics is great, but how would that work on the ground? As a tradeoff, these rotors have to keep spinning even while in “ground mode”. They are responsible for keeping the machine upright, and they also have to handle tasks like steering. These and other control algorithm problems had to be sorted out before evaluating whether such a compromised ground vehicle is worth the trouble.

Happily, the result is a resounding “yes”. Even though the rotors have to continue running to do different jobs while on the ground, that was still far less effort than hovering in the air. Power consumption measurements indicate savings of up to 77%, and there are a lot of potential venues for tuning still awaiting future exploration. Among them is to better understand interaction with ground effect, which is something we’ve seen enable novel designs. This isn’t exactly the flying car we were promised, but its development will still be interesting to watch among all the other neat ideas under development to keep multirotors in the air longer.

[IROS 2020 Presentation video (duration 10:49) requires no-cost registration, available until at least Nov. 25th 2020. Forty-two second summary embedded below]

Continue reading “One Wheel Is All We Need To Roll Into Better Multirotor Efficiency”

Homebuilt Onewheel Uses Hoverboard Parts

Since Back To The Future II first screened back in 1989, people have been waiting for hoverboards to become reality. Instead, we got a dangerous two-wheeled contraption going by the same name. Wanting something a little cooler, [Bartek Plonek] decided to convert his to a one-wheel design. (Video, embedded below.)

The hack starts by machining the hub motors of the hoverboard. They’re bolted together, and used as the hub of a single larger wheel. Care is necessary to avoid cracking the motor housing during this process, as [Bartek] found during his first attempt. The wheel is then fitted to the centre of a steel frame, upon which two halves of a skateboard are attached to act as a footplate. The original hoverboard controller is still used; we’d love to know if firmware modification was required to work with the new motor configuration.

It’s a classic garage hack that results in a viable personal electric vehicle. Plus, cornering is far easier, with the DIY onewheel capable of carving back and forth quite well. We’ve seen others aim to commute using similar builds.

Continue reading “Homebuilt Onewheel Uses Hoverboard Parts”

[Nick Thatcher]’s Plan-B Is A Commuter Electric Unicycle

[Nick Thatcher] is a serial builder of self-balancing rides. His various Segway clones and unicycles have until now suffered from one significant problem, that of portability when not being ridden. Taking one on a train was a significant undertaking, hardly convenient in a personal transport machine.

His latest design, the Plan-B, is an electric unicycle designed to address this problem to create a truly portable piece of commuter transport. It has been designed to be as compact as possible with the ability to fold to fit in a confined space, and the weight has been reduced to a minimum.

Power comes from a 24V 350W geared motor kept on a leash through a Dimension Engineering motor controller by an Arduino with a gyro to maintain the unit’s stability The battery is an ULTRAMAX LiFePO4 , and the single wheel is an inexpensive plastic wheelbarrow part with chain drive from the motor.

The result is both rideable and portable, though with a 10mph top speed not the fastest of personal transport. He’s posted a video which you can see below the break, showing him taking it on a train journey and traversing the British urban landscape.

Continue reading “[Nick Thatcher]’s Plan-B Is A Commuter Electric Unicycle”

Self-Balancing One-Wheel Motorcycle Tears Up The Beach

[XenonJohn] wrote in to let us know about updates and a recent test drive of an Electric Self-Balancing One-wheeled Motorcycle, fresh from the beach where he says it proved to be great fun to ride. The design and build have been updated since we last saw it as a semifinalist entry in the 2014 Hackaday Prize. The original, he says, “looked cool but was slow, cumbersome and really dangerous to ride.”

electric self-balancing unicycle - thumbnailSince then it has been completely redesigned and now has a super fat kite-surfer wheel, a front crash skid with damper, and a variable geometry which allows it to steer properly despite just having one wheel. It does this by allowing the rider to shift their position relative to the wheel, instead of the seat always being rigidly locked directly above the axle.

That steering is a pretty clever upgrade, but we do wonder if the new crash skid will have an atlatl effect and really launch the rider in a crash. Our gut feeling aside, it is designed not to plant itself in the pavement, but to slide along (without ejecting the rider) until the vehicle loses all momentum.

There is something about self-balancing unicycles that attracts experimenters, each of whom takes a different approach. We see everything from this device constructed mainly from a Razor Scooter to this more polished-looking unit based on an earlier Segway clone design. [XenonJohn] reminds us that “there is still much to learn in this area and you can genuinely innovate even as a hobbyist. Also, you can only do so much on a computer, you then have to actually build something and see how well it works. [This recent test] shows what you can do if you just keep on experimenting.” Video of the test drive is below.

Continue reading “Self-Balancing One-Wheel Motorcycle Tears Up The Beach”