An ebike motor with the controller cover removed. A number of wires and connectors take up most of the space in the cavity.

Open Brain Surgery For EBikes And EScooters

November 6, 2023 by Navarre Bartz 7 Comments

Personal Electric Vehicles (PEVs) all contain the same basic set of parts: a motor, a battery, a motor controller, some sensors, and a display to parse the information. This simplicity allowed [casainho] to develop a custom controller setup for their own PEVs.

Built around the venerable VESC motor controller, [casainho]’s addition is the EBike/EScooter board that interfaces the existing motor of a device to the controller. Their ESP32-powered CircuitPython solution takes the sensor output of a given bike or scooter (throttle, cadence, or torque) and translates it into the inputs the controller uses to set the motor power.

They’ve also designed an ESP32-based display to interface the rest of the system to the user while riding. Since it also runs CircuitPython, it’s easy to reconfigure the functions of the three button device to display whatever you’d like as well as change various drive modes of your system. I know I’d love to see my own ebikes have a different mode for riding on road versus on shared paths since not getting run over by cars and not harassing pedestrians aren’t going to have the same power profile.

If you want to find more ways to join the PEV revolution, check out this wild omni-wheeled bike or this solar car built from two separate e-bikes. If that doesn’t suit your fancy, how about an off-label use for an e-bike battery to power your laptop off grid?

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

July 3, 2023 by Navarre Bartz 70 Comments

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” →

Electric Skateboard Becomes Mobile Skate Park

March 30, 2023 by Bryan Cockfield 4 Comments

While building a skate park might not appear to have much in common with software development, at they very least, they both suffer from a familiar problem: scalability. Bigger skate parks need more ramps and features, and there’s no real way to scale up a construction project like this efficiently like you could with certain kinds of software other than simply building more features. This was something [Kirk] noticed, but was able to scale up a skate park in a way we’ve never thought of before. He built a mobile skateboard ramp that can turn any place into a skate park.

The mobile and approximately sidewalk-width platform is able to move around thanks to an electric skateboard as its foundation. It adds a NVIDIA Jetson Nano for control with a PS4 controller for input, although steering a skateboard with an actuator took a few prototypes to figure out since skateboards are designed to be steered by shifting the rider’s weight. Since they are already designed to carry a human-amount of weight, though, it was at least able to tote the ramp around with relative ease. Another problem was lowering the ramp into position when it got to the desired area, but with an electrically-controlled jack and a few rounds of debugging was eventually able to do this without much issue.

With all of that project development behind him, [Kirk] can finally realize his dream of having ramps scattered all across his neighborhood like in the classic videogame Paperboy, without needing to build them all individually or ask for permission to place them around his neighbor’s homes. For any future iterations of this build, we might consider adding tank tracks to the electric skateboard for better off-road performance, like facilitating a jump across a patch of grass.

3-Wheeled Electric Skateboard Does Things Differently

February 9, 2022 by Lewin Day 6 Comments

Typically, electric skateboards drive one or more wheels with brushless motors, while keeping everything mounted on otherwise fairly-standard trucks to maintain maneuverability. However, [swedishFeetballs] decided to go a different route, building a 3-wheeled design using some interesting parts.

The build relies on a large combined hub motor and wheel, similar to those you would find on a hoverboard or some electric scooters; this one is a Xiaomi part sourced from eBay. It’s controlled via an off-the-shelf electric skateboard speed controller that comes complete with its own remote.

The hardware is all bolted up to a custom skateboard deck built from scratch to accept the large single rear wheel. Up front, a regular skateboard truck is used. Batteries are mounted under the deck. Reportedly, the board has a top speed of 15 mph, which unsurprisingly matches that of the Xiaomi M365 the hub motor is sourced from.

It’s a neat way to build an electric skateboard, and to be honest we couldn’t be more curious as to how it rides. Unfortunately, only a few seconds of footage is available, but we’ve embedded it below for your watching pleasure!

Meanwhile, you might also be curious as to the benefits of a half-track skateboard. Video after the break.

Continue reading “3-Wheeled Electric Skateboard Does Things Differently” →

Tank Track Skateboard

December 25, 2020 by Danie Conradie 8 Comments

As electric skateboards kits and components become more commonly available, you really need to do something different to make your custom board stand out. [Emiel] [The Practical Engineer] has managed to do this by building a half-track skateboard. (Video, embedded below.)

Except for the front trucks, fasteners and bearings, all the mechanical components on the board were custom-made. The sturdy rear chassis and the track sections were machined from aluminum plate, and the wheels and track linkages were machined from POM/Delrin. The large carbon fiber deck and the polyurethane pads on the tracks were custom molded, which [Emiel] covered in detail in separate videos, also below. Two beefy brushless motors drive the tracks and are powered by LiPos in enclosed in the sheet metal electronics box. The final product looks very well-built and refined, especially considering most of the work happened in a tiny 2 m x 3 m workshop.

It looks like the board handles gravel paths well, but we would really like to see how it performs on soft surfaces like sand, where even off-road skateboards can struggle. It struggled a bit with low RPM torque, so a slight gearing change is in this board’s future.

Everything is cooler with tank tracks. If you’re willing to live with plastic tracks, 3D printing is a viable option, as demonstrated by [rctestflight]’s tracked rover and [Ivan Miranda]’s tank skateboard. Continue reading “Tank Track Skateboard” →

Electric Skateboard With Tank Tracks, From A Big 3D Printer

July 31, 2020 by Danie Conradie 4 Comments

One of the basic truths of ground vehicles is that they are always cooler with tank tracks. Maybe not better, but definitely cooler. [Ivan Miranda] takes this to heart, and is arguably the king of 3D printed tank projects on YouTube. He has built a giant 3D printed electric skateboard with tank tracks with the latest version of his giant 3D printer. Videos after the break.

The skateboard consists of a large steel frame, with tracked bogies on either end. Most of the bogie components are 3D printed, including the wheels and tracks, and each bogie is driven by a brushless motor via a belt. Some bends were added to the steel frame with just 3D printed inserts for his bench vice. The bogies are mounted to the frame with a standard skateboard truck, which allows it to steer like a normal skateboard, by tilting the deck. It looks as though this works well on a smooth concrete floor, but we suspect that turning will be harder on rough surface where the tracks can’t slide. We’ll have to wait for the next video for a full field test.

The large components for this skateboard were printed on [Ivan]’s MK3 version of his giant 3D printer. Although it’s very similar to the previous version, improvements were made in key areas. The sliding bed frame’s weight was reduced by almost 50%, and the wheels were rotated, so they ride on top of the extrusion below it, instead of on it’s side, which helps the longevity of the wheels. This also allows bed levelling to be done by turning the eccentric spacers on each of the wheels. The rigidity of base frame and x-axis beam were increased by adding more aluminium extrusions. Although he doesn’t explicitly mention the print volume, it looks to be the same as the previous version, which was 800x500x500. For materials other than PLA, we suspect a heated build chamber will be required have any chance of making big prints without excessive warping.

[Ivan] really likes big prints, with a number of 3D printed tanks, a giant nerf gun, and a sand drawing bot. Continue reading “Electric Skateboard With Tank Tracks, From A Big 3D Printer” →

Pop A Wheelie With Your Electric Skateboard, The Hacker Way

March 20, 2020 by Danie Conradie 9 Comments

Using a bit of tech to make up for a lack of skill is a time-honoured tradition, otherwise known as cheating among those who acquired the skill the hard way. Learning to ~~wheelie~~ manual a skateboard is usually paid for in bruises, but [blezalex] got around that by letting his electric skateboard handle the balancing act.

At first glance the board looks and rides like an average DIY electric skateboard, with an off-the-shelf a dual hub motor truck, VESC speed controllers and a wireless throttle. The party trick appears when the front wheel is popped off the ground, which activates the secret self-balancing mode. At this point a STM32F401 dev board and MPU-6050 IMU take over control of the motors, which is in turn controlled by leaning forward or backwards, like a hoverboard. The remote throttle turns into a dead man switch, which cuts power to the motors when released.

[blezalex] says he has had less that an hour of skateboard time in his life before getting on this one, which is a good testament of just how well it works. The biggest challenge was in getting the board to turn while on two wheels, which was solved by sensing side-to-side tilt of the board with the IMU and applying proportional differential torque to the wheels. With a bit of practice it’s also possible to smoothly shift between riding modes while moving.

We think this is a really elegant cheat, now we need to build one of our own. Fortunately the STM32 firmware and instructions are all up on GitHub. Building your own electric skateboard has become really simple with the availability of off-the-shelf components. We’ve also seen a bicycle with a wheelie cheat device to prevent you falling on your back