Revamping The Camping Trailer With More Power

Pulling a trailer behind your bike has an aspect of freedom and exploration to it. However, the reality is that pulling a large, heavy box behind your bike is incredibly draining physically. So [Drew] returned to the drawing board for his bike camper and added a motor, making some tweaks along the way.

We covered his first attempt at a bike trailer; this update encompasses everything he mentioned as future improvements. First, he strengthened the axle, and the trailer mount bolted straight into the chainstay arm for added strength. Then he built a custom battery pack out of 18650 cells clocked in at just under 3kw. Next, he installed a hub motor kit into the bike’s back wheel. Finally, a flexible 100W PV solar panel was added to the roof and routed to a small battery bank inside that provides USB and a few AC outlets for laptops and phones while camping. [Drew] does note that he could charge the big e-bike battery with the smaller bank, but since the e-bike battery is much larger than the small one, it would take a few cycles.

[Drew] takes a journey to a music festival and is happy to report better stability and the battery having fantastic range even without him pedaling. We love seeing a good project revisited, and we hope [Drew] gets some good use out of his camper. Video after the break.

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Mahmut's kid in a helmet, riding the go-kart outside on pavement

Hoverboard Go-Kart Build Is A Delight To Watch

Hoverboards have been an indispensable material for hackers building their own vehicles in the last few years. [Mahmut Demir] shows how he’s built a hoverboard-powered go-kart for his son. Unable to hack the board’s firmware, he instead set out to reuse the hoverboard without any disassembly, integrating it into the go-kart’s frame as-is. This build is completely mechanical, distinguished in its simplicity – and the accompanying six minute video shows it all.

This go-kart’s frame is wood and quite well-built, with the kind of personal touch that one would expect from a father-son gift. Building the vehicle’s nose out of a trashcan gave us a chuckle and earned bonus points for frugality, and the smiley face-shaped wheel is a lovely detail. As for the ‘hoverboard reuse’ part, the board is pivoted backward and forward, just as it normally would be. Rather than feet, the kart uses a lever that’s driven with two pedals through a pulley-string arrangement, giving granular speed control and the ability to reverse. It’s a clever system, in fact we don’t know if we could’ve done it better. You can see [Mahmut]’s son wandering in the background as [Mahmut] goes through the assembly steps — no doubt, having fun doing his own part in the build process.

[Mahmut] tells us he’s also added a remote off switch as a safety feature, and we appreciate that. We’ve seen hoverboards in go-kart builds before, as well as rovers, e-bikes, robot vehicles, and even mobility platforms. Truly, the hoverboard is a unicorn of hacker transportation helpers.
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Young Inventor Builds Motor Without Rare Earths

[Robert Sansone] is a 17-year-old from Florida and, like most of us, he likes to tinker. He’s apparently got the time for it because he’s completed at least 60 projects ranging from animatronic hands to a high-speed go-kart. However, his interest in electric vehicles coupled with his understanding of the issues around them led him to investigate synchronous reluctance motors — motors that don’t depend on expensive rare earth magnets. His experiments have led to a novel form of motor that has greater torque than existing designs.

Rare earths are powerful but expensive, costing much more than common metals like copper or steel. Traditionally, synchronous reluctance motors use steel rotors and air gaps and exploit the difference in reluctance — a term for magnetic resistance– to generate rotation. [Robert’s] idea was to replace the air gap with a different material to increase the ratio of reluctance between the rotor and the gap. Reconfiguring the motor to a more traditional configuration shows startling results: the new design generated almost 40% more torque and did so more efficiently, as well.

His work has earned him first prize, and $75,000, in this year’s Regeneron International Science and Engineering Fair. It took 15 tries to get the motor to its current state, something made easier with 3D printing. There are plans for a 16th version that [Robert] hopes will perform even better. We can’t wait to see what he’ll do next.

Electric vehicles have made people look into many motor design topologies. The reluctance motor has been around for a long time, but controlling them has become significantly easier. That’s true of many kinds of motors.

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Hoverboard Powered Sofa Is Fun And A Bit Dangerous

Discarded hoverboards are a great source of free high torque motors for hacking. This can include crazy but fun projects like this hoverboard-driven IKEA sofa, as demonstrated by [Bitluni] and his friends at xHain Hackerspace in Berlin.

With a couple of dead hoverboards in various conditions and a working e-bike battery, the group started exploring different options to put together a usable drivetrain. The first attempt involved commanding the motor drivers directly by intercepting communication from the gyro-based controller. The 9-bit communication protocol was a tough nut to crack, so they tried (and failed) to use the gyro-boards directly as the controllers. In the process of researching they discovered someone had created alternative firmware for the hoverboard controllers to allow control with a Wii Nunchuck. There is even a web-based config tool for compiling the firmware.

With some wood spacers screwed to the bottom of the sofa, the hoverboard motors could be attached by simply screwing their enclosure to the bottom of the couch and adding a section of PVC pipe between the halves for wiring. Caster wheels were added to the rear corners of the sofa to complete the chassis. The motors were very sensitive to control inputs on the Nunchuck, so riding the couch tended to rapidly turn into a rodeo event. The couch also wasn’t made to carry its load on the outer corners, so it had to be reinforced with plywood after it started cracking.

We’ve seen plenty of hacks that involve hoverboard motors, including an electric skateboard with mecanum wheels and a surprisingly practical e-bike conversion.

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Simple Propulsion For The Lazy Paddle Boarder

One of the downsides to healthy outdoor activities is all the exercise. Who would want to do that if you can build something to do the hard work for you? That seems to be the theme of [Bitluni]’s latest build, a simple (and hacky) propulsion system for a stand-up paddleboard.

After acquiring an inflatable stand-up paddleboard and trying it out a few times, [Bitluni] decided to skip the “stand up” and “paddle” parts. He designed and printed a very simple propeller, which he intended to power with a brushless motor and speed controller. In the process of drilling out the prop to fit the shaft, he realized he was overcomplicating things. So he decided to just use his battery-powered drill instead. For the shaft tube, he modified an old crutch by drilling a hole in the handle for the shaft and adding a duct with a bearing on the other end. He also attached a carabiner to the handle to fix it to the paddleboard.

A test at a lake showed that the propulsion system performed relatively well for a proof of concept but had some flaws. To submerge it properly, [Bitluni] had to sit on the rear of the paddleboard facing backward. If it was too close to the surface, it would suck air and lose thrust, or spray him and his drill with water. Of course, there is also the real risk of drowning his drill in the process.

Projects don’t need to be complex to be enjoyable, and you can often learn more by quickly creating a proof of concept instead of taking forever to come up with the “perfect” design.

If you want to see some more advanced water-borne projects, check out the waterjet-powered electric surfboards built by [RCLifeOn] and [Andrew W].

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Trippy Bicycle Uses Multiple Partial Wheels

Bicycles need at least two wheels to be rideable, but [The Q] realized you don’t necessarily need the wheels to be in one piece. As long as you have at least two points of rolling contact with the ground, you can spread the load across multiple partial wheels. He demonstrated this by splitting the rear wheel of his bike first in half and then thirds to create an absolute head turner.

Since a conventional bicycle wheel with tensioned spokes would collapse if cut apart, [The Q] used single-piece aluminum wheels instead. The tires were cut into pieces, and the inner tubes were replaced with sections of thick-walled HDPE pipe that won’t collapse under the weight of a human. The tires and the HDPE “inner tubes” were riveted to the wheels.

To mount the additional wheels on the frame, [The Q] welded a set of extensions to the back with mounting points for the partial wheels. To keep them synced, timing is done with chains running on sprockets welded to the disc brakes. In the second video, he tries to also split the front wheels, but found the front forks can’t handle the torque and would flex dangerously when the contact point is too far forward. Instead, he settled for three wheels on the back.

Much like his hubless bicycle, it’s not designed to be better than a standard bicycle, but is excellent for attracting attention. Though at least in some situations, the all-wheel drive bike he built last year might come in handy.

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Probing CAN Bus For EV Battery Info

The widespread adoption of the CAN bus (and OBD-II) in automobiles was largely a way of standardizing the maintenance of increasingly complicated engines and their needs to meet modern emissions standards. While that might sound a little dry on the surface, the existence and standardization of this communications bus in essentially all passenger vehicles for three decades has led to some interesting side effects, like it’s usage in this project to display some extra information about an electric car’s battery.

There’s not a ton of information about it, but it’s a great proof-of-concept of some of the things CAN opens up in vehicles. The build is based on a Citroën C-Zero (which is essentially just a re-badged Mitsubishi i-MiEV) and uses the information on the CAN bus to display specific information about the state of charge of the battery that isn’t otherwise shown on the car’s displays. It also includes a build of a new secondary display specifically for this purpose, and the build is sleek enough that it looks like a standard part of the car.

While there are certainly other (perhaps simpler) ways of interfacing with a CAN bus, this one uses off-the-shelf electronics like Arduino-compatible microcontrollers, is permanently installed, and has a custom case that we really like. If you’re just starting to sniff around your own vehicle’s CAN bus, there are some excellent tools available to check out.

Thanks to [James] for the tip!

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