DIY electric personal vehicles are a field where even hobbyists can meaningfully innovate, and that’s demonstrated by the Mega-Wheelie, a self-balancing one-wheeled skateboard constructed as an experiment in traversing off-road conditions.

[John Dingley] and [Nick Thatcher] have been building and testing self-balancing electric vehicles since 2008, with a beach being a common testing ground. They suspected that a larger wheel was the key to working better on rough ground and dry sand and tested this idea by creating a skateboard with a single wheel. A very big, very wide wheel, in fact.

The Mega-Wheelie houses a 24V LiFePO4 battery pack, 450 W gearmotor with chain and sprocket drive, SyRen motor controller from Dimension Engineering, Arduino microcontroller, and an inertial measurement unit to enable the self-balancing function. Steering is done by leaning, and the handheld controller is just a dead man’s switch that disables the vehicle if the person piloting it lets go.

Design-wise, a device like this has a few challenging constraints. A big wheel is essential for performance but takes up space that could otherwise be used for things like batteries. Also, the platform upon which the pilot stands needs to be as low to the ground as possible for maximum stability. Otherwise, it’s too easy to fall sideways. On the other hand, one must balance this against the need for sufficient ground clearance.

In the end, how well did it work? Well enough to warrant a future version, says [John]. We can’t wait to see what that looks like, considering their past 3000 W unicycle’s only limitation was “personal courage” and featured a slick mechanism that shifted the pilot’s weight subtly to aid steering. A video of the Mega-Wheelie (and a more recent unicycle design) is embedded just below the page break.

And just for reference, here is some of [John]’s previous work on a self-balancing unicycle design.

Some people drive their car to work. Some walk. Others ride their bike. Well, in Nick Thatcher’s case, he prefers to hop on his own electric unicycle. The serial creator of self-balancing vehicles has just completed his latest project, dubbed  “Plan-B.”

Unlike his other builds, this time Thatcher set out to make Plan-B a true “commuter” unicycle with the utmost portability–boasting a foldable design, a handle on its rear for easy carrying, and a LiFePo4 battery to keep it lightweight.

His newly-constructed personal transport is equipped with a 24V 350W geared motor and a SyRen 50A motor controller, along with an Arduino Uno and an IMU to help maintain the cycle’s stability. Beyond that, Plan-B uses a wheelbarrow wheel with a chain drive from the motor.

Watch Thatcher commute in style below!

On the whim of a coin flip, Nick Thatcher once decided between building a homemade Segway, or a self balancing unicycle. Even though the powers of fate chose the former, Thatcher's thirst to build wasn't quenched -- he built the one-wheeled scooter anyway. The Raptor looks a lot like a Ryno unicycle built from spare parts -- a chain driven wheelbarrow wheel powered by a 350w geared motor, a pair of batteries wired in series, some PVC and polycarbonate, an IMU gyro and an Arduino UNO -- all hobbled together to form a one-wheeled electric mount. Thatcher says the scooter can push 10mph safely, but faster speeds tend to outpace the gyro's corrective efforts. Still, the bike promises between 90-120 minutes of face-plant free fun, provided the rider is at least a little balanced. The motorized unicycle isn't for sale, but peek on over to Thatch Industries for a parts list, or scoot on past the break to see the bike in action.

Filed under: Misc

Comments

Via: Hackaday

Source: Thatch Industries

Here’s proof that you can build cool stuff with simple tools. This self-balancing unicycle uses an Arduino and a five degree of freedom IMU from Sparkfun to keep the rider upright. Well, it’ll keep you upright as long as you have good side-to-side balance. But that’s true of any unicycle, right?

The Raptor was built by [Nick Thatcker] who is no stranger to self-balancing transportation. A few years back he built a Segway clone and the same type of geared motor used in that project also went into this one. I connects to the wheel with a chain, allowing him to keep the motor hidden in the saddle. He gets between 90 and 120 minutes of used on one charge with a top speed of 10 MPH. The motor could move you along faster but he has limited this in firmware to ensure it has enough power to ‘catch up’ if you lean too far forward.

Don’t miss the demo after the break. If you like this unicycle there are several others worth looking at.