John Dingley, the guy behind last year's electric luge, has been in the workshop again. This time he's been working on a new version of his self-balancing electric unicycle. Similar to the Ryno, but home built and using a brushless motor.
Dingley's original unicycle – called the Lunar Rover – was built using a brushed DC electric motor and chain drive. For his latest project, he's managed to go brushless and ditch the chain. The Mega Hub Motor Electric Unicycle is built around a 3,000 W brushless hub motor within a 17-inch wheel sourced from China, and features a Kelly motor controller designed for electric boats (used here to enable a reverse mode as Dingley found that most e-bike controllers were rigged to go forward only).
A cylindrical aluminum tube up top acts both as seating for the rider and home to the battery pack, which is made up of 20 LiFePO4 cells. The torpedo-like tube is ended with a jet intake from an old aircraft, while the unicycle's self-balancing electronics have been squeezed into a Ural motorcycle headlamp pod from the 1950s.
Instead of a mid-handlebar visual display, Dingley's unicycle was treated to audio alarms and status updates driven by Arduino brains and created using "Talkie" speech synthesis. And there's a small stabilizer wheel out front in case of nose dives.
"The steering system is similar to the one in my previous machine," revealed Dingley. "It looks as if you are shifting your weight left and right by turning the handlebars but actually this is not true. You are the heaviest part of the machine and so when you turn the handlebars, the wheel leans over onto one edge of the tire, because the hinge joint at the back between upper and lower parts of the frame is not vertical but angled, and you stay more or less where you were before. The tire contact patch is now curved and so will start you turning to one side."
There are detailed build videos available via the source link, and you can see Dingley zipping along the beach on his electric unicycle in the video below – as well as a demonstration of the old school braking system.
Source: John Dingley