Building an Electric Scooter That’s Street Legal, Even in Germany

Sometimes a successful project isn’t only about making sure all the electrons are in the right place at the right time, or building something that won’t collapse under its own weight. A lot of projects involve a fair amount of social engineering to be counted as a success, especially those that might result in arrest and incarceration if built as originally planned. Such projects are often referred to as “the fun ones.”

For the past few months, we’ve been following [Bitluni]’s DIY electric scooter build, which had been following the usual trajectory for these things – take a stock unpowered scooter, replace the rear wheel with a 250 W hub motor, add an ESC, battery, and throttle, and away you go. Things took a very interesting turn, however, when his street testing ran afoul of German law, which limits small electric vehicles to a yawn-inducing 6 kph. Unwilling to bore himself to death thus, [Bitluni] found a workaround: vehicles that are only assisted by an electric motor have a much more reasonable speed limit of 25 kph. So he added an Arduino with a gyro and accelerometer module and wrote a program to only power the wheel after the rider has kicked the scooter along a few times – no throttle needed. The motor stops after a bit, needing another push or two to kick it back on. A brake lever kills the motor, as does laying the scooter on its side. It’s quite a clever design, and while it might not keep the Polizei at bay, you can’t say he didn’t try.

[Bitluni] has quite a range of builds, from software-defined television to bad 3D-scanners to precision wine glass whacking. You should check out his stuff. Continue reading “Building an Electric Scooter That’s Street Legal, Even in Germany”

Need A Hand? How About Two?

A helping hand goes a long way to accomplishing a task. Sometimes that comes in the form of a friend, and sometimes it’s a pair of robotic hands attached to your arm.

Italian startup [Youbionic] have developed this pair of 3D printed hands which aim to extend the user’s multi-tasking capacity. Strapped to the forearm and extending past the user’s natural hand, they are individually operated by flexing either the index or ring fingers. This motion is picked up by a pair of flex sensor strips — a sharp movement will close the fist, while a slower shift will close it halfway.

At present, the hands are limited in their use — they are fixed to the mounting plate and so are restricted to gripping tasks, but with a bit of practice could end up being quite handy. Check out the video of them in action after the break!

Continue reading “Need A Hand? How About Two?”

The Hackaday Prize: An Open Electric Wheelchair

[Irene Sans] and [Alvaro Ferrán Cifuentes] feel that electric wheelchairs are still too expensive. On top of that, as each person’s needs are a little different, usually don’t exactly fit the problems a wheelchair user might face. To this end they’ve begun the process of creating an open wheelchair design which they’ve appropriately dubbed OpenChair.

As has been shown in the Hackaday Prize before, there’s a lot of things left to be desired in the assistive space. Things are generally expensive. This would be fine, but often insurance doesn’t cover it or it’s out of the range of those in developing nations.  As always, the best way to finish is to start, so that’s just what [Irene] and [Alvaro] has done.

They based their initial design on the folding wheel chair we all know. It’s robust enough for daily use and is fairly standard around the world. They designed a set of accessories to make the wheelchair more livable for daily use as well as incorporating the controls.

The next problem was locomotion. Finding an off-the-shelf motor that was powerful enough without breaking the budget was proving  difficult, but they had an epiphany. Why not use mass production toy crap to their advantage. The “hoverboards” that were all the rage this past commerical holiday season were able to roll a person around, so naturally a wheelchair would be within the power range.

They extracted the two 350 watt hub motors, batteries, and control boards. It took a bit of reverse engineering but they were able to get the hub drive motors of the hoverboard integrated with the controls on their wheelchair.

In the end they were able to cut the price of a regular electric wheelchair in half with their first iteration and set the foundation for future work on an open electric wheelchair system. Certainly more work could bring even better improvements.