[Lou’s] friends all said that it would be impossible to build a unicycle that had offset pedals. Moving the pedals to the front of the unicycle would throw off the balance and prevent the user from being able to ride it. [Lou] proved them wrong using mostly components from a single donor bicycle.
The donor bike gets chopped up into a much smaller version of itself. The pedals stay attached in the original location and end up being out in front of the rider. The seat is moved backwards, which is the key to this build. Having the rider’s legs out in front requires that there be a counter balance in back. Moving the seat backwards gets the job done with relative ease.
To prevent the hub from free wheeling, [Lou] lashes the sprocket directly to the wheel spokes using some baling wire. He also had to remove the derailer and shorted the chain. All of this gives the pedals a direct connection to the wheel, allowing for more control. The video does a great job explaining the build quickly and efficiently. It makes it look easy enough for anyone to try. Of course, actually riding the unicycle is a different matter. Continue reading “Offset Unicycle Built Mostly from a Single Bicycle”
Despite a seeming lack of transportation projects for The Hackaday Prize, there are a few that made it through the great culling and into the semifinalist round. [Nick], [XenonJohn], and [DaveW]’s project is the Medicycle. It’s a vehicle that will turn heads for sure, but the guys have better things in mind than looking cool on the road. He thinks this two-tire unicycle will be useful in dispatching EMTs and other first responders, weaving in and out of traffic to get where they’re needed quickly.
First things first. The one-wheeled motorcycle actually works. It’s basically the same as a self-balancing scooter; the rider leans forward to go forward, leans back to break, and the two tires help with steering. It’s all electronic, powered by a 450W motor. It can dash around alleys, parking lots, and even gravel roadways.
The medi~ part of this cycle comes from a mobile triage unit tucked under the nose of the bike. There are sensors for measuring blood pressure and oxygen, heart rate, and ECG. This data is sent to the Medicycle rider via a monocular display tucked into the helmet and relayed via a 3G module to a physician offsite.
Whether the Medicycle will be useful to medics remains to be seen, but the guys have created an interesting means of transportation that is at least as cool as a jet ski. That’s impressive, and the total build cost of this bike itself is pretty low.
Video of the Medicycle in action below.
The project featured in this post is a semifinalist in The Hackaday Prize.
Continue reading “THP Semifinalist: The Medicycle”
No one has time to hone their balancing skills these days, and if building your own Segway doesn’t generate enough head-turning for you, then the self-balancing unicycle from the guys at [Scitech] should. Their build is chain-driven, using easy-to-find salvaged Razor scooter parts. Throw in a motor controller, 5DOF IMU and some batteries and it’s almost ready to burn up the sidewalks in hipster-tech style.
Some of the previous unicycle builds we’ve seen are a little on the bulky side, but the [Scitech] cycle aims for simplicity with its square tube steel framing and footrests. As always, unicycle builds like these take some effort on behalf of the rider: shifting your weight controls steering and throttle. The [Scitech] gang also discovered that it’s usually best when you don’t accidentally wire the motors up to the controller backwards. We recommend that you find a helmet and watch the video after the break.
Too-cool-for-unicycle hackers can build a dangerously fast e-skateboard instead.
Continue reading “Yet Another Self-Balancing Unicycle”
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.
Continue reading “Self-balancing unicycle using Arduino and Sparkfun IMU”
[Glenn] had an old electric scooter/motorcycle in his garage that had long ago given up the ghost. Without a working battery and motor controller this scooter wasn’t beyond repair, but [Glenn] thought he could use it to build something much, much cooler. What he came up with is a self-balancing unicycle that borrows inspiration from a Segway and other self-balancing robots.
After cutting the drive chain off his scooter, [Glenn] began work on installing a new motor controller and battery. To make this unicycle balance itself, he would need a few gyroscopes and accelerometers provided via an Arduino and Sparkfun IMU shield.
After tuning his PID loop, [Glenn] hopped on his new ride and took it for a spin with the help of a pair of ski poles. It’s much easier to ride than a traditional unicycle and [Glenn] says he’s getting better at riding it.
This self balancing robot still uses just two wheels, but it’s balancing very differently than we’re used to seeing. Where most of the projects use a form factor that’s similar to a Segway, this works just like a bicycle. But it doesn’t need to keep the front and rear wheels spinning to stay upright. In fact, the video after the break shows it balancing perfectly while at a complete standstill. [Aoki2001’s] creation isn’t stuck in one place. He included distance sensors on the front and back which are used to move the bike as if by repulsion.
The large wheel where the rider would be is what makes sure the vehicle doesn’t topple over. It acts as an inverted pendulum, pushing against the large wheel’s inertia by rotating the motor to which it is attached. The same concept was seen back in march on a full-sized bike. But why use two wheels when you only need one? His unicycle version can also be seen embedded after the break.
It’s worth looking at [Aoki’s] other YouTube offerings too. He’s got a small robot which balances on top of a ball. It’s the desk-sized version of this hack.
Continue reading “Self balancer does it differently than we’re used to seeing”
The only problem with this self-balancing unicycle is it’s inability to balance itself. You see, it automatically balances along the axis that is parallel to the line of travel. But since there’s only one wheel the rider is responsible for balancing perpendicular to travel. This is really not too much different from a bicycle; balancing while in motion is pretty simple. Only when you slow down or stop are you in trouble.
[Stephen Boyer] built the vehicle and uses it for most of his travel around the MIT campus. It carries a pair of 12V batteries that pack enough punch to travel five miles between charges. A 5DOF board senses motion and orientation, with an ATmega328 microcontroller calculating the corrections necessary to keep the rider upright.
The demo video after the break never really gives you good look at the thing, but it’s enough to prove that it does indeed work very well. We’re also glad to see that [Stephen] is using a kill-switch while riding.
If you’re aching for more electric unicycle video check out this other project too. Continue reading “Self-balancing unicycle only for those with good balance”