3D printed bike shifter

Shifter

[Rich] is embarking on a fairly long bike trip in a few weeks – Seattle to Portland – and thought including some 3D printed gear on his ride would be a fun endeavor. His first idea was a printed belt drive, but the more he looked at that idea the less realistic it seemed. He finally hit upon the idea of creating a 3D printed bike shifter, and after an afternoon of engineering and printing, the shifter ended up working very well.

[Rich]‘s shifter is actually a friction shifter. Instead of ‘clicking’ into position, this type moves the derailleur gradually. It’s much more tolerant of slight misalignment, and most touring bikes – the type that would embark on long journeys along the coast of the Pacific northwest – have these types of shifters.

Total printing time was about one and a half hours, and was attached to [Rich]‘s bike with off-the-shelf hardware. He’s already put about 150 miles on his custom designed shifter with no signs of failure.

A black box for a motorcycle

ecu

[Lukusz] has a new motorcycle – a Yamaha XJ6SA – and since it hasn’t been in an accident yet, he thought building a black box to record telemetry from the last 30 minutes of riding would be a good idea. While the project isn’t complete yet, he’s already reading data coming straight from the engine control unit.

After figuring out most of the pinout for his bike’s ECU connector, [Lukasz] found one wire that didn’t actually do anything. This was his ECU’s K line, a serial output that is able to relay the state of the gauges to external devices. The electronic spec of the K line is a bit weird, though, but luckily after finding a chip to convert the signal into something a logic analyzer can understand.

With a logic analyzer connected to the K line – and setting it to receive on at 16064 baud – [Lukasz] was able to get a whole lot of data directly from his bike. In the future he plans to pass data such as speed, indicator lights, RPMs, and the current gear to a Raspberry Pi for logging.

Dynamic bicycle headlight uses the open road as a display

dynamic-bike-headlight

This thing is so cool it almost looks fake. But [Matt Richardson] isn’t a hoaxster. He actually built what might be called a heads-down display for your bicycle. He refers to it as a headlight because it borrows a similar function. It mounts on the handlebars and shoots light off the front of the bike. But it’s more than just a battery and a bulb, this uses a pico-projector to give that light some meaning. In the video after the break he shows it off on the streets of NYC.

So far he’s only displaying information that has to do with the speed of travel, but the proof is there just waiting for a brilliant new use. Feeding the projector is a Raspberry Pi board. For this prototype [Matt] mounted it, along with the portable cellphone charger which plays the role of the power source, on a hunk of hardboard strapped inside the bike frame.

If you’re thinking of doing this one yourself beware of the BOM price tag. That projector he’s using runs upwards of $400. We wonder if you could hack together a rudimentary replacement with an old cellphone screen and this diy film projector?

[Read more...]

Brake Light Backpack overpowered with LED pixels

led-motorcycle-backpack

Here’s another Flora Arduino based project from [Becky Stern]. It’s a backpack with brake lights and turn signals for use when motorcycling, but it should work just as well for bicyclists. From this view the project looks pretty normal, but things get downright crazy when she decided to use the WS2801 pixels for the LEDs. Sure they take all the work out of driving an array of LEDs, and they offer full color and dimming levels. But when you see the bulk of cabling and PCBs this adds to the project (shown in the video after the break) we think you’ll agree that this was an interesting choice.

That issue aside the project is a lot of fun. The system doesn’t patch into the motorcycle’s electronics. Instead, it uses an accelerometer to detect when the brakes are applied and light the LEDs according. The turn signals are switched with an RF remote control that can be mounted on the handlebars.

Anyone looking to hack outerwear with electronics can learn form the fabrication techniques used here. [Becky] details how to make holes in the bag and sew parts to them, as well as using Sugru to waterproof vulnerable components.

[Read more...]

Brilliant auto-off feature for a bike light

auto-off-bike-light-switch

If you’re going to use your bicycle as transportation at night you really must have a head and tail light in hopes that the crazy drivers don’t hit you. For good reason, these lights don’t turn themselves off. But [Miceuz] kept forgetting to shut it down upon arrival and always ended up with dead batteries. His quest for an auto-off feature that actually worked ended in a brilliant and simple add-on circuit.

He first thought about using an accelerometer, but couldn’t find one that fit the bill without also adding a microcontroller. He came up with an even simpler circuit, which can be seen at the base of the black plastic housing. It’s a bit of copper clad board with a small spring attached. The spring completes an RC timer circuit which drives a MOSFET. When that circuit is charged, the MOSFET connects power to the bike light. When the cap runs out the MOSFET threshold cuts power and everything turns off. Since the spring jiggles while he rides it provides the momentary connection necessary to charge the capacitor. Stay stationary for about 30 seconds and the auto-off kicks in.

Robot performing a tightrope act

This robot is able walk the tightrope (translated). Well, it’s more of a shuffle than a walk, but still a lot better than we could do.

In the video after the break you can see the bot starting on the platform to the right. As it steps out onto the wire (which rides in a groove on the bottom of its foot) the robot spreads its arms to help maintain balance. When the other foot leaves the platform that is the last stride we will see until it reaches the other side. The rest of the act consists of sliding the feet a little bit at a time until it gets all the way across.

[Dr. Guero] has been working on at least one other balancer as well. Also embedded after the break is a robot riding a bicycle. It actually puts a foot down when stopped, and gives a stuttering push-off to get going again. This guy would be right at home riding past you in the hallways of the Death Star.

[Read more...]

Turn signals on your head

Several weeks ago, I was in Culver City L.A., and happened to find a hackerspace nearby. It was a pleasant coincidence that the night I chose to randomly show up, was their public meeting which focused more on projects people were doing. The place was packed, I was barely able to squeeze in the door and actually stood outside for part of the meeting, just listening to people talk about what they’re making.

One of the projects I did get to see was this bike helmet built by [Naim]. At first I was amused at the idea, but the idea of putting lights and an accelerometer on a helmet wasn’t that groundbreaking. But as [Naim] kept talking, he caught my attention. For one thing, the one he was showing at the hackerspace seemed to have some built in correction for natural head movement. In this video he does look around a bit without false positives. At the hackerspace he explained the way he monitors the motion to avoid natural movements causing the lights to initialize.

The part I was really interested in was his power. He spent tons of time reducing the power consumption on the base arduino. I believe the number he used was 10 years of standby without causing the battery to vent or die. If you pick up the helmet at any point during that time period, it automatically turns itself on based on the accelerometer’s motion. While the bike helmet itself was a fairly cute idea, I was really trying to get him to send me the information on how he’s saving power. I believe he had to cut the traces to the arduino’s native power management. Hopefully we’ll still hear from him on the details.

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