Electric Bubblegum Board

The Mini Maker Faire in Atlanta was packed with exciting builds and devices, but [Andrew’s] Electric Bubblegum Boards stood out from the rest, winning the Editor’s Choice Award. His boards first emerged on Endless Sphere earlier this summer, with the goal of hitting all the usual e-skateboard offerings of speed, range, and weight while dramatically cutting the cost of materials.

At just over 12 pounds, the boards are lightweight and fairly compact, but have enough LiFePO4’s fitted to the bottom to carry a rider 10 miles on a single charge. A Wii Nunchuck controls throttle, cruise control, and a “boost” setting for bursts of speed. The best feature of this e-skateboard, however, is the use of 3D-printed parts. The ABS components not only help facilitate the prototyping process, but also permit a range of customization options. Riders can reprint parts as necessary, or if they want to just change things up.

[Andrew’s] board is nearing the 11th hour over at his Kickstarter page, so swing by to see a production video made for potential backers, or stick around after the break for some quick progress and demo videos.

Continue reading “Electric Bubblegum Board”

Replacing the Lead in a Motorcycle Battery with Supercaps

[Raphael] has a motorcycle he’s constantly working on, and for him that means replacing the battery occasionally. Tired of the lead-acid batteries that have been used for 100 years now, he took a look at some of the alternatives, namely lithium and the much cooler supercapacitor option. A trip to the local electronics distributor, and [Raphael] had a new supercapacitor battery for his bike, and hopefully he’ll never need to buy another chunk of lead again.

The battery pack is built from six 2.7V, 350F caps, a few connectors, and a handful of diodes. These are lashed together with rubber bands to form a 16V, 58F capacitor that makes for a great stand-in for a chunk of lead or a potentially puffy lithium battery.

[Raphael] put up a walkthrough video of his battery pack where he shows off the enclosure – an old, empty lead acid cell. He also goes through the back current protection and his method of balancing the supercaps with a few diodes.

The DIY Open Crank Engine Moped

Anyone can strap a two-stroke engine on a bicycle to create a moped. But [robinhooodvsyou] has created something infinitely more awesome. He’s built an inverted open crank engine on a 10 speed bicycle. (YouTube link)  As the name implies, the engine has no crankcase. The crankshaft, camshaft, and just about everything not in the combustion chamber hangs out in the open where it can be seen and appreciated.

[robinhooodvsyou] started with an air-cooled Volkswagen cylinder. He filled the jug with a piston from a diesel car. Camshaft, flywheel, valves, and magneto are courtesy of an old Briggs and Stratton engine. The cylinder head, crankshaft, pushrods, and the engine frame itself are all homemade.

Being an open crank engine, lubrication is an issue. The crankshaft’s ball bearing is lubricated by some thick oil in a gravity fed cup. Even though the engine is a four-stroke,[robinhooodvsyou] adds some oil to the gas to keep the rings happy. The camshaft and connecting rod use Babbit bearings. While they don’t have an automatic oiling system, they do look pretty well lubricated in the video.

Starting the engine is a breeze. [robinhooodvsyou] created a lever which holds the exhaust valve open. This acts as a compression release. He also has a lever which lifts the entire engine and friction drive off the rear wheel. All one has to do is pedal up to cruising speed, engage the friction drive, then disengage the compression release.

We seriously love this hack. Sure, it’s not a practical vehicle, but it works – and from the looks of the video, it works rather well. The unmuffled pops of that low 4:1 compression engine reminds us of old stationary engines. The only thing we can think to add to [robinhooodvsyou’s] creation is a good set of brakes!

Continue reading “The DIY Open Crank Engine Moped”

Auto Bike Light: On When Moving Off When Not

If you’re plagued by perpetually dead bike light batteries you’ll like this one. It’ll also fix the problem of remembering to turn the lights on in the first place. This hack uses an accelerometer to switch the light when the bike is in motion.

In this case the bike light was chosen for its ability to fit the control board inside the case. But with this proof-of-concept you can easily spin a tiny board with uC and accelerometer to replicate the functionality (the Bluetooth module shown above is going unused in this application). Many accelerometer chips have low-power mode that can be used to was a uC so we could easily see this having very little impact on the normally battery life of your light. The one caveat being the need to regulate the voltage as many of these lights take a 12V cell.

The other alternative is to make sure your battery is always charging during the day. This solar setup is one way, but then you won’t want to leave the thing unattended.

 

Even More Power Wheels Racers

With the Power Wheels Racing series wrapping up for the year, the teams are winding down and writing up their build and rebuild logs for their cars. In previous years, the kids from MIT, a.k.a. MITERS, have brought small electric cars to the races, but nothing like this. It’s a true Power Wheels, or at least the plastic shell, an alternator, a huge battery pack, and a completely custom drivetrain.

[Dane], [Ben], [Rob], [Mike], and [Ciaran] started their build with an alternator that was salvaged from [Charles]’ Chibi-Mikuvan, added a motor from a CDROM drive for a sensor, and basked in the glory of what this cart would become. The frame was crafted from 1″ square tube, a custom disc brake machined, and a 10S2P battery pack built.

The alternator the team used for a motor had a rather small shaft, and there were no readily available gearboxes. The team opted to build their own with helical gears milled on the MITERS Bridgeport mill. That in itself is worth of a Hackaday post. Just check out this video.

With the build held together with duct tape a baling wire, the team headed out to the races in Detroit. Testing the racer before getting to Detroit would have been a good idea. During the endurance race, a set of 10″ rear tires were torn apart in just four laps, impressively bad, until you realize the smaller pink tires that were also from Harbor Freight fared even worse.

After a few races, the MITERS team figured out the weaknesses of their car and managed to get everything working perfectly for the race at Maker Faire NY.

Continue reading “Even More Power Wheels Racers”

The Chibi-Mikuvan, or a Power Wheels with a Ford Fusion Battery

At all the big Maker Faires, the Power Racing Series makes an appearance, turning old Power Wheels into race cars that whip around the track at dozens of miles an hour. [Charles] is somewhat famous in the scene – there’s even a clause in the official rules named after him – so of course anything he brings to race day will be amazing. It was. It used a battery pack from a Ford Fusion plugin hybrid, a custom body, and a water cooling unit from a dead Mac G5.

A few months ago, we saw [Charles] tear into the battery pack he picked up for $300. This is the kind of equipment that will kill you before you know you’ve made a mistake, but [Charles] was able to take the pack apart and make a few battery packs – 28.8v and 16Ah – enough to get him around the track a few times.

The chassis for the Chibi-Mikuvan was built from steel, and the bodywork was built from machined pink foam, fiberglassed, and finished using a few tips [Charles] gleaned from [Burt Rutan]’s book, Moldless Composite Sandwich Aircraft Construction. The motor? That’s an enormous brushless motor meant for a 1/5th scale RC boat. The transmission is from an angle grinder, and the electronics are a work of art.

The result? A nearly perfect Power Wheels racer that has a curb weight of 110 pounds and tops out at 25 mph. It handles well, too: in the videos below, it overtakes the entire field of hacky racers in the Power Wheels Racing competition at Maker Faire NYC, and afterwards still had enough juice to tear around the faire.

Continue reading “The Chibi-Mikuvan, or a Power Wheels with a Ford Fusion Battery”

DIY Bike Brake Light And Turn Signals

If you ever take your bike out and share the road with large automobiles, you know that sometimes it can get a little hairy. As a biker, you will stand no chance in a collision with a vehicle. Communicating your intentions, i.e. turning and braking, can certainly reduce your risk of getting in an accident. [Mike] didn’t like the traditional idea of taking a hand off the handlebars in order to signal to traffic so he did something about it, he built turn signals and a brake light for his bike.

The business end of this project is the rear-facing light bar mounted under the rider’s seat. It is made from Radio Shack project boxes and mounted to an off-the-shelf L bracket. A bunch of LEDs were installed in the project boxes, the yellow turn signal LEDs are arranged in the shape of arrows and the red brake light LEDs are in an oval. Inside the project boxes you will find the 9v battery that powers the circuit and also a breadboard that is home to the circuits responsible for blinking the turn signals.

DIY Bike Turn Signals

Check out the switch assembly that is mounted to the handle bars. It was built using an old reflector bracket which was already the correct size to mount to handle bars. As you would expect, there is a toggle switch for turning the turn signals on and off. A little bit more interesting is the brake switch. It is a hinge-lever style limit switch and positioned in a manner such that it is activated when the brake lever is pulled. There is no additional thought or effort required on the cyclist’s part!

Something that is certainly not expected on the switch assembly is the headphone jack. [Mike] likes to listen to music while he rides and a cord dangling around from a backpack or bike bag gets in the way. On the rear light bar, there is a headphone jack that allows an MP3 player to be plugged into. The audio signals travel up the same CAT5 cord used for the turn and brake signals. This allows only a short run of headphone cable from the handlebars to [Mike’s] ears.