Hoverboard Reborn For Electric Rollerblading

October 31, 2017 by Dan Maloney 8 Comments

Rollerblading is fun, but who needs all that pesky exercise? Wouldn’t strapping on the blades be so much more tempting if you had an electric pusher motor to propel you along your way?

We have to admit that we raised a wary eyebrow as we first watched [MakerMan]’s video below. We thought it was going to be just another hoverboard hack at first, but as we watched, there were some pretty impressive fabrication skills on display. Yes, the project does start with tearing into a defunct hoverboard for parts, primarily one wheel motor and the battery pack. But after that, [MakerMan] took off on a metalworking tear. Parts of the hoverboard chassis were attached to a frame built from solid bar stock — we’ll admit never having seen curves fabricated in quite that way before. The dead 18650 in the battery pack was identified and replaced, and a controller from an e-bike was wired up. Fitted with a thumb throttle and with a bit of padding on the crossbar, it’s almost a ride-upon but not quite. It seems to move along at quite a clip, even making allowances for the time-compression on the video.

We’ve seen lots of transportation hacks before, from collapsible longboards to steam-powered bicycles, but this one is pretty unique.

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Instrument Packed Pedal Keeps Track Of Cyclist’s Power

October 28, 2017 by Dan Maloney 13 Comments

Exactly how much work is required to pedal a bike? There are plenty of ways to measure the power generated by a cyclist, but a lot of them such as heavily instrumented bottom brackets and crank arms, can be far too expensive for casual use. But for $30 in parts you can build this power-measuring bike pedal. and find out just how hard you’re stoking.

Of course it’s not just the parts but knowing what to do with them, and [rabbitcreek] has put a lot of thought and engineering into this power pedal. The main business of measuring the force applied to the crank falls to a pair of micro load cells connected in parallel. A Wemos, an HX711 load-cell amp, a small LiPo pack and charging module, a Qi wireless charger, a Hall sensor, a ruggedized power switch, and some Neopixels round out the BOM. Everything is carefully stuffed into very little space in a modified mountain bike pedal and potted in epoxy for all-weather use. The Hall sensor keeps tracks of the RPMs while the strain gauges measure the force applied to the pedal, and the numbers from a ride can be downloaded later.

We recall a similar effort using a crank studded with strain gauges. But this one is impressive because everything fits in a tidy package. And the diamond plate is a nice touch.

Hackaday Prize Entry: Bellcycles Are Open-Source, Compact, And Unique

October 12, 2017 by Brian McEvoy 37 Comments

What do we want in a bicycle? It should be able to be constructed at home, even if your home is a New York apartment. It should be Open Source so our friends can make their own. It should be compact so it won’t clutter up our little apartments. It should be unique instead of another me-too. [Alex Bell], of Bellcycles, is showing off his bicycle on hackaday.io and it fills all the requirements.

The unusual shape drastically reduces the size, turning radius, and storage footprint from a traditional bicycle. It shares the large front wheel design of the penny farthing. Unlike the giant wheeled penny-farthing, the rider is much closer to the ground so it doesn’t require a special technique to get on. In fact, dismounting the cycle is as easy as standing up since there is nothing in front of the rider which is great news for urban commuting.

If practicality takes a back seat to peculiarity, check out this Strandbeest bicycle and if you’d just rather stay in your apartment, you can still take a worldwide cycling tour in VR.

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Trike With Water-Rocket Engine

September 27, 2017 by Brian McEvoy 32 Comments

Many of us made soda bottle rockets for science class. Some of us didn’t have that opportunity, and made them in the backyard because that’s what cool kids do. Water rockets work on the premise that if water is evacuated from one side of a container, the container will accelerate away from the evacuation point. Usually, this takes the form of a 2-liter bottle, a tire pump and some cardboard fins. [François Gissy] modified the design but not the principle for his water trike which reached 261 kph or 162mph.

Parts for the trike won’t be found in the average kitchen but many of them could be found in a motorcycle shop, except for the carbon fiber wrapped water tank. There wasn’t a throttle on this rocket, the clutch lever was modified to simply open the valve and let the rider hold on until the water ran out. The front brake seemed to be intact, thank goodness.

Powering vehicles in unconventional ways is always a treat to watch and [François Gissy]’s camera-studded trike is no exception. If you like your water rockets pointed skyward, check out this launch pad for STEM students and their water rockets. Of course, [Colin Furze] gets a shout-out for his jet-powered go-kart.

Thank you, [Itay], for the tip.

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Salvaging Your Way To A Working Tesla Model S For $6500

September 20, 2017 by Adil Malik 80 Comments

If you possess modest technical abilities and the patience of a few dozen monks, with some skillful haggling you can land yourself some terrific bargains by salvaging and repairing. This is already a well-known ideology when it comes to sourcing things like electronic test gear, where for example a non working unit might be purchased from eBay and fixed for the price of a few passive components.

[Rich] from Car Guru has taken this to a whole new level by successfully salvaging a roadworthy Tesla Model S for $6500!

Sourcing and rebuilding a car is always a daunting project, in this case made even more challenging because the vehicle in subject is fairly recent, state of the art electric vehicle. The journey began by purchasing a black Tesla Model S, that [Rich] affectionately refers to as Delorean. This car had severe water damage rendering most of its electronics and mechanical fasteners unreliable, so [Rich’s] plan was to strip this car of all such parts, and sell what he could to recover the cost of his initial purchase. After selling the working modules of the otherwise drenched battery, motor and a few other bells and whistles his initial monetary investment was reduced to the mere investment of time.

With an essentially free but empty Tesla shell in his possession, [Rich] turned his attention to finding a suitable replacement for the insides. [Rich] mentions that Tesla refused to sell spare parts for such a project, so his only option was to purchase a few more wrecked vehicles. The most prominent of these wrecks was nicknamed Slim Shady. This one

had an irreparable shell but with most electronics preserved, and would serve as the donation vehicle. After painstakingly transplanting all the required electronics and once again selling what he did not need, his net investment came to less than 10% of a new car!

Was all of the effort worth it? We certainly think it was! The car was deemed road worthy and even has functioning Super Charging capabilities which according to [Rich] are disabled by Tesla if such a Frankenstein build is detected.

At this point it would probably be instructive to ask [Rich] if he would do it again, but he is already at it, this time salvaging the faster self driving P86. We suggest you stay tuned.

[Thankyou to Enio Fernandes for sending in the tip]

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A Jet Engine On A Bike. What’s The Worst That Could Happen?

September 18, 2017 by James Hobson 76 Comments

On today’s edition of ‘don’t try this at home,’ we’re transported to Russia to see [Igor Negoda]’s working jet bicycle.

This standard mountain bike comes equipped with a jet engine capable of 18kg of thrust, fixed to the frame under the seat with an adjustable bracket to change it’s angle as needed. A cell phone is zip-tied to the frame and acts as a speedometer — if it works, it’s not stupid — and an engine controller displays thrust, rpm and temperature. A LiPo battery is the engine’s power source with a separate, smaller battery for the electronics. The bike is virtually overgrown with wires and tubes that feed the engine, including an auxiliary fuel tank where a water bottle normally resides. Where’s the main fuel tank? In [Negoda]’s backpack, of course.

It certainly kicks up a mean dust cloud and makes a heck of a racket but the real question is: how fast does it go? From the looks of the smartphone, 72 km/h, 45 mph, or 18 rods to the hogshead.

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Open Source High Power EV Motor Controller

September 11, 2017 by Anool Mahidharia 34 Comments

For anyone with interest in electric vehicles, especially drives and control systems for EV’s, the Endless-Sphere forum is the place to frequent. It’s full of some amazing projects covering electric skateboards to cars and everything in between. [Marcos Chaparro] recently posted details of his controller project — the VESC-controller, an open source controller capable of driving motors up to 200 hp.

[Marcos]’s controller is a fork of the VESC by [Benjamin Vedder] who has an almost cult following among the forum for “creating something that all DIY electric skateboard builders have been longing for, an open source, highly programmable, high voltage, reliable speed controller to use in DIY eboard projects”. We’ve covered several VESC projects here at Hackaday.

While [Vedder]’s controller is aimed at low power applications such as skate board motors, [Marcos]’s version amps it up several notches. It uses 600 V 600 A IGBT modules and 460 A current sensors capable of powering BLDC motors up to 150 kW. Since the control logic is seperated from the gate drivers and IGBT’s, it’s possible to adapt it for high power applications. All design files are available on the Github repository. The feature list of this amazing build is so long, it’s best to head over to the forum to check out the nitty-gritty details. And [Marcos] is already thinking about removing all the analog sensing in favour of using voltage and current sensors with digital outputs for the next revision. He reckons using a FPGA plus flash memory can replace a big chunk of the analog parts from the bill of materials. This would eliminate tolerance, drift and noise issues associated with the analog parts.

[Marcos] is also working on refining a reference design for a power interface board that includes gate drivers, power mosfets, DC link and differential voltage/current sensing. Design files for this interface board are available from his GitHub repo too. According to [Marcos], with better sensors and a beefier power stage, the same control board should work for motors in excess of 500 hp. Check out the video after the break showing the VESC-controller being put through its paces for an initial trial.

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