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.

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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.

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Electric Go-Cart Has Arduino Brains

arduino powered go cart

Oh how times have changed. Back in the 30’s the VW Beetle was designed to be cheap, simple and easy for the typical owner to maintain themselves. Nowadays, every aspect of modern cars are controlled by some sort of computer. At least our go-carts are spared from this non-tinkerable electronic nightmare…. well, that’s not completely true anymore. History is repeating itself as [InverseCube] has built an electronic go-cart fully controlled by an Arduino. Did I forget to mention that [InverseCube] is only 15 years old?

The project starts of with an old gas-powered go-cart frame. Once the gas engine was removed and the frame cleaned up and painted, a Hobbywing Xerun 150A brushless electronic speed controller (ESC) and a Savox BSM5065 450Kv motor were mounted in the frame which are responsible for moving the ‘cart down the road. A quantity of three 5-cell lithium polymer batteries wired in parallel provide about 20 volts to the motor which results in a top speed around 30mph. Zipping around at a moderate 15mph will yield about 30 minutes of driving before needing to be recharged. There is a potentiometer mounted to the steering wheel for controlling the go-cart’s speed. The value of the potentiometer is read by an Arduino which in turn sends the appropriate PWM signal to the ESC.

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Electric “Microkart” Has Tons Of Kick

Go Kart with Independent Suspension

When you’re building an electric go kart, you really have two options. Convert a normal gasoline powered one by swapping out the power plant… Or build it from scratch! [Ganharr] opted for the for the latter to save some money, and to design it just the way he wanted.

Now you may have noticed it looks a bit small — because it is. It’s really more of a Micro-Kart, but that’s okay because [Ganharr] is winning a father-of-the-year award for building it for his kid!

It features two 2kW (~3HP) brushless electric motors, which independently drive the rear wheels. These are powered by two 48V 50A continuous (100A peak) speed controllers.[Ganharr] also spared no expense on the batteries, opting for a 48V lithium-ion pack composed of Headway cells (3.2V 15aH capacity each, 40152 type).  Continue reading “Electric “Microkart” Has Tons Of Kick”

Introducing The Flux Buggy — A Serious Electric Dune Buggy Conversion

Believe it or not, the writers here at Hack a Day do their own projects too, we don’t just write about yours! I’ve just started a new project, and I want your advice! A few friends and I are converting a custom-made dune buggy — to electric.

The project will be chronicled over on Hackaday.io, with (hopefully) weekly updates on our progress. If you’ve been perusing Projects, you may have noticed my Electric Car conversion from a few years ago. First year of my engineering degree, my friend and I converted a 1993 Honda Del Sol to electric, using the guts of an electric forklift.

We got it going over 100km/h on used batteries our school donated to us. Unfortunately, there was a bit too much red tape and bureaucracy for us to get it on the road legally. That and we were poor university students who couldn’t afford new batteries, or the ridiculous amount insurance companies wanted to put it on the road. The project got scrapped after sitting in the backyard for a few years.

Fast forward to today, and we’ve both graduated and are working our “cushy” engineering jobs, and for the first time in our lives, we have some disposable income. We needed a new project to work on.

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Mini Go Kart Built In A Day

kart

The crew at the MIT student-run shop MITERS love their go karts, and when sitting around a pile of parts in the middle of the night on Saturday, there was only one thing to do: build a mini electric go kart in a day.

The parts for this were all taken from the jumble of parts lying around the shop: a few scooter wheels, some aluminum tubing, a 1×4″ piece of extrusion, a huge motor, and a ton of A123 cells were enough to ge tthe project started. They began by bolting the back wheel and motor to the aluminum extrusion and machining a simple steering mechanism.

The real fun began when they realized they could fill the aluminum extrusion with batteries, creating a 6S5P pack with the balance connectors and – after a few tries – the proper insulation. Combine all the parts with a Kelly motor controller and an old Brooks saddle, and the MITERS have a fairly light mini go kart that can cruise around the halls at about 15mph. Not much, but it was built in a single sleep-deprived night.

Video of the kart in action below.

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[Charles’s] Epic “Total-Recap” GoKart Post

charlesEVPost

If you’ve built an electric vehicle in the past few years, you probably owe [Charles] a couple of beers. Now you can feel more indebted to him after you read his 17,500-word, 10-part post covering everything you need to know about electric go-kart design. You’ll want to grab a sandwich to keep you company.

You probably recall the Chibikart from posts earlier this summer, which is one of an endless list of EV projects [Charles] has up his sleeve. He’s been teaching MIT students how to build EV karts for a while now, and this total-recap “2.00gokart” novel is [Charles’s] way of sharing the wealth. This is more than a simple how-to guide, though. Instead, it reads like a teacher’s edition of GoKarting 101, with a few brief and important histories, walk-throughs of how the class evolved, exhaustive links to vendors, graphs, videos, and plenty of reference and documentation.

If you have even the slightest interest in electric vehicles, do yourself a favor and give it a browse. There are a couple of videos after the break, and if you need some more motivation, check out the EV skateboard that uses a lot of the same parts.

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