Hackaday Prize Entry: Building A Car, From Scratch, Out Of Foam

Want an impressive example of what a few people can do in a garage? How about building an electric car, from scratch, starting with a gigantic chunk of foam?

The Luka EV from [MW Motors] had a few project aims: it should be all-electric, naturally, with a top speed of 130km/h or 80mph. It should have a range of over 300km, and it should look good. That last line item is tricky; it’s not too hard to build an electric car, but to make one look good is a challenge.

The design of the car actually started out as a digital file. A large block of foam was acquired and carefully carved into the desired shape. This foam is covered fiberglass, and parts are pulled off this fiberglass mold. This is a great way to do low-volume production – once the molds are complete, it’s a relatively simple matter to build another body for a second Luka EV.

With all the lights, accessories, windows, and trim installed, it’s time to put this body on a chassis. This was welded out of square tube and serves as a test rig that can be independent of the mess of fiberglass. In the chassis are batteries, suspension, motor controllers, and wheels loaded up with hub motors. It works well, even with one motor.

There’s a lot more to this project, including a great guide on building a road legal car in the UK. The team isn’t based in the UK, but it’s a much more friendly environment for ‘small series’ vehicles. The requirements are easy to meet – “have a horn”, for example – but there are a lot of them.

Already the car is beautiful, and that’s just with it sitting on a trailer. We can’t wait to see this thing hit the road.


The 2015 Hackaday Prize is sponsored by:

[Jay] Turns Over A New Leaf, Scores Batteries

[Jay] got a pretty good deal on a low milage Nissan Leaf battery. Unfortunately, it came wrapped in a wrecked Nissan Leaf. There are more and more electric cars on the road each year, and that means there are more cars coming off the road as well due to accidents. Electric cars are specifically designed to protect their batteries, so as we’ve seen before with Tesla vehicles,  a salvage car often will still contain a serviceable battery pack. [Jay] used this knowledge to his advantage, and walks us through his experience buying, testing, and dismantling Hoja, his very own salvage Leaf.

[Jay] set up an account on Copart, an auto salvage auction website here in the USA. “Live” online Auto auctions tend to work a bit differently than E-bay, so [Jay] walks us through the process of buying the car, and gives some tips for getting through the process. [Jay’s] particular car was delivered to him on a trailer. It had been rear ended so hard that the rear tires were not usable. The car was also electrically dead. Thankfully, the electrical problems turned out to be a discharged 12 volt accessory battery. A quick charge of the accessory battery caused the Leaf to spring to life – and display a ton of trouble codes. [Jay] cleared the codes with his trusty OBD II scanner, and the car was ready to drive, at least as much as a wrecked car can drive. It did move under its own power though – with the rear end riding on dollies.

Now that the battery was known to be good, [Jay] set about liberating it from its crushed Leaf cocoon. Nissan’s service manual assumes one would be doing this with a lift. [Jay] had no such luxuries in his driveway, so he used 3 floor jacks to lower the 600 lb battery and dollies to pull it out from under the car.

Click past the break for the rest of the story.

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Earth Day: Electric Vehicles

Electric vehicles are the wave of the future, whether it’s from sucking too much oil out of the ground, or because of improved battery technology. Most internal combustion engines are unsustainable, and if you’re thinking about the environment – or working on an entry for The Hackaday Prize – an electric vehicle is the way to go.
Here are a few electric vehicle projects that are competing in The Hackaday Prize that show off the possibilities for the electric vehicles of the future.

An Electric Ninja

Motorcycles are extremely efficient already, but if you want a torquey ride with a lot of acceleration, electric is the way to go. [ErikL] is hard at work transforming a 2005 Ninja 250R into an electric vehicle, both to get away from gas-sipping engines and as a really, really cool ride. Interestingly, the battery technology in this bike isn’t that advanced – it’s a lead acid battery, basically, that reduces the complexity of the build.

And They Have Molds To Make Another

Motorcycles aren’t for everybody, but neither are normal, everyday, electronic conversion cars. [MW Motors] is building a car from scratch. The body, the chassis, and the power train are all hand built.

The amazing part of this build is how they created the body. It’s a fiberglass mold that was pulled off of a model carved out of a huge block of foam. There’s a lot of composite work in here, and a lot of work had to happen before digging into the foam; you actually need to choose your accessories, lights, and other bits and bobs before designing the body panels.

While the suspension and a lot of the mechanical parts were taken from a Mazda Miata, the power and drive system are completely custom. Most of the chassis is filled with LiFeMnPO4 batteries, powering four hub motors in each wheel. It’s going to be an amazing car.

Custom, 3D Printed Electric Motors

If you’re designing an electric car, the biggest decision you’re going to make is what motor you’re going to use. This is a simple process: open up a few catalogs and see what manufacturers are offering. There’s another option: building your own motor. [Solenoid] is working on a piece of software that will calculate the specifications of a motor given specific dimensions. It will also generate files for a 3D printed motor given the desired specs. Yes, you’ll still need to wind a few miles of copper onto these parts, but it’s the beginning of completely custom electronic motors.

Autonomous Vehicle-Following Vehicle

Humanity has taken one step closer to Skynet becoming fully aware. [Ahmed], [Muhammad], [Salman], and [Suleman] have created a vehicle that can “chase” another vehicle as part of their senior design project. Now it’s just a matter of time before the machines take over.

The project itself is based on a gasoline-powered quad bike that the students first converted to electric for the sake of their project. It uses a single webcam to get information about its surroundings. This is a plus because it frees the robot from needing a stereoscopic camera or any other complicated equipment like a radar or laser rangefinder. With this information, it can follow a lead vehicle without getting any other telemetry.

This project is interesting because it could potentially allow for large convoys with only one human operator at the front. Once self-driving cars become more mainstream, this could potentially save a lot of costs as well if only the vehicle in the front needs the self-driving equipment, while the vehicles behind would be able to operate with much less hardware. Either way, we love seeing senior design projects that have great real-world applications!

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Mini EV Tractor

Odd-Looking Mini EV Yard Tractor Is Made From Plywood And Bike Parts

Mini EV Tractor[Ian] likes to build small Electric Vehicles and his most unique project is certainly this yard tractor. During the design phase of the project [Ian] came up with a few requirements to ensure that this vehicle would be useful around the house. First, it had to be maneuverable in tight spaces. This was accomplished by the short wheel base and small diameter front-steering wheels. Next, it had to get great traction as leaving torn-up grass around the yard was not going to cut the mustard. Four mountain bike drive wheels used in the rear double the traction while at the same time distributing the friction over twice the surface area of the grass. To increase the traction even more, the rider’s seating position was intentionally put directly over the rear wheels.

The frame was kept simple by using plywood as structural members. Two 40Ah 12v batteries are set low between the front and rear axles and power the 4 DC drive motors. The motors are connected to the axle by means of sprockets and chains which results in a 36:1 reduction. That’s a large gear reduction and limits the tractor to a top speed of 12 km/h (7.5 mph). Bike tires front and rear were used because they are easily available and are super low-cost. And of course, a tractor wouldn’t be complete without a trailer hitch to tow around plants, rocks, wood or any other general yard debris.

[Ian] makes plans for his mini EV tractor available on his website. If your kid is envious of this electric tractor, maybe you can make him one of these

 

Self balancing chopper

Self Balancing Vehicle Inspired By Bicycles Of Yesteryear

[XenonJohn] is not a newcomer to the world of self balancing vehicles. He was part of the Medicycle team and a semifinalist for The Hackaday Prize. Working on the Medicycle had exposed some opportunities for improvement of the design, the most significant being the single wide wheel supporting the vehicle and rider. The unicycle design was more difficult to learn to ride than that of a two-wheeled nature. [XenonJohn] wanted to make an improved self balancer and this new one will have two wheels that are independently controlled.

Although the finished product looks like it started with a bike frame, the self-balancer’s frame is actually completely custom. The handlebars and banana seat were purchased new as aftermarket parts for old-style bicycles. Powering the two wheels is a pair of 24v brushed motors, conveniently each one came with a 6:1 reduction gearbox pre-installed. The wheels are a complete compilation of parts not intended to go together. The BMX bike rims were laced to mountain bike front hubs. The hubs have provisions for a disk brake but [XenonJohn] mounted a large toothed pulley there instead. A belt then connects the drive motor gearboxes to the pulleys completing the drive train.

The LiFePO4 battery kit was purchased off eBay and puts out 24v and 15AH using eight cells. These batteries alone were a hefty percentage of the projects cost, costing nearly $300. Controlling the vehicle is an Arduino Mega that makes use of the FreeSix IMU library. The Mega receives inputs via I2C from a Sparkfun SEN-10121 board that contains both accelerometers and gyroscopes along with turn switches connected to the ‘brake’ levers on the handlebars. The Arduino then sends commands to the 25 amp Sabertooth motor controllers to keep you balanced as you buzz around town.

Video below.

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The Marriot Chariot Hauling Ass

[Harrison Krix’s] Marriott Chariot

Atlanta’s Mini Maker Faire had plenty of booths to keep visitors busy, but the largest spectacle by far was the racetrack smack-dab in the middle, and you’d be hard pressed to find a more eye-catching contender than [Harrison Krix’s] vehicle: the Marriott Chariot.

If [Krix’s] name looks familiar, that’s because he’s the master artisan behind Volpin Props, and is responsible for such favorites as the Futurama Holophonor replica and the Daft Punk helmet. (Actually, he made the other one, too).

The Chariot is yet another competitor in the Power Racing Series, an event that keeps popping up here on Hackaday. [Krix] drew inspiration from this Jeep build we featured earlier in the summer, and went to work sourcing an old plastic body to get started. The frame is 16 gauge square tubing, with a custom motor mount machined from 3/16 steel. After welding the chassis together, [Krix] chopped up a small bicycle to snag its head tube and headset bearings. A pair of sealed lead acid batteries fit horizontally in the frame, providing a slightly lower center of gravity.

[Krix] has a keen eye for precision and his build journal shows each step of his meticulous process. But, you ask, why “Marriott Chariot?” and why does the car look like someone threw up a kaleidoscope? Read on beyond the break, dear reader, to learn the Chariot’s origin and to see a video of it winding around the track.

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