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.
As I interpreted their project log, in the end they ditched the alternator and used another motor, right?
yes.
Heh, I just built a go-kart using the 10″ Harbor Freight tires. They are indeed impressively soft. I guess that’s what you get for $6.00!
Woah, THEY MADE THE GEARS? They made their own gears on a frigging bridgeport? Thats awesome
Rob is an impressive man, they are not normal gears either!
That bridgeport video is insane. https://vimeo.com/102252226 Is ‘reeving’ the name of this process?
Making gears is one thing, straight cut gears are something you do in first year of machinist training. The impressive bit is that they did helical cut.
This is one helluva build log, that’s a lot of detail packed in there. I need to build one of these for the kids.
I’m fairly sure they just wanted to make gears and then the kart sprung up around the gearbox, which was ad-hoc designed to the gears….
I too thought the gears were impressive!
Does anyone know of any series like this in the UK?
Hey! Thanks all
It turns out that the powerwheels racing cart actually fairs better off-road than on!
http://vimeo.com/107417811
[vimeo 107417811 w=500 h=281] CHIBI ATOMIC THING ventures outdoors from Dane Kouttron on Vimeo.
so if you’re custom CNC’ing the entire driveline, building custom wheels/axles/steering box and brakes, pulling a motor from eslewhere and mating it all to a welded steel spaceframe, are you actually doing anything “power wheels” at all?
It’s like guys showing up to LeMons and using millions of dollars of CAD/CAM to turn $500 worth of raw steel and aluminum into an entire vehicle and still claiming to be with the spirit of the “$500 junk car” rules.
After you’re using nothing (in some cases, not even the body but a fiberglass repro) you’re just an electric go kart using a small footprint.
Power Wheel racing needs to maintain at least some of the original vehicle. Preferrably the parts that break when the vehicle is overpowered, overdriven, etc. Stock wheels and body must at least be mandatory. Preferrably stock axles too, then when someone overdoes the power, they fail in spectacular and hilarious ways.
This exactly. They put on their build page a pathetic lie saying the car cost less than $300…. sure. $10,000 in parts and unlimited engineering time and tools, when they are done its worth about $300 in scrap metal.
the cost pays to produce the videos and the documentation and the plans, these are the “products” of the money spent
the “value” of the prototype unit is completely arbitrary because it is not the goal of the project
I suppose this falls under the “I ain’t even mad” rules clause. There’s also an option where, on the day of the event, officials can offer to buy your car at $500 – and you have to take the offer. So don’t sink $10,000 into it if you don’t want it bought out at firesale price.
the $10,000 was “sunk” into the production of the plans and the documentation
if you can make one AND YOU KEEP GOOD NOTES, then you can just make another
I guess it’s cheating if I make something from the pieces of metal stock they sell at home depot because it takes some REALLY EXPENSIVE equipment to bend the metal into those forms
If you want to see this thing’s “competition” slash compatriot, check the earlier Hackaday post at http://hackaday.com/2014/09/30/the-chibi-mikuvan-or-a-power-wheels-with-a-ford-fusion-battery/
Great efforts were made towards the documentation of these vehicles, design through deployment, for the benefit of other future builders.