Electric Go-Kart (2020)
My son wanted to build a go-kart. I suggested we buy a kit since that would give us the pleasure of building it and would have all the integration and testing already done. He wanted to design the whole thing… so we did.
Early prototype (age 9).
Six years later, with his OnShape CAD experience from robotics, he developed a more detailed design.
then got to work fabricating the frame, seat, and assembling the wheels:
The seat is even adjustable. The steering column is a steel pipe terminated with a pipe flange, and the tie rods connect to one of its bolt holes.
Along with a steering wheel from an old video game and a surplus pedal from BMW, we got a rolling chassis:
We chose a 48v DC motor and used four 12v UPS-style batteries for power. The most challenging part was finding sprockets of the same pitch that matched the metric motor output shaft and the 1" rear axle. The motor mount allows for adjustment of the drive chain tension.
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The motor controller includes regenerative braking but we also added a disc brake. Other finishing touches include an on/off key, voltage meter, and forward/reverse toggle. We did not try to calculate it ahead of time, but this combination of motor RPM, sprocket ratio, and tire size gives the go-kart a maximum speed of about 35mph! When you are inches from the ground, that feels plenty fast!