Chibi chibi chibi…
I’ve seen that four 100mm hub motors in a pair of roller skates can definitely keep a person going and act as a cruise assist, but can they be made powerful enough to drive a go-kart too? In stand-on vehicles, the kick you perform to start yourself off balancing actually imparts a significant amount of kinetic energy – thus, the motors don’t have to work as hard, but this is clearly not available in a sit-down vehicle. Chibikart was a build to both test this hypothesis and to have a go-kart which fit in the front half of tinykart (Let’s face it - that’s the actual design motivation here). The 100mm hub motors were modified slightly to yield more potential power. This build was also a chance to use up some possible “production hardware” for the 100mm motors that I had made as an experiment into Internet-sourcing machined parts.
The conclusion: Not bad all, actually. Chibikart doesn’t quite have the kick of an indirect-drive electric kart with a more powerful hobby class motor, but it can get up to a pretty brisk pace – and of course, there is almost no drivetrain loss, and it’s 4 wheel drive!
Responding to Internet commentary that the design was totally unbuildable by most people (which is true, due to the level of machine work involved in the hub motors), Chibikart’s design was eventually evolved into the Democratic People’s Republic of Chibikart. This design was spawned to take advantage of modern digital fabrication resources and could be built completely without machine tools. I built the design as a prototype of sorts for 2.00gokart in 2013. As for Chibikart itself, it was eventually retired but the frame recycled into BurnoutChibi.
Here’s Chibikart’s build thread.
|Drivetrain||4 wheel direct drive|
|Mechanical||80/20 1″ extrusion and 5052 aluminum frame|
|Motor||Custom 100mm wheel hub motors, 150W peak ea.|
|Controller||4 350W Jasontrollers|
|Battery||32v 9Ah Lithium iron phosphate battery pack (10S2P)|
|Curb Weight||40 pounds|