Chibikart: Rapid-Prototyping a Subminiature Electric Go-Kart Using Digital Fabrication and Hobby Components

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Chibikart! is a very small yet powerful and maneuverable 2WD electric go-kart that you can build using off-the-shelf industrial and hobby components and digitally fabricated frame parts. Using modern lithium ion batteries and brushless permanent-magnet electric motors, Chibikart can accelerate its diminutive 34" x 26" frame with you attached to speeds of 22 miles per hour.

The design is intended to be extensible according to your own requirements, using an industrial slotted framing system typically used to construct prototype machinery called 80/20. Precision-cut aluminum frame parts are intended for fabrication via abrasive waterjet machining services and can be assembled like a puzzle. Many parts can be sourced from your local hardware store or home improvement store. Some fabrication using common garage and shop tools such as drill presses, hacksaws, bench vises, and belt sanders is required, but there are no parts that require conventional machining such as milling or turning!

The final product is intended to highlight the level of sophistication available to modern makers and builders who may not necessarily have access to a conventional machine shop or collective such as a hacker / makerspace. Especially for students and minors, access to machine tools may be difficult or nearly impossible in our age of overabundant safety and caution. It is designed to show that the world of amateur and hobby engineering extends far beyond Home Depot and hardware stores - something which is generally unknown to many people who may be interested in pursuing engineering as a career, or aiming to explore it as a hobby.

This build will focus extensively on purchasing parts through online industrial supplier catalogs such as McMaster-Carr, specialty & hobby suppliers like Surplus Center, HobbyKing, and digital fabrication houses such as Big Blue Saw. Having access to these electronic resources, which really only became possible in the past few years, will facilitate students and hobbyists in producing higher quality and more awesome projects.

The resources alone, in my opinion, are all that most readers of this Instructable will need - it is often the case that many people who want to build things and know generally the approach they need, cannot proceed because of a lack of proper resources, whether it be tools or materials. In this case, this Instructable is perhaps more useful as another resource and technique guide, similar to my previous writeups on selecting electric vehicle power systems and building hub motors.
samkel93 years ago
Looks great. Can you tell me roughly how much it cost for the whole thing? I'm kinda young and would love to do this but don't have a lot of money.
teamtestbot (author)  samkel93 years ago
Please spend some time and read through at least some of the pages. The information you are seeking is found in step 2.
I'm not sure you uploaded all the files needed for this build at the end of Step 3 - when I downloaded them and uploaded them to Big Blue Saw, 2 files seemed to be almost the same, with the steering yoke missing from one of them. Lots of the pieces (like the brake pieces and corner brackets) also seem to missing and are not found in the zip. Perhaps you accidentally uploaded a duplicate?
teamtestbot (author)  DoctorFedora3 years ago
Yup, I definitely accidentally cloned two file versions.

Just fixed it - there should be a 0125 and 0250 aluminum, and then a 0125 polycarb/wood/PET/what-have-ye.
Since many people like me are not expert cad modelers could you share your plans?
teamtestbot (author)  diabetishead3 years ago
Please refer to Step 3 for the DXF drawings (submittable as-is to Big Blue Saw) and the last step for the Autodesk Inventor original models.
RobertW39 made it!1 month ago

Super fun to make and drive!

DIYPro05053 months ago
Can someone please tell me what is the exact name and model of the motors or can someone give ma a direct link.
KNEXBeast2 years ago
Did you make the drawing with Autodesk Inventor?
gbmaster1372 years ago
is there a way to connect 4 motors and a reverse function?
So the real question is:  How many instructables can you write before having to replace your keyboard?

My bet is 3.
teamtestbot (author)  killersquirel112 years ago
Incidentally, I got a new USB keyboard soon after writing this because my laptop's keyboard went out.
blkhawk3 years ago
I have to say that yours is one of the best documented projects in this site. Kudos to you!
smtkl3 years ago
what this motor nominal torque?
mochimaster3 years ago
I'll be building an electric go kart too this summer, except with a more rudimentary design, and bigger wheels.

But your design will definitely help me. Very neat.
fluxuss3 years ago
This is awesome! I guess MIT likes DIY'ers, did you get a fund for the project from school? Anyway, well detailed instructables like always. Keep it up!
teamtestbot (author)  fluxuss3 years ago
Free stuff, lab work, and/or graduate student stipend. What's the "fund from school" you speak of...
sprout_less3 years ago
Have you done FIRST robotics? Because everything looks very similar to the robot I have built.
teamtestbot (author)  sprout_less3 years ago
I did in high school (I founded FRC 1771 in 2005/6) and 80/20 is indeed a very popular framing system for FIRST bots, but none of ours used it. The framing methods seem to all converge on the same look...
ben_k3 years ago
Really incredible project and writeup! I saw some of your other vehicles at the Atlanta mini Maker Faire, and they have served as excellent inspiration for the somewhat absurd e-scooter I'm building now. I can't wait to join your collegiate silly vehicle team in the fall.

note: Some of your image notes seem to be duplicated onto consecutive pictures
teamtestbot (author)  ben_k3 years ago
I feel like that's an Instructables derp. The text editor is extremely buggy...
I'm left thinking the only thing missing with this instructable is a video of the kart in operation.
teamtestbot (author)  dirty_valentine3 years ago
Keep reading :)

Demonstration videos are in Steps 43 and 44.
Nxtfari3 years ago
Quite literally one of the most amusing and detailed reports i have ever seen on Instructables. Very nice!
emissary423 years ago
This is one of the most detailed reports I've ever seen on Instructables. Here's to hoping we start to see swarms of micro EV's like this at Maker Faires & cons.
Jamo_G3 years ago
Awesome project and an amazingly detailed report. Gonna have a good time strolling this guy around campus :)