So, this is the first real
step of of the build! This is where parts and materials are collected. You're still advised to read through everything first to see what you already have, can scrounge, or otherwise think can be bypassed. This is the "master list" of parts which was convenient to order through the Internets - it is not literally every part, and some things such as one-off screws will need to be sourced by you at a hardware store or similar.BIG BLUE SAW
The most important and first on the list, since they will provide you with the appropriately-designed metal plate parts which fit together into a Chibikart! There are 3 files which I have included at the bottom in a compressed folder:
0.250" 6061 Aluminum panel
0.125" 6061 Aluminum panel
0.125" PETG / Polycarbonate panel
Upload the files and obtain quotes (making sure to select the correct material), then add to cart. It should turn out to be about $400 (as of May 2012) - $140 for the 1/8" aluminum, $260 for the 1/4" aluminum, and $20 for the PETG panel. If you want to spent a little more, for $80 you can get the plastic panel made using polycarbonate instead - it is more impact resistant.
You can also make it from wood. If you do so, I recommend a non-grained wood fiber product like MDF or Hardboard - they are less likely to splinter and crack at the surface.MCMASTER-CARRMcMaster-Carr
is one of the largest industrial supply houses in the world, and the best part about them is that they deal directly with you. Their site has been hailed as a great example of link-rich navigation in the past (when it was a literal wall of text
) and the new interface for finding common part with tons of variations (e.g. nuts) is even better.
There's so many things to get from McMaster that I've attached the BOM as a text file. Right now, there's not an easy way to just drag-and-drop that into an order, so you will have to do some copy-paste legwork.HOBBYKINGHobbyKing
is pretty much the premier supplier of East Asia sourced R/C model parts these days. They have many lines of motors, batteries, connectors, wires, and accessories. What we will be needing from them is the drive motors and some wiring products. There is also an extensive BOM from Hobbyking, so I've also included it as a text file.SURPLUS CENTER
If you ever need parts for your tractor or semi, Surplus Center is the place to go. They are a surplus parts and equipment vendor - as such, if you ever need things like large DC/AC motors, giant sprockets, whole engines
, etc. they should be at the top of your list too.
I purchased the centerpiece of Chibikart - a Troy-Bilt lawn mower seat, from Surplus Center. It is part number 1-3289
I also purchased the motor sprockets and a small amount of #25 drive chain. The motor sprockets are P/N 1-2742-12-A
QTY 2, and the #25 chain is 1-1163-25
QTY 1. You will also need at least two
#25 master links: 1-1087-25
Along with many other similarly named scooter parts vendors such as Monster Scooter Parts
and the aptly-named Electric Scooter Parts
, TNC Scooters
is a vendor of import-grade shady small vehicle parts. You can build most of a vehicle just using those vendors. However, TNC is the least expensive source of a very rare small vehicle part: the throttle pedal
. We need this - their part number THR-101124
.eBay - BOBZHANGXU and his magic e-bike controllers
Buy 2 of these 24v 250W controllers
and do not ask questions.
As you can probably see by now, there is no one magic dealer for all small vehicle parts. This may very well be my cue to corner the market, but before I can get all my stock in, you will have to shop around. Chibikart's controllers are nicknamed "Jasontrollers
" - pretty much because they have no official name, nor an official vendor.
This nice and very helpful dude (not kidding - I've done business with him off-eBay several times) is based in Guangdong, China and is the only vendor of a small vehicle-optimized sensorless brushless motor controller that doesn't suck
. Hopefully there will be better things coming down the pipes here at MIT to be publicly released soon, but in the mean time, Bob-jason is all we have.
Why sensorless? If you read through the Scooteructable
you might notice that I wail on sensorless drive several times. I decided that having to wiggle yourself possibly during starting is acceptable compared to instructing people on how to properly assemble, timing-adjust, and hook up a set of Hall-effect rotor sensors to hobby motors. This is something I have personally instructed other people how to do, and it is a very painful process.AMAZON
Since when did Amazon become an industrial supplier? (Answer: since Amazon Supply
Well, we'll be needing some random other parts from them, like the main power switch. The switch is a "Hella" style battery cutoff switch for automobiles.
These come in 2 flavors: Real (Hella brand)
, which features silver contacts, pure copper conductors, and heavy ABS and nylon construction, and Shady
(knockoffs of an older Hella design), which uses raw brass (copper if you're LUCKY!) everything and is made of... I'm not sure what, but it smells weird. You can find other variants of the knockoff by searching for "Battery switch" or "Master switch".
The decision is yours - the mounting plate for the power switch contains both hole patterns. You need 1.Fuse Holder
Chibikart's electrical deck is designed to use a "AGU" inline style fuse holder. This is commonly available in car audio shops and electronics retail stores. An example is here
The battery for Chibikart is twoK2B12V7EV 12v 7Ah lead-acid replacement modules
. They are lithium ion batteries hiding in a box with a controller that lets them pretend they are lead-acid batteries. Nifty, huh? For more information on these, I did a full teardown of that particular battery
- which is why I chose it in the end - on my site.
Short story: the answer to "Why didn't you just use Hobbyking lithium polymer batteries?" is no.Bearings
Four FR8ZZ type flanged radial bearings are used for Chibikart's steering. My favorite Chinese bearing front, VXB (because all legit bearing manufacturers have cool 3 letter names like NSK, SKF, NTN...) sells these as p/n KIT7578
. However, the same goods are also sold on Amazon, so you may prefer to just consolidate an order.
Alternatively, just searching "FR8ZZ" on eBay brings up tons
of results, many of which are cheaper per unit and offer free shipping . Sort by Distance First to avoid the ones that are straight from China because they will take eons to ship. My personal favorite eBay vendor for bearings of indeterminate origin is USABearingsAndBelts
a close second, though they do not have the FR8ZZ type.BATTERYSPACEBatterySpace
is one of those things made possible only through the Internet. They're essentially a front company for Chinese battery vendors. This is totally not a bad thing - in fact, I love them. From Batteryspace, select a 24v charger for lithium iron phosphate batteries. This model
(CH-L2596N) will charge the above K2 bricks in an hour flat.
You can find downmarket 1.5-2.0 amp 24v scooter chargers on Amazon for $20-30 if you are inclined to wait longer, but I think spending the extra $30 to have 66% less downtime is worthwhile.
Incidentally, BatterySpace also has their own line of mysterious SLA replacement bricks
. I have not touched these in person, ever, nor peered inside one, and their discharge rates seem awfully low, so I would stay away from them for now.YOUR LOCAL BIKE SHOP
I sourced many brake parts from Cambridge Bicycle, the bike shop across the street from our building, and they were immensely helpful in helping me sort out bike jargon so I could direct everyone else correctly. You need several generic bicycle brake parts:
6mm Barrel Adjuster and 6mm brake cable anchor bolt. These are commonly found in road bike caliper brakes. Example barrel adjuster and anchor bolt (print those out and show them pictures if you have to!). Or just buy it from Amazon.
2x 4 foot brake cables and sleeves. At least one end must have a 7mm molded nipple (the round thing)
2x road bike brake pads. Get the smallest, most rectangular one you can, and it must have a 6mm stem.