A couple of months ago me and my dad decided to build an electric car for my son. It's been a long and difficult task, but in the end, we are very satisfied about how it works. So here is my second instructable!! It's not very detailed beacuse we had not much time to build, birthday was coming, but (maybe) it can give some ideas to other builders.
I already had laying around unused an electric bike kit taken from my old electric bike (when my son grew up it became unuseless), and this is how I used it.
Hope you enjoy this!
Step 1: Material Needed
It'a big project... and complicated... but the most important part I've used are these:
-iron square pipe (I used 3cmx3cm) for the chassis
- 350w bike conversion kit. You find it on ebay, it's common and come with the controller and a accelerator handle. the motor is already geared and make everything simpler. you can find it cheaper than that
- crown gear (I used a pack of 6 from a bicycle rear transmission because I didn't know the speed of the motor, in the end I used only the bigger one)
- a couple of sealed batteries. I used 2x12v 14A
- brake caliper used in mini moto
- brake disc
- rear axle : I used a rectified 16mm axle
- 16mm bearing block x2 for the rear axle
- wheels. I used these and I'm not happy about that. Those were the bigger I found for that price but are cheap and too little
- 2 thrust bearing
- 2 pieces of threaded rod for the front wheel
- metal braided cable (to build the steering system)
- led for the headlights
- rocker for the headlights
- tripolar diverter for reverse
- buzzer for reverse
- 1 button for the horn
- a mountain of plywood (I used 8mm for the body and 20mm for the flooring)
- a bucket of screws for metal anf plywood
- a log to carve the curved part of the body
- 8 hinges
- plexiglas for the windscreen
- an incredible amount of time
Step 2: Building the Chassis
After a few measurement we decided that 120cmx80cm was big enough for 2 kids (my son is 120cm tall), and there was still some space behind the seats for the victuals (my son is panino-addicted...)
The frame is formed by 2 shaped bars (they go front to back and their middle portion is angled so that the front wheels has room enough to turn), topped by 4 bars (left to right) . Of these last four the inner ones are soldered above the junction of angled piece and the first and the fourth are on the edges. Then there is a fifth one that support the front wheels.
The black square in the wonderful rendering is the motor support.
Rear wheels, transmission and brake disc are secured to the axle with big pins.
Step 3: Pedals and Batteries
Under the bonnet there is room for batteries, motor controller and pedals.
We decided to put batteries in the front to prevent front wheels from slipping, because the rear axle has not a differential.
The gas pedal is connected to the original handle from the bike kit with a cord. I've kept is as original because it has inside an hall sensor that I could not find elsewhere.
the brake pedal work with a bowden cable that goes under the floor to the brake that is on the rear axle.
This pedal is also connected with a metal wire to a rod on the dashbord that can be pulled and blocked as handbrake.
Step 4: Electrical Connections
In the image you can see how to connect the reverse switch.
the system work with 2 12v batteries wired in series.
they are connected to the recharge inlet (that is under the hood) and to the controller through the main switch (with a key). One of the batteries is used for headlights (parallel), horn and control lights.
When the reverse is activated buzzer and warning lights turns on.
Step 5: Body
We choosed the jeep style because it's beautiful. No it ain't true. It was simpler.
There are only four curved parts, that we made with the log. We put it on the lathe and then cutted in 4 parts
Wheel arches are not rounded (well, only a bit). Here I made the biggest mistake: the wheel is too near to the arch. They don't touch, but they have not the right look.
Doors are attached with hinges, and they have a magnet and a little door latch(from inside)
The bonnet has two hinges and a magnet. A lever under the dashboard must be used to open it.
The trunk has hinges and latches too.
The windscreen is built with 3 layers of plywood with plexiglas inside.
Step 6: Finishing and Details
The steering wheel is made with plywood layers, one under for support, the main one cutted with my homemade electric jigsaw and the top one (thinner) is chamfered with the router.
Seats (sorry I have no photo) and dashboard are covered with synthetic leather.
Headlights are homebuilt with the upper part of 2 water bottle. The led (12v 5w) is in the cap, the edge of the bottle parable is blocked with a plywood ring on the outside.
I have painted the body with two coats of undercoat and three of red gloss paint.
here the youtube video