I built a little 3 wheeled car to drive around my house. I built it just for fun and it would be great for kids. See the video below.
One day I challenged myself to build a small electric car that I could use to drive around my house. I wanted to only use supplies I already had so it would be free for me. I used the following materials:
scrap wood (2x3, plywood 3/8 thick)
wheels (3 Rollerblade wheels with ball bearings)
wood screws (1 inch, 2.5 inch)
Switch (from old vacuum)
windshield wiper motor (worm gear motor found for free)
Homemade wood wheel (connected to motor)
Battery pack, 12V (built from laptop batteries for under $3)
Door hinges (used for steering and motor pivot)
Rubber tie strap (for drive wheel)
saw (hand or jig saw)
Step 1: Frame and Wheels
The main T frame was built using 2x3s.
I only used screws to attached everything so that I could easily remove the screws and reuse them and the wood for another project. All these screws and wood have already been used for several projects.
For the Rollerblade wheel I screwed too pieces of 3/8 inch plywood to a spacer that was a little wider than the wheel. I carved the plywood so the wheels wouldn't rub. I then drilled a very straight hole and installed the wheel with bearings.
I screwed the door hing to the front wheel. I made sure the wheel axis was behind the hinge axis so the steering was stable.
Step 2: Motor and Batteries
I wanted to be able to disconnect the drive wheel from the ground. I put the motor and drive wheel on a hinge so that it could be lowered to the ground. When driving the cart the wheel pulls itself into the ground to get more traction. You can also pull up the handle to push the drive wheel into the ground. Also I didn't know if the homemade drive wheel and motor could take my weight as a load bearing wheel.
I built the drive wheel by cutting two 3 inch circles out of 3/8 inch plywood using my 3 inch hole saw. I glued these two wheels together. I then screwed the rubber tie strap into the wheel using 8 1 inch screws. I just screwed this wheel directly onto the motor. The motor only rotates at maybe 60rpm so this makes for a nice slow house car. This car was only designed to drive on very smooth floor like tile and hardwood. This is not a carpet car.
The batteries I used I made from 24 laptop cells. It is 12V and could run the car for about 4 hours. Please look at the instructable below.
Step 3: Test Drive
I spent all day driving around my house. This car would be great for kids. Our dog loves chasing the car.
I am really a kid at heart. I would drive to work (my desk in the living room). Then drive home (the bedroom). I was driving around and watching YouTube videos about electric cars.
Electric cars are really the future. I hope to get more money and build a larger car in the future.