Introduction: Electric Rubber Band Car
The vast majority of us like cars, especially when you can race with them.
In this instructable we propose you to make a car propelled by an elastic band, and with an electrical circuit we will add some lights. We will be able to work on concepts such as: series and parallel electrical circuits, led lights, energy sources, friction and energy transformation, among others.
- Car kit pieces cutted in mdf. This pieces could be laser cutted or by hand, it could also be made in other materials like expanded pvc or cardboard.
- Conductive tape
- 2 LEDs
- 2 AA battery holder with switch
- 2 skewer sticks
- 1 straw
- 2 AA batteries
- 1 rubber band
- Soldering iron(optional)
- Silicone gun
Step 1: Conductive Tape
Take the V-shaped piece from the kit and stick conductive tape on the top side over the entire V. Be careful with the conductive tape, it must be well attached to the car, in case of joints, it must overlap with the previous tape in a way that creates a good contact surface.
Repeat on the other side of the car.
Step 2: LEDs Connection
Take two LEDs and place them on the part marked as Front Axle of the V-shaped piece. For this step, the longer leg of the LED will go on the upper side and the shorter leg on the lower one, please make sure that they are in contact with the conductive tape on each side, forming a "sandwich" with the part between the legs of the LEDs.
Make sure that the LEDs legs are in contact with the conductive tape by using more conductive tape over the LED legs.
Step 3: Battery Holder
Take the battery holder and glue it, using hot glue, in the area marked as "Portapilas" on the V part of the car.
Fix with conductive tape the end of the red cable from the battery holder to the conductive tape on the top side of the piece.
Repeat but now with the black cable, on the other side.
Step 4: Assembly
Cut a piece of straw 8cm long, stick it on the underside of the V piece in the area marked as "Eje delantero".
Cut two pieces of straw 2cm long and stick them on the underside in the area marked as "Eje trasero", trying to get the straws as aligned as possible.
Step 5: Axles
To build the axles of the car, cut two pieces of skewer sticks 10 cm long.
Pass one of the sticks through the first straw on the rear axle, and before going through the second straw, pass the stick through the hole of the smallest piece of the kit. Finish this step by passing the stick through the other straw and the smallest piece will remain in the center of the stick.
Glue the small piece to the shaft with a drop of hot glue. Caution: Do not let the hot glue stick to the straws. And remember that it burns.. A lot!
For the wheels, first put hot glue on one end of the axle and, applying pressure, pass the axle through the center of the wheel. Do not let the wheel touch the straws, otherwise it will stick to it.
Repeat this with the rest of the wheels.
Step 6: Propulsion System
The final step is to place the rubber band. For this, pass one end of the rubber band through the hole in the front part of the v-shaped piece and take the other end and pass it inside the other. Pull the band until the knot is firm.
Step 7: Testing
To test the car, pass the rubber band under the battery holder and hook it to the central piece of the rear axle as shown in figure 9. Now you have to place the car on a flat surface and pull it back until the rubber band turns 5 or more times around rear axle, then release the car.
Step 8: Improvements
If the car happens to skid, add weight on the rear axle. Screws, nuts, stones or whatever material that goes into the car will do.
You can solder the components to the conductive tape at the joints to improve conductivity. Put rubber on the wheels so that they adhere better to the surface. Add weight to the car, this way you can increase the speed with which they work
Step 9: Good Luck!
Runner Up in the