My son's rubber band powered balsa plane crashed and was too badly damaged to be fixed. We opened our craft stuff box and used what we had on hand to make this rubber band powered car.
Step 1: Materials and Tools
The tools are simple:
Pliers/ wire cutters
Patience (I know its not a tool but definitely a required skill!)
Materials we used ( the same general properties are the only requirement for the pieces. Our goal was to use only what was readily available out of our recycle bin or craft supply box.)
Rubber band powered propeller w/ its mount
A dowel approximately 8 inches long
2 Zip- ties
2 Push-pop bases and handles (these we used as our back wheels and axles)
1 straw with larger diameter than the push-pops rod.
2 Juice bottle lids (front wheels)
6 inch long piece of smooth plastic tubing (to hold out the small wheels)
Rigid plastic body (we used the container for glow stick necklaces)
A wire coat hanger
Duct tape (a million and one uses!)
Step 2: Basic Design and Wheels
I had intended to put the larger "wheels" in the back but my son thought it would look better them in front. I also thought if I reversed the propeller it would work as a pusher. It turned out that the propeller was designed as a puller type and only worked efficiently when used that way.
A layout of materials to determine spacing is recommended to prevent re-working.
Safety first!!! Drill carefully, trying to keep the bit perpendicular to the surface being drilled. Be sure that the surface beneath your project is safe to drill on/ into.
Drill holes in the center of your large wheels, cut a straight piece of hanger for an axle,.
Insert in the car body, attach the large wheels, then washers and zip-ties cut to fit.
Smaller wheels, (push-pop pushers):
Drill the hole in the body slightly larger than the push rod.
Attach the small wheels to both end of the rod and center it in the car.
Now cut the straw to fit evenly on both sides of the small wheel axle to act as spacers to keep the wheels from sliding up against the car body.
Step 3: Prop Positioning
Ensure the propeller will clear the ground and the body will not drag when the wheels are installed
Make a cut in the body slightly larger than the prop support and insert the your dowel into the support. Now align the dowel along the body as straight as possible. This will help the car drive in a straight line. Secure it in place with duct tape.
My son thought it was cool to have the large wheels in the front so the prop was far enough away from the ground to not be a problem.
The rubber band will pull tight on the prop so it may tilt back. To prevent this my son came up with this ingenious little bent piece of hanger to hold it down. (I was planning on using duct tape, so I compromised and used both.) Position this bent -S piece so it hooks over the propeller support just below the rubberband attachment hook and attach the lower end of the bent-S to the front of the body and secure in place with duct tape.
Step 4: Test Drive!
Stretch your rubber band from the prop to the back end of the dowel and secure in place with.......(you guessed it!) duct tape.
Wind the rubber band until it starts to knot up, then it should be tight enough to let the prop have a good pull but not bind up against the dowel.
Total work time: approximately 1 hour with fine tuning and adjustments.
Check out our test drives. (The second vid is a better demo but check out my little dude's reaction on the first vid, it was classic! He seemed surprised it worked!)