We wanted to make a project that is low cost and fairly simple to do. A fun project for everyone that took a lot of trial and error to work properly. The idea for this project came from Bhaskara's wheel. We know perpetual motion machines are not real but the concept behind Bhaskara's wheel could essentially make the wheel spin longer, which is what we did.
- a bearing (maybe 2). Got ours from an old skateboard
- an axle for your bearing to rotate on
- a light wheel (we used styrofoam a foot in diameter)
- test tubes (the longer the better)
- duct tape
- x-acto knie
Step 1: Find a Bearing
Finding a bearing for me was fairly simple. I knew there was an old skateboard in my garage so I found it, took off the wheel, and popped out the bearings. Took two for good measure. If the bearing you find doesn't spin too well, don't worry, there are many youtube videos that show how to properly clean them.
Worst case scenario is you can't find a bearing and so you could go to your local skateshop and find a whole pack of 8 for around 10 dollars. They might even have old bearings laying around that you could ask for.
Step 2: Find Some Sort of Axel
Finding an axle for your bearing(s) to spin on should not be very difficult. If you're using a skateboard bearing the diameter of the center will be 5/16 of an inch. We went to the hardware store and bought a 5/16 wooden dowel for $0.96. if your using a different bearing just measure out the center and find an axle that suits your needs.
Step 3: Get Your Wheel.
We wanted something that was lightweight and easy to work with. So we went to Michael's and bought a styrofoam wheel that was an inch thick and a foot in diameter. We bought two for trial and error purposes and to use at the end to show the difference in how long a normal wheel spins verses the wheel that we modified.
Step 4: Find the Center of Your Wheel.
Doing this takes some simple measurements. If you're unsure how to do this you could always eyeball it in hope for perfect precision or follow the steps that we did here.
Step 5: Cut Out Spot for Bearing
Place the bearing directly over the center mark that you made in step 4 and trace the circumference with a marker. Use an x-acto knife to cut out the inside of the circle you just made. be sure to cut on the inside of the line you created, that way the bearing fits snug inside the wheel.
Step 6: Divide the Wheel Equally
Using a protactor we measured out every 60 degrees and drew a line, this divides our wheel into 6 perfect sections which is where we will be placing our test tubes of water.
Step 7: Fill Your Test Tubes
We had limited supplies so we asked our science teachers for some test tubes and they let us use them; I'm sure you can do the same. this step takes a lot of trial and error. The goal here is to fill your tubes with the right amount of water so that the weight from your water is enough to keep the wheel going but not too much to where it has the opposite effect and slows your wheel down. we found that taking 2 test tubes and filling one of them just over half full and taping them together with duct tape gave us the length and weight we needed. your test tubes may be different, like i said, there is a lot of trial and error in this step.
Step 8: Secure Your Test Tubes to the Wheel
This goes hand in hand with the previous step and also requires trial and error. The goal in this step is to find the right placement for the test tubes so that the water is able to give the wheel the momentum it needs to stay in rotation. For this step you can use duct tape or zip ties. zip ties are more aesthetically appealing but the duct tape seemed to work a little bit better.
Step 9: Add a Simple Wheel to the Axle.
This step is optional but to show everyone that your wheel works you can repeat steps 1-5 and add that wheel to your axle. This way you can spin both wheels simultaneously and watch as the wheel you modified spend longer than the stock wheel.