This science project wil show you how to make a returning CD-ROM wheel.
This experiment is usually done with a tin can, but here you can see what is happening inside.
Step 1: Get 2 Used CD-ROM
Get 2 used CD-ROM's. These will be the 2 sides of the wheel.
Step 2: Drilling Template
Draw the following template with a CD-ROM. The 4 rounded holes will be needed to assemble the wheel. The 2 holes marked with a square are the elastic band holes for the interior mechanism.
Step 3: Prepare to Drill
Cut the template and stack it on top of the 2 CD-ROMs
Step 4: Drill the 6 Holes
Use a dremel to drill the 6 holes
Step 5: Drilled CD-ROM
You will get the following:
In yellow: 2 holes for the elastic bands
In red: 4 holes for the mounting screws
Step 6: Dowels
Get a dowel and masking tape.
Cut 4 pieces of dowel, each one the width of a masking tape as shown.
Step 7: Internal Mechanism
Get a heavy bolt and a piece of string. Attach the bolt with the string. This will be the internal mechanism that will make the CD-ROM wheel return.
Step 8: Assembly
Assemble the dowels to the 2 CD-ROMs with 4 screws.
Insert 2 elastic bands in the elastic holes and hold them with nails as shown. The elastics bands need to cross in the middle of the assembly.
Step 9: Test
Attach the bolt at the intersection of the elastic bands.
Gently roll the CD-ROM wheel away from you.
It will roll forward, stop and return back!
You can see the results on the following video: