Physics Rotation Pulley

thingiverse

This project transforms a MakerBot filament spool into a physics rotation pulley that showcases rotational inertia and simple pulley systems with weights in classrooms. The large size of the spool/pulley makes it ideal for these labs as it is massive and has a larger radius than typical physics pulleys, providing a cheaper alternative to purchasing large pulleys like bicycle wheels while also reusing empty filament spools. The 3D printed clamps are designed to fit over the outside of the MakerBot spool and clamp into the notched sections in the center. The clamps hug the outside of the wheel, bridging the gap between the two edges. Although it takes a little bit of bending to put them on, the clamps should fit securely due to their snug design. The Sector Bridges extend the groove all the way around the wheel, preserving the pulley's curvature by spanning the gap between the Sector Clamps. This allows the string to wrap smoothly around the pulley without lying flat in between the clamps. The bridges are held in place naturally due to the sector geometry of the clamps, which prevents them from falling in or coming out. The pulley rotates around a 0.5in diameter rod and requires ball bearings to function properly, which can be purchased online. The bearing piece is held in the center of the pulley by a single plug via friction fit, with three tongues fitting into unused slots that are not occupied by the clamps. Ball bearings are secured tightly from the plug,