Moment of Inertia Project Update – By Olivia Danielson ’21

Post written by Olivia Danielson ’21

On April 3, 2018, Dr. Call presented a project for a couple of the 2021 fellows. He needed six 3D-printed models, comprised of five cylinders and one sphere, to demonstrate inertia for his Physics class. Inertia is the resistance of a body to change its momentum. What Dr. Call is going to demonstrate with our models is the moment of inertia, which is a measurement of how hard it is to change the shapes’ rotation rate. The way to measure that is by using this equation:

I = ∑m(i)r(i)2

The models were either solid or hollow. Solid meant that it had a 5%-25% infill, which could be changed when it came time for the shapes to be sliced. For a hollow circle, it needed an inner cylindrical hole that extended through the bases of the cylinder, creating a hole from the top to the bottom of the Cylinder.

 

We created all of these shapes using TinkerCAD, which is a “3D design and modeling tool” that one can use online. After we finish designing the models through TinkerCAD, we slice the shapes in Curia, which means getting the shapes ready to be printed. The printer that we use is 

a 3D printer called Ultimaker 3 Extended. Three out of the five cylinders and the sphere have the same radius of 5cm while the other cylinder has a 7cm radius. For all the cylinders except for one, the mass should be within 10g of each other. We aimed for around 103g. So far we have four cylinders done and one that is currently being printed. We plan to finish this project in early October.