Ring Sector Model with Tray

When I teach cylindrical coordinates, I often refer to the shape labeled here as "Ring Sector." It is formed by creating a sector of a cylinder and then removing a sector with the same angle, but a smaller radius. Another teacher in my department wanted something similar for demonstrations in lessons for surface area and volume. We came up with the idea to have the outer ring along with the sector piece. I added the inner circle and sector for a nice puzzle-like model that illustrates it all and could be used for more shapes and activities. The tray holds it together well. We call it "The Cake."

I printed this with rainbow filament so that the top and bottom would be different colors allowing for an option during demonstrations to highlight various pieces by flipping them. It had the added effect of fun rainbow coloring on all of the inside edges. Different top and bottom colors could be also created with a filament change.

I printed all of the pieces together so they would have the same coloring with the rainbow filament. They have a 0.3 mm tolerance between the pieces and I needed a tool to help pull them apart. Keep in mind that making the pieces smaller would reduce this tolerance. Certainly the pieces could be printed separately so that is not an issue.

Also see my Volume Elements.

Whole model has diameter 160 mm and height 40 mm. The tray has diameter 167 mm and height 10 mm. I printed the model with 0.3 mm layer height and the tray with 0.2 mm layer height. The angle of the sector is 60 degrees.

Model printed with Stronghero3D "Exquisite" Rainbow PLA. I used 5% infill, 4 top layers, 4 bottom layers, and 3 outline/perimeter shells.