Cuboctahedron Rhombic Dodecahedron Compound pencil topper at approximately 21 mm X 21 mm X 21mm and I included a gradual decrease of size in the .stl design to hopefully make a snug universal fit. The cut hole in the Cuboctahedron Rhombic is at 3.30 mm radius and decreases to 2.90 mm. If you have a favorite pencil, you have to top it off with a cuboctahedron. Amaze your friends in class with a one of a kind pencil topper.
For simple conversion in inches (if you are unsure if it will fit atop your favorite pencil), 1 inch = 0.039 mm or for every inch, multiply it by 0.039. For example, at 3.30 mm is 3.30 * 0.039 = 0.12 inches at two decimal places.
In my pictures, I've aslo made different assortment of sizes to fit atop a pen, a papermate mechanical pencil and a BIC pencil. All have three different radius. I do not own rights to either manufacturer of pencils and do not claim to own. I am modifying my collection of writting tools that happen to have marketing rights. The .stl design posted on this page was originally attended to fit atop a wooden pencil, but as I've found some mechanical pencils will also work.
A Cuboctahedron Rhombic Dodecahedron Compouind is a convex polyhedron and has 24 edges, 12 vertices and 12 confruent rhombic faces.