The file 'Grid-shadow Projector 3D Printer Model' is (stl) file type, size is 62.2KB.
Some time ago a friend of mine asked me to reproduce in Inventor a picture he saw on the Internet, representing a nice finding where someone got a cool squared pattern using the shadow projected by a spherical 3D model and a punctiform light such as a LED (https://www.theguardian.com/science/alexs-adventures-in-numberland/2014/oct/30/pumpkin-geometry-stunning-shadow-sculptures-that-illuminate-an-ancient-mathematical-technique). Here are the two models i drew, having almost the same virtual projection but different practical results (number 2 is a refined version of number 1).
One more thing: both the models need to be re-oriented before printing.
P.S. I've seen that there are other analogue models on Thingiverse. They are great works but, well... here's mine. I hope you will like it.
Omothetic_sphere_1.stl | 76.6KB | |
Omothetic_sphere_2.stl | 107.0KB |