3D printing a large hollow sphere

[@nikosar100]

0:44 what is the “magic” angle of 116.6 degrees of the tool?

[@nikos44317]

If we look in Wikipedia at the entry Regular Dodecahedron, we see that the dihedral angle of a regular dodecahedron is 2 arctan(ϕ) or approximately 116.565° (where ϕ = (1 +sqrt (5)) / 2, the golden ratio). Nikos

[@evwbb]

Supercool we can make integration spheres at home considering they cost so much. Two questions, did you just use white paint for the diffuse and what are you gonna be measuring?

[@nikos44317]

Hello Hunter Beissert I am still experimenting with the coating of the sphere. Currently I am using an artist’s acrylic white based on Titanium Dioxide (PW6). The brand is Lukas. It is not as opaque as Talens but it gives a matte finish. Several thin layers are required to fully cover the black PLA. I will be using the sphere for recording transmission and reflection spectra. One port will host a spectrophotometer (a project in progress…). Have a very nice day. Nikos