Making parabolic mirrors is hard. Spinning mirrors out of epoxy has been long researched and abandoned. However I’m stubborn so I attempted it regardless. The results were surprisingly high quality for the worst possible manufacturing contexts: pottery wheel, no degassing, not covered or in vacuum, random un-tuned epoxy. Below is a program I wrote to help calculate the materials and rpm necessary to achieve the desired focal length and diameter. I never ended up aluminizing or silvering this version so it simply exists as a proof of concept however I hope to pursue this project in the future.
https://colab.research.google.com/drive/1y_oXxvRIDy8eLIckfEyfvZn7B5mR0HMu