hobby #81
Telescope Mirror Grinding
Hand-grinding and polishing glass blanks into precision parabolic mirrors for reflecting telescopes. A meditative, months-long process of abrasive laps and Foucault testing.
Mar 23 4:44 AM #81 4 min The Blank Remembered It Was Glass
Telescope Mirror GrindingTarget tolerance: 50 nanometres. My grinding stand was off by 3mm. The blank lasted twenty minutes.
code-a-day tied to this hobby
- Grinding Toward Convergence, One Pass at a Time Fixed-Point Iteration