“rubbing generating two perfect planes.”
The model is constituted of an abrasive disk that turns upon a transmission shaft, actuated by a crank. On the same shaft, a system of crank and connecting rod is mounted, connected to a secondary shaft and to a toothed wheel positioned inside a circular crown, also toothed.The crank is turned to produce two movements: the rotation of the abrasive disk and the simultaneous movement of the mirror mounted on the toothed wheel that moves in epicycloidal manner (turning about itself and along the toothed crown), causing the mirror to be uniformly abraded by the polishing disk.
The model is based on the drawing:
- Codex Atlanticus f. 1103 v. (1513-1515)
Milano, Biblioteca Ambrosiana