Building your own telescope is not always about saving money. It is about gaining knowledge and skills and pushing reflexion further. The build usually consists of 2 parts: building the structure and building the mirror. While the first one took me around month, the second one was definitely the most time consuming. Some people prefer to do the wood and metal work and order a finished mirror. However, i think this step is possibly the most interresting part of the construction.

To build your own mirror, you will need:

  • a glass blank (pyrex, zerodur, duran 50, etc) of the required diameter and width.
  • a tool either in cheaper glass or water resistant plaster (ex: Staturoc) covered in ceramic tiles.
  • abrasives from coarse (carborundum) to powder (cerium oxide)

The main steps to give your glass blank a circular shape are:

  • grinding (give an approximate curvature)
  • reuniting the spheres of both the tool and the glass
  • smoothing
  • polishing
  • parabolising

Once the mirror has been parabolised using the Foucault knife-edge test, it is carefully cleaned and sent for aluminisation in a vacuum chamber.

  • Project: Parabolic Mirror
  • Technology: Glass grinding and polishing
  • Material: Pyrex Glass, Staturoc plaster, tar
  • Time: 1 to several months