I'm attempting to build my first scope from the sidewalk astronomer plans (8" f/6), and have a few hopefully not too foolish questions.

The primary mirror mounting scheme in the plans looks iffy to me, the idea of relying on nailheads to keep the mirror from rolling out of the tube scares me. Woud it be OK to loosely inset the mirror into a pocket routed into a backing board and loosely hold it down with some small clips?

Where should the focal point of the system be? I understand that the diagonal sends it toward the focuser tube, but should the point be somewhere up in the focuser tube, or right where the focuser tube meets the main tube?

How accurate can I expect the advertised focal length of a purchased mirror set to be? I ordered it from Scopes-Online?

• answers for u rookie - stevec - March 29, 2001 - 09:02 UTC
• A Few Rookie Questions - bobmay - April 3, 2001 - 05:22 UTC