Clamps Clamping the rocker box of a 20″ Obsession Related Posts John Dobson (1915-2014) Rebuilding a 12.5" f/5 Truss Tube Dobsonian Share this:TweetWhatsAppEmail Author: Andrew An electrical engineer, amateur astronomer, and diver, living and working on the island of HawaiĘ»i. View all posts by Andrew