>the items that they have used. Olle had an excellent idea (IMO) for the >spider vanes for the diagonal mirror. He used hacksaw blades. Almost Just thought I'd mention that this is not my idea from the beginning but Nils Olof Carlin's. I've got a text written by him about spider vanes and their design on my homepage. The text is at http://hem1.passagen.se/astrosci/atm_diff.htm. Olle Eriksson