I learned a couple of books could help me pretty well, but i don't think i need to buy those books just to make the mirrorIt would be very nice if someone could just tell me the major steps in the fabrication of a parabolic mirror, just to get me startedLike how to make the basic parabolic shape, what material to use for the reflexion(aluminum?), how to polish it, tips, etc, and i think i could fend with the rest.Thank you very much!
First make it spheroidal, then figure it into a paraboloidSome books [e.gTexereau's (in French) and Allyn Thompson's] are onlineThe links are at telescope makers' Yahoo! webgroupsYou make the mirror out of a plate glass disk or Pyrex glass diskA first project is usually in the 4 to 10 rangeYou first grind out the concavity with coarse grit and another glass diskA spheroidal shape occurs naturally as one disk becoming concave and the other convexThen you smooth the concave surface with progressively finer abrasive gritThen you polish the surface with cerium oxide or jewelers' rougeThen you optically test the surfaceThen you use appropriate polishing strokes-selectively removing glass to change the the shape into a paraboloidThen you clean it and have it aluminised in a vacuum chamberFor someone with experience who is all set up a 4 mirror can be ground, smoothed, polished, figured, and aluminised in a dayAs a first project it would take a few weekendsThere are 20+ telescope making groups/classes/workshopsSome are listed at the Stellafane websiteThe suppliers of glass and grit in the US are GotGrit, Willmann-Bell, and Newport Glass WorksA 4 mirror starter kit (with two disks, the abrasive, the polish, and the pitch) is about $80NGW and GG show some prices at their websitesWB will email the telescope-making supplies section of its catalogThere are telescope-making Yahoo! webgroups, like atm_free and make_your_own_telescopeThey list weblinks to a few online booksAnd a telescope making webringAnd a good forum-the ATM Mailing List.
