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Saw an article in this month's Sky and Telescope about the advantages of building your own scope, including grinding your own mirror. Must sound like lunacy when for peanuts these days you can buy a 6 inch reflector, mount and all, with a mirror correct to one-twentieth wave. Well for one thing it will teach you patience. Built my first scope when I was 13 because I had to. My parents couldn't fork out serious money on such luxuries as telescopes, especially for starry-eyed kids barely into puberty.
Even the cost of parts was a serious challenge. Luckily my dad worked with a company that used 8 inch diameter glass blanks for some obscure purpose. They made perfect mirror and tool blanks, and being made of pyrex was an added bonus. With a few dollars of grinding compound I was soon walking around a old barrel in the basement of our house in Toronto, happy as Larry.
Trouble was I was young and impatient. Couldn't wait for first light. Using strokes far longer than I should have, I had an f8 curve hollowed out in a few weeks. After polishing I discovered I'd created the finest hyperbola since Hubble. (I mean before Hubble.) No problem. The book said just turn the mirror and blank upside down and polish away until you get a sphere.
I did, but again being impatient used those long strokes to speed things up. Result? A lovely sphere with the biggest turned-down edge in the history of mirror grinding. It would taken 3 months to get rid of that, so I just ignored it, parabolized the mirror and then covered the edge with a piece of cardboard. My 8 inch suddenly became a 7 inch.
The mount was another problem, especially the tube. A local chap who made galvanised guttering was persuaded to whip up a very large 9 inch down spout about 5 feet long. The rest came from junk around the house, Being at 44 degrees latitude in Toronto was handy. A standard 45 degree cast iron plumbers elbow gave me an instant equatorial. And never mind that extra degree because I wasn't about to take 5 hour photos.
Anyway with help from Dad here and there it was finally done, and I must say there's few things in life more thrilling that seeing first light (the moon of course) through a scope made entirely with one's own sweat and tears.
And I learned that in this hobby you've got to be patient.
End of rant from old guy.
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