Going to take a class on telescope lens grinding, so Iv'e been reading up how...to get a head start. Relatively simple lapping process by hand. By lapping two mirrors together they naturally create an arc. When your done, you parabilize the lenz. So I was thinking, screw that, the glass blanks are halfass ground flat on the back. Say a 10 inch dia blank. So you use a vaccum chuck to hold it down, and cnc mill using whatever grinds the best the exact parabolic curve you want. Then, diamond polish it when done. machine it real fine using a spiral cut, making a few tenths stepover. Let it run for a few hours. Then some diamond polish. As opposed to 8 hours of hand roughing, followed by 3 hours of polishing just to get an inaccurate form.
So I'm trying to figure out what to cut it with. it polishes with aluminum oxide lapping dust so I know a regular grinding wheel will cut it, then there's borazon and diamond?
And why are people hand lapping them to shape, why isn't cnc being utilized?