Quote:
Originally Posted by Rod
Hi Logan
Yes that's my old tool.
Assuming a sag of 2.1mm and a diameter of 250, your focal ratio is currently 7.4 according to the stellafane calculator:
https://stellafane.org/tm/atm/mirror...g2fl-calc.html
So there is a little more hogging to do, but I am impressed by how quickly you are getting to your target!
I am a little nervous that you may grind through those thin tiles at some point. I would feel better if we glued some new tiles over the top. At 80 grit new tiles will conform to the curve you are grinding very quickly. I could bring some epoxy (jb weld) and tiles to the meeting next Saturday if you would like to do that.
Happy grinding!
Rod |
Nice to know who used this tool before! I am at about 2.3mm now. I dont hink the tiles will actually get that thin, its at about 3mm thick still.
