[Author Prev][Author Next][Thread Prev][Thread Next][Author Index][Thread Index]
[ATM] RE: Glass for flats
I agree with Bob. In any case, trying your hand with plate glass flats is
OK. To cool the glass during polishing you can place the flat in a pan of
water. That seems to stabilize the plate glass in about 1 hour, instead of
the 24 hours it takes in air.
Don't get too ambitious at first. There are few things more difficult in
optics than a 1/20th flat. Producing one without pits or scratches requires
a true artist, lots of time, and tons of patience. Your are going to need a
monochromatic light viewer or sorts. There are plenty of models on line.
There is also a program on line called "three flats" that is useful in
testing.
If you don't have a master reference flat you will have to do the classic A
on B, B on C, and A on C. Use a sharpie test to see where you are grinding,
and a 0.0001" spherometer is also a nice tool to have. But this only works
as far as fine grinding. At polishing time you cannot do glass on glass. So
here is where the rubber hits the road.
I would start with three 4 inch flats, 6 inch at the most. Anything bigger
than that takes a true masochist.
Regards,
Julio
_______________________________________________
ATM mailing list http://www.atmlist.net/