Re: [ATM] Schmidt corrector grinding tool

["Bob May" <bobmay@nethere.com>]

The tool for the corrector should be ground to the correct radius before
starting the corrector.  A tile tool really will make things slower if you
have to grind against the corrector so don't bother.
Remember that the amount of glass needed to be removed is very minimal and
oftimes, just polishing will bring out the correct shape.  I tried a 6"
F1.95 (failed because the glass at 0.170" thick broke both times due to
stress) and am going to be trying again with thinner glass when I get the
time.  The glass was ground flat by the  disc method and then was stressed
in the vacuum pan and polished out from the 5 micron point.  Polishing speed
was a little slower as the ring needed more work than the center and edges
but it polished out in a decent amount of time.
Bob May
http://nav.to/bobmay
bobmay@nethere.com
NEW! http://bobmay.astronomy.net


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