Re: [ATM] Generated Tool does not Match Mirror Blank

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

Dave, don't worry.  The little flat spot won't make any
difference at all in the grinding as long as it isn't too big (a
half inch of flat spot on an 8" is fine)  Just start grinding and
you will find that it will probably quickly go away.
Inspect the surface of the glass for the grit size that should be
used for the first grinding.  I usually start pregenerated
mirrors with 320 grit on a tile tool and back up if there are any
problems wit holes in the mirror (the tool is pretty irrelevant
here unless the curve is different in the ROC).  Since the mirror
and tool were probably done on the same machine one right after
the other, the curvature is probably very close.
When you choose a grit size, do at least 10 wets with it if the
surfaces seem to be matching and then look at the mirror to see
how it is looking.  Then do another 10 wets to get rid of any
deep cracking from the diamond grinding operation.
Bob May
bobmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net
Addresses have been munged up to keep spammers from bothering me.
replace the obvious words with the proper character.
Thank you for your understanding!

_______________________________________________
ATM mailing list http://www.atmlist.net/