Re: ATM mirrors

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

First off, don't bother making a spherometer unless you really want to for
measuring the regularity of the curvature of your mirror.  Spherometers
really won't show much unless you have a really good measuring device on one
at the finer grits.
As to stroke timing, in grinding you can go about as fast as you want to go.
I tend to get into a rythym with my muscles pushing my hands back and forth
with the mirror which produces a speed of a stroke out and back of about 1
second or so.  You don't have to worry about the speed of your stroke until
you are ready to figure the surface after polishing.
Make sure that you get those pits eliminated but don't keep chasing more
pits that happen as large pits are continually being generated as you grind
at that stage.  The large pits are created by the occasional super crackage
of the glass and you pretty much need to find the set from the previous grit
and eliminate those before going to the next finer grit.
Bob May
http://nav.to/bobmay
bobmay@nethere.com
NEW! http://bobmay.astronomy.net