Re: [ATM] ATM - Zerodur- how much harder to figure?

[Bernard Maugoust <maugoust@free.fr>]

In message <20040726142023.36152.qmail@web40608.mail.yahoo.com>, 
 Ric Rokosz <radicell2@yahoo.com> wrote:

>  I was wondering how much longer it takes to
> work/figure a piece of Zerodur compared to
> pyrex,especially the figuring part considering that
> Zerodur is rather harder than pyrex.Was planning to
> use Cerium Oxide..is it really a lot ,lot longer or
> just a tad bit longer?

My 2 cents:

>From my own experience, expect everything to be longer by a factor of 2 to 3.

My 8" F/5.26 took about 48h to grind, 25h to polish with rouge and some 20h
to figure (mostly with zirconium). All by hand.

The one up side of Zerodur is that Foucault readings can be taken right after
each figuring session ;-)

Before that I'd done my hand on plate glass as per Texereau, and I recall I
was rather OK as far as his timings for doing things are.

Have fun...

-- 
Bernard Maugoust 3°59'E 44°28'N

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