Re: [ATM] An update on our mirror.........

["John and Bernadine Murray" <onslow@cyberone.com.au>]

G'day Dale,
	From the 3rd series of pictures on, all of the work was by hand. All
of it since has been 1/3rd coc with tot. A touch of tde has crept in from
early on so in the 6th series I have also gone for a slightly shorter 1/4
coc tot stroke. That's the series 6 pictures. I have just completed the
seventh session and will post pictures in the morning when it's acclimatised
over night. 24 hrs for that I'm afraid. I've been doing the last three
sessions after coming off 12 hr n/shifts so in the warm weather it takes a
bit longer to get the thing acclimatised.. I'm doing around 2 -3 seconds for
the strokes. The early foucault surfaces were lumpy but that is slowly
coming under control now. The good news is that this isn't my mirror ;-) and
a mate and I are doing it for the learning curve more than the end result.
The thing has a sub surface fracture from when the arm on the machine used
the glass to stop. The bloody arm stop didn't work to well
unfortunately!!!!!!!!! It's visible in some of the pictures. We decided to
continue on and see how we go. I know some people say make the best you can
to start with but the thing needs regrinding to get the ding out. In the end
Manuel decided lets just learn and then revisit it later. We've got a few
projects we want to do so the experience is more important than this
particular piece of glass..................


Cheers

John

-----Original Message-----
From: atm-bounces@atmlist.net [mailto:atm-bounces@atmlist.net] On Behalf Of
Dale Eason
Sent: Sunday, 26 November 2006 8:29 AM
To: atm@atmlist.net
Subject: Re: [ATM] An update on our mirror.........

John,

Next you need to try for smoothness.  I can see several concentric ellipse
like rings.  If you are trying for the best then you need to smooth those
out as well.

I don't know about machine work but for hand work I found you need to move
the lap very slowly about 1 to
2 seconds per stroke to get a smooth surface.

Dale Eason


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