Re: [ATM] A bit of hand polishing advice please................

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

G'day Jerry,

>The TDE was in all the images. It is not new after the last session of
work.

	Yep, I agree the tde is in all the images, just the amount seemed to
be increasing 


>Your edge is not awful. My recommendation on that is to spend a little time
seeing if you can learn to get it better, but don't let it stop you from
finishing you mirror in a reasonable time. Almost every mirror has some
degree of TDE. I say finish the first mirror and learn to make the perfect
edge on the second mirror.  Others will say that you should make it perfect
because you will have to live with it til you die.  I say you can live with
it and your second mirror til you die. If you do what others say you will
die with one unfinished mirror.  If you do what I say you will die with one
finished and one unfinished mirror.  You could discover a comet with that
mirror even if it has a TDE..... if it is in a telescope.

	This is the idea that we have. As long as each mirror is an
imrovement and you learn each time then to me and manuel there is no point
in slaving forever to get the last bit out of the mirror. In series 4
foucault you may be able to see at the 4:30 position halfway to the edge a
dark spot. The overarm on the machine grabbed and the arm stop didn't do
what it should have. The question was whether to grind the subsurface
fracture out or continue with the polish cursing occasionally! We chose to
perservere as we intend for the second mirror to be better. Of course it may
not be but we can only try............

	Series 4 of the pics again are after equalising overnight and again
after a couple of laps around the barrel, tot, 1/3 normal stroke. These have
just been uploaded.


Picures are at
http://users.cyberone.com.au/onslow/
Series 4 are the latest ones.


Cheers

John Murray
Whyalla
South Australia.

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