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Old 28-04-2018, 07:43 PM
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Lognic04 (Logan)
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Join Date: Mar 2016
Location: Melbourne, VIC
Posts: 889
Quote:
Originally Posted by OzEclipse View Post
Hi Logan

To make a perfectly flat (optically flat) surface, you need three blanks and they have to be regularly flipped top to bottom and swapped in and out of the pair.

I am understanding that you mean you are grinding the back of the mirror flat? Unless it is really uneven, it's not necessary to flatten the back.

However if you want to do it, then yes, do flip the 2 mirrors otherwise the top one will become concave. Flipping two mirrors, will make them roughly flat which is all you need.

Cheers

Joe
Thanks Joe. It is mostly done now anyway, so soon I can go onto rough grinding! Hopefully I don't use all my 80 grit on this!
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