How
I built the 12 inch scope
End
of 60 grit cut
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This is what the glass appears as at the end of the 60 grit stage. My target depth is 3.81mm to achieve f5. I stopped grinding the 60 grit at 2.91mm as the next 120, 240, 400 & 600 will still cut deeper. The bottoms of the pits from 60 girt are probably around 3.5mm'ish. |
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I am using automotive feeler gauges to accurately measure the depth. No tricks so far. |
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