Re: [ATM] Lens Wedge

[gregj888@comcast.net]

>From experience, you can control wedge to any level you can measure.  I used a fixture- 3 pins to hold the lens horizontally (at the edge should it produce a scratch).  2 pins to act as a stop laterally and a dial indicator.  I shot for 0.0002" (basically the width of the needle in the dial indicator) and think I hit it on the 8" lenses.

In the case of the Houghon, simply mark the thickest side of each lens and when they line up apply some extra pressure to that side.  The goal is to get the wedge to withing the variability of the grit you are working on then maintaini it.  Your 0.003 needs to come down below 0.001 during the hogging process and before you hit your desired radius.

You will be surprised how easy it is.   Here's what I started with:
  http://www.newportglass.com/share.htm

Greg Jones
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