Re: [ATM] overshot sagitta correction stroke

["Bob May" <bobmay@nethere.com>]

Jerry, the curvature will eventually approach a value (fairly short ROC)
where it will remain stable but for the most part, the basic physics of
grinding where the higher the pressure between the two surfaces, the more
the wear on the surfaces. will insure that the ROC will always keep on
shrinking.  The shorter strokes tend to keep the wear even as the weight on
the local surface won't change much as the stroke happens.
The thing that is nice about smaller spherometers is that you can measure
parts of the surface and find out if the curvature is equal over the whole
mirror surface.  You run into the problem tho of the spherometer size, which
determines the accuracy, and how accurately you can measure the surface
curvature.
Bob May
http://nav.to/bobmay
bobmay@nethere.com
NEW! http://bobmay.astronomy.net


_______________________________________________
ATM mailing list http://www.atmlist.net/