Re: [ATM] Commercially available spherometer with Mitutoyo

["Greg Jones" <gregj888@comcast.net>]

Terin,

It's much easer than you think.  Metal plate works as does Plexiglas.  My larger one is out of Plexiglas... the small one is Al.  You can use a square piece of material if you want.  Mark the center and use a compass to scribe a circle.  Then either dimple where you want to glue the balls or drill and tap if you want to use screws.

I used sharpened brass screws on the larger unit.  dull the points a little and be careful (and I never use it on a polished surface).  Nylon screws also work.

The real key IMHO is to calibrate the spherometer against a known mirror.  If you just measure the mirror you'll also need a good flat, but a differential measurement between the tool and mirror works better for me. 

Hope that helps...


Greg Jones
http://home.comcast.net/~dac20/dac_001.htm
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