Re: ATM Why a star lap?

["James W. Burrows" <burrjaw@earthlink.net>]

At 00:14 2002-01-02 -0500, Joseph Johnston wrote:

>      Would someone explain or direct me towards an URL that would explain 
> why, when and
>where a star pitch (or other material) lap is used. I vaguely understand 
>that it polishes
>differently then a full surface, channeled lap. It would seem to me to 
>have better control
>through a slower removal of glass. Correct?

A starlap  (star lap?) increases polishing action over surface areas that 
are high relative to a desired profile.  I've written a program that 
computes the shape of a starlap, given a file of surface deviations.  There 
are two shapes - they're different - a lap for stroking and one for use on 
a turntable.  Download:

         http://home.earthlink.net/~burrjaw/public/starlap.zip

         -- Jim Burrows
         --              mailto:burrjaw@earthlink.net
         --              http://home.earthlink.net/~burrjaw
         -- Seattle      N47.47233, W122.36620 (WGS84)