RE: ATM Parabolising - different methods - merits

["Bertapelle, Ken" <Bertapelle.Ken@tci.com>]

Can someone give a description of this "starfishing the lap" process?
I'm imagining a situation where one draws a starfish outline on the
lap, and then scrapes those pitch squares which are outside the 
outline.  Is this correct?  How much do you scrape?  Is there a 
noticeable difference in the height of the lap inside and outside the
outline?  Thanks.

- KenB

-----Original Message-----
From: Mel Bartels [mailto:mbartels@efn.org]
Sent: Friday, June 18, 1999 9:46 AM
To: Hugh J. Masterson
Cc: atm@shore.net
Subject: Re: ATM Parabolising - different methods - merits

 Star lap is merely a method to
concentrate more pitch in a tigher area thus allowing a steeper or
deeper bowl to the center of the mirror when the large fast mirror calls
for more parabolization.  In other words, the star lap resists the
return to spherical mirror easier.  We call it 'scalloping or scouring'
the sides of the parabolization.

--
Clear skies, Mel Bartels
http://www.efn.org/~mbartels