Re: ATM Aluminum, Split Ring, Astrograph

[Donald Clement <clement@inetworld.net>]

Bruce Sayre wrote:
> Alternatively, there may be a commercial milling machine out there somewhere big enough 
>to
> do the job. It will be precise and the only way to go if money is no object. As in many
> endeavors, you usually get what you pay for.
> 

I have seen large discs turned with a small Benchmaster mill. The discs
were mounted on a faceplatewith the mill configured as a horizontal .
The disc was spun. A lathe tool was mounted on the table and the disc
turned as if in a lathe. The late Bill Shaefer used this method. The
same method is explained by William Browne in "Turning Large Diameter
Work"  from "Advanced Telescope Making Techniques , volume 2" by Allan
Mackintosh.

Don Clement
San Diego/Running Springs