ATM: Cutting Glass Circles

["Richard Andersen" <RichardA@island.net>]

I may be sticking my $.02 in incorrectly as my experience is from 
'way back' but in my old ATM days we made circular glass cuts with a 
a drill press and a slurry of about #80 Carborundum. We had circles 
of wood with a concentric center shaft that could be chucked in the 
drill press. A length of sheet metal was securely fastened around the 
rim of the disk so that it formed a large diameter short tube, just 
long enough to pass through glass to be cut. The glass was mounted on 
the drill press table, a ring of putty formed a dam just outside the 
diameter of the cutter, and the space filled with abrasive and water. 
The drill press, run on its lowest speed, was started and the feed 
weighted. It took quite a while to cut through thick glass but only 
occasional attention was required. It was a variety of mud saw, 
similar to those used in the stone cutting industry.

We cut everything from large disks for tools (12" was the biggest I 
remember) down to quite small stuff; once I cut a 1/2' diameter 
section out of an electric welders faceplate glass to make a solar 
viewing filter.I used a section of brass tube for the cutter in that 
job.

 
Richard Andersen
Victoria, B.C., Canada