ATM trepan I

[Ina Ron Lippard Renaissance Reproductions <renrepro@surfglobal.net>]

    After making the first hole-saw I put my set-up through its paces. 
Before starting I put
the tool in the mill and placed 1/4" notches in 8 places around the rim. 
This would tend to
trap some grit in the cut and also serve as a gage to check the amount of wear.
   I took my time cutting through the 1/2" plate glass Nate gave me to cut. 
The actual drill time was 45 min. I used #90 sil/carbide. I found that if 
you 'ride the grit' a bit,your cutting action
is much more efficient then putting too much pressure on. This is easy to 
detect as you
here a squeal when steel meets glass. When complete,I not only had a 
perfect 4 1/16" blank
but a nice square of plate with a 4 3/8" hole in the middle.A #80 stone 
dunked into water
did a nice job of taking off the slight break-thru on the back side. No 
clamshells to speak of.
   The junkyard I now frequent has some re-saw blades. These are band saw 
blades used in
planking out larges pieces of wood.They are about 6" wide and 3/32" thick. 
They will
make excellent hole saw blades since they already have gullets in them and 
are harder
then a mother-in-laws stare when you get caught!
    As for the tile thread,I would suggest anyone with the yen for 
knowledge should just go
to a local tile store and ask some questions. While you are there, take 
note of their
diamond products and tool inventory.You WILL gain some insight.
regards, Ron
BTW,the wear on the hole-saw was not detectable.