Morse tapers are great for drills, but an uneven load will work them loose
if the quill doesn't have provisions for a drawbar to insure the taper stays
locked in place.

A 3" radius cutting tool will be a significant side load depending upon how
it approaches the work.. especially for a #1 MT.

There might be a stub arbor in #1 MT that's as big as 7/8", but probably not
very common.. 7/8" would more likely be found on a #2 or 3 MT, maybe.
The #1 MT is for small accessories/tooling such as the small chuck you have.

--
WB
..........


"Tom Gardner" mars@tacks wrote in message
...
I have my high-speed spindle, a drill quill made to run 10k rpm. However,
it has a M-1 male taper that holds a 1/4" Jacobs chuck. I need to mount a
6" x 1/16" x 7/8" AH cut-off disk. Is there a commercial adapter or do I
have to make something?