Jon Elson fired this volley in
:

Well, if you check out the meat available, I think you'd
decide any serious boring will weaken the spindle too
much. I wouldn't do it unless you wanted to pass 3/4"
stock through the back. Generally, it needs justy a HAIR
more clearance.


Exactly, and you wouldn't lose too much stability/retention of a headstock
taper doing that. But boring it out larger would just compromise the whole
machine. It would be a destructive act, and wouldn't improve your
situation at all.

Lloyd