Now, that's interesting, because it is a variation of the technique
for setting up for cross drilling (except that then the ruler is in
see-saw mode)

"Wooding" wrote in message
...
Airy R.Bean wrote:
Is there a "kink" for setting up a slitting saw to saw through
round bar stock along the axis, so that the slot is exactly
across a diameter? (I presume this to be a similar problem to
setting up accurately for cross-drilling)

This trick assumes you have the slitting saw in a vertical mill, the bar
is horizontal, and the slitting saw teeth are straight (i.e.. not
staggered like a wood saw blade).
Adjust the position of the bar and saw so that, by eye, the blade is
just about touching the fattest part of the bar. Interpose a vertical
6" steel rule between the bar and the saw and move the table to very
gently pinch the rule. Unless you were lucky and set the saw exactly on
the fattest part, the rule will no longer be vertical. Adjust the hight
of the saw until the rule is truly vertical - you will be amazed at how
accurately the blade is then at centre hight.