On Thu, 13 Jan 2005 13:13:17 -0000, "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 is actually a Ham Radio application; I wish to make
up some very large banana-type plugs from the 1/4" round
bar stock that I have in small quantities. For this, I will need
to saw two diameters in a cross shape, and then splay
out the leaves slightly to make a springy and rubbing contact.

I usually use a 5C collet spin index, as
http://www.use-enco.com/CGI/INSRIT?PMAKA=235-6011
This makes it easy to get the two cuts 90 deg apart.

I set the height as Jim Rozen suggested. A hint there is to touch the
slitting saw as close as possible to the center, where it is supported
by the mandrel. That minimizes any flex in the saw when "touching" for
zero. I have a dial indicator mounted on the quill of my mill, so I
just lower the quill 1/2 dia + 1/2 saw thickness, lock it and cut.

Once you have the height set, it's easy to rotate 90 deg for the
other cut, then pop the piece out, reload another blank, and make the
next one. Shouldn't take 20 minutes to make 14 of them, once set up.
A set of holes and a tapered pin in the spin index makes it easy to
hit any increment of 1 degree with accuracy sufficient for most
purposes.

Those spin indexes are also handy for making hex heads or wrench flats
on round things, drilling cross holes at various angles, lots of
uses. One of the better $29.95 I ever spent!