Bandido is right, it can work. The problem is that the right combination of feeds and speeds that will give that finish without chatter and without having to "tend" the shaft while turning will most likely be slow. I need to be able to turn more peices. For the OB-1 shaft, my first turning on the .625" squares makes 4 passes at 40 inches per minute, and it takes me a little over 2 1/2 hours to turn 156 peices on Blud's 4 saw CNC machine.
My concern for Mike is that he has to "tend" the shaft while it cuts in the middle. If that is the case Mike, you do not have something right in your setup. From my experience, I was not able to get satisfactory cuts and speed from the slitting saw. With 3 wing slot cutters like these on my router
http://www.mytoolstore.com/everlast/evr22.html
I get smooth cuts, plenty of material removal when I need it, and the ability to go a little faster. And all of this with no "tending". And the bits are only $8.72 each. Plus, these are carbide, not high speed steel, and last much longer.
Royce Bunnell
www.obcues.com