Replies

1. 
   JohnWW | Dec 02, 2008 04:44pm | #1

   Zolton,

   Well it seems to work, and as long as you are willing to make some small adjustments in the knife's position to get the best protection at different blade heights it should make the saw safer to use.

   One problem that I see is that the bar that supports the knife is relatively weak and its attachment to the arbor assembly may not be rock solid. If the knife could shift out of position it would make the saw less safe, just the opposite of what you are trying to achieve. I also suspect that the bar's position above the arbor limits the height that you can raise the blade to, leading to some loss of cutting depth.

   John White

1. 
   zolton | Dec 02, 2008 05:53pm | #2

   John,

    I was concerned too about the stability of the retrofit riving knife arm. It looks as though it is fabricated of a steel shelving bracket standard that is available at big box home centers. Kind of a clever use of the material, if that's what it is. But it is low grade steel and not really designed for this application.

   In looking at the photos and examining my own saw, and thinking about this, I think the riving knife would indeed rise and fall when the blade is cranked up and down. It appears as though the knife is only attached to the arm and not the trunnion in the rear of the saw, where the OEM splitter is designed to bolt on.  So, because the arm is affixed to the arbor assembly, as that assembly rises and falls (well, rotates through an arc) the riving knife blade would as well.

   I think the knob adjustment you see in back is simply to enable the user to adjust the knife height for either through or non-through cuts on the material. If the idea was simply to make a riving knife that would need adjustment for every depth of cut, there would be no need of the arm that's attached to the arbor assembly. You could use the original mounting point for the splitter and a knife shaped like a shark's fin.

   But, again, I'm a bit leery of the idea of something attached with a hose clamp so near the blade. A lot of stuff could start flying around should things shift or break.

   Still, it is a clever idea, and with the right materials it looks as though it's something that could be made to work - and to supply a retrofit riving knife to a saw that didn't originally have one.

   Thanks for your insight..

   Zolton 

    If you see a possum running around in here, kill it. It's not a pet. - Jackie Moon