Question on Woodsmith Shop's DIY ZCI plates

[Lewis Cobb]

Hi -
I was looking over the Woodsmith Shop's website and came across a design for a DIY ZCI plate. They basically used a piece of 1/2 BB ply and cut a slot in it, then glued in a little wood splitter at the back - which also provided the stiffener needed for the plate.

They are using a PM2000 tablesaw, it looks like they took off the riving knife and don't even consider it with this ZCI (the splitter providing the safety function).

This seems a little wrong to me for some reason - not sure why - it's just that the riving knife is designed to rise and fall with the blade and stay just underneath the top of it (the low profile one that is). But then again, for most work 3/4" and below, the splitter does the same function as the riving knife at 90 degrees.

Anyone else that has this nagging feeling that a ZCI should still use the saw's riving knife ?

Lewis

[Mike Nolan]

My home built ZCIs for a PM 2000 includes a slot for the riving knife. I think that one of the main advantages of a riving knife is that I don't need to take it off.
A splitter is OK but for me (lazy) it is not as good.

Mike

[Bruce Wrenn]

To use riving knife, blade slot has to be longer than what the blade will cut without repositioning the ZCI. I have a jig for that, but can't share it right now.

[Chip Lindley]

If it's a big issue with you, should be easy enough to cut a slot in the ZCI to expose the riving knife on the saw. Since none of my TSs have included riving knives, I can't say it bothers me.