Table saws with riving knives

[Noah Katz]

It's a mystery to me why more saws don't have riving knives, which if my understanding is correct, is simply a splitter that both raises and lowers and tilts with the blade.

Besides being curious as to what kind of carriage beef the SawStop gives you for all that $, I was curious whether there's anything unique that related to the incorporation of a riving knife, so I looked at the exploded view of the SawStop carriage assembly; p.81 in the manual

http://www.sawstop.com/Cabinet_Saw_Manual.pdf

There is indeed - rather than a simple pivot giving the arbor a circular trajectory, it's guided on two vertical shafts driven by a threaded rod.

This would keep the riving knife at the same relative height to the blade at any height setting.

The Powermatic PM2000 exploded view is on p.34 here

http://www.wmhtoolgroup.com/partfiles/m_1792001K.pdf

It's not exactly clear because the riving knife is shown on a different page with the guard assembly, but it looks conventional as far as I can tell.

Maybe there's more to it, because that would mean that it would suffer from what I think is the reason more saws don't have a riving knife, which would be the change in height of the knife relative to the blade mentioned above.

I'd be interested in anyone's knowledge/thoughts on this issue.

Thanks

[Rob Bodenschatz]

This was discussed here:

http://www.sawmillcreek.org/showthread.php?t=43661

Maybe you'll find something in there. Although I do have a PM2000, I have very little useful information to add other than I'm pretty sure my riving knife has saved me a few times from kickback.

[Noah Katz]

Rob,

Thanks for the link, I was remiss in not doing a search first.

[Mike Henderson]

This is a bit off topic, but I think I remember reading somewhere that all table saws sold in the US after some date will be required to have a riving knife. Does anyone know if that's true, and if so, what that date is?

Mike

[Larry Conely]

I guess this is pretty much useless information for today's world. Both my Inca 12" tilting arbor saw and 10" tilting table saw have arbors that travel up and down in a strailght line, not pivot. Twenty years ago this was one of their selling points that the riving knife would always be in the right orientation.

Larry

[lou sansone]

I have owned two American saws that had riving knives and loved them. they are the Oliver D and the Rockwell RT-40 ( ok it is made in Brazil but by an American company ) . The oliver does not pivot per se, but rides on a turret along with two five hp direct drive motors. The Rockwell pivots.

Lou