riving knife??

Chris Mire

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Southern Louisiana
i have been hearing alot about riving knives in table saws lately. i am not sure i know what they do and why they makes the saw safer. can anyone explain that for me. if i remember correctly i think they help to fight against kickback??

thanks
chris
 
Chris, the riving knife or a splitter (they are two different tools that do a similar job) prevents wood that has stresses in it froom closing up behind the blade. Without a RK or splitter, the wood could close up, pinch the blade at the back, the blade picks up the wood and throws it back right at where you are standing, whacking you in the face (or other parts of your body).

That about sums it up I think.
 
Let me add that the ones I have seen also come up over the top of the blades. The raise and lower with the blade. That keeps the wood from coming to rest on top of the blade that is spinning toward you. That where the kickback happens, the wood getting on top of the blade, teeth grab the wood and rocket it toward you.

From what I understand it's a great thing. In theory anyway.
 
Let me add that the ones I have seen also come up over the top of the blades. The raise and lower with the blade. That keeps the wood from coming to rest on top of the blade that is spinning toward you. That where the kickback happens, the wood getting on top of the blade, teeth grab the wood and rocket it toward you.

From what I understand it's a great thing. In theory anyway.
That's exactly it, they rise and lower in tandem with the blade. So, they can be used with non through cuts and with angled cuts.

They are a great thing in practice as well as in theory. :) I have one on my circular saw (Festool) and really wish that I had one on table saw.

One other thing, I understand that they can not be retro-fitted to the traditional North American style table saw. :( If they could be, I would right at the top of the queue to purchase such a retro-fit. I have seen a couple of claims that they can be, but no proof.
 
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thanks guys...that is basically what i thought. but i wasn't sure if there was more to it than that.

frank...i'm a little confused...how can it be used on non-thru cuts??
wouldn't the non cut section hit the RK and stop the board? :dunno:

chris
 
thanks guys...that is basically what i thought. but i wasn't sure if there was more to it than that.

frank...i'm a little confused...how can it be used on non-thru cuts??
wouldn't the non cut section hit the RK and stop the board? :dunno:

chris
Chris, the riving knife is set to be even with the top of the blade, and it travels up and down with the blade (and sideways for bevel cuts). Since it is no higher than the blade itself, a non-through cut can still clear the knife.

HTH -
 
One other thing, I understand that they can not be retro-fitted to the traditional North American style table saw.

From what I have seen your right. I gave my Delta contractors saw I sold and my old Unisaw a good looking over and there is no easy way I can see to attach a riving knife to either of them. The problem is that there is no where ton the arbor bracket to attach one so it can raise and tilt with the blade.
 
And here is a few photos of a plain old splitter.

First, this is the home-made splitter that I made for my General International 50-185 tablesaw. It is just a piece cut from an old shelf standard. Just a flat piece of metal with a notch out of it to fit around the bolt.
splitter1-sm.jpgsplitter3-sm.jpg

I like a splitter like this a lot, as it lets me use a crosscut sled without removing it.

Next, here is some pictures of the microjig splitter from the Lee Valley website. This is another aftermarket splitter kit that you can get, which will fit just about any tablesaw.
03j8020s2(2).jpg03j8020s5.jpg

Finally, if you visit www.leestyron.com you can see photos, videos, and other information about the shark guard. I don't have one, but it has been very well spoken of by people on various WW forums. (it incorporates both a splitter and guard, for many brands of saw.)

...art

ps: and yes, if I was in the market, I'd want to look seriously at a saw with a true riving knife. The splitter is good, the riving knife is better, IMHO.
 
I had a nasty kick back last year. 95% of the time I use a sled so taking the stock guard and splitter off and on was a real hassle so I quit bothering with it. No real damage, but the board hit me in the abdomen right below the sternum and knocked the wind out of me. Had a nice bruise for awile, too. Within a few days of the incident I bought an Excaliber splitter (quick release) and installed it. Now when I'm not using my sled, I snap the Excaliber into place and go. I don't want a repeat that could possibly have a worse result.

That's the problem with many of us. We have to learn the hard way.;)
 
Todd, granted riving knives are fairly new thing to me, but the one I saw came futher over the top of the blade. That looks more like a splitter to me or would funtion more like a splitter. The one I saw would prevent the wood from ever getting on top of the saw blade and doesn't look like that one would.

So what you have the norm for riving knives?

Jeff
Kind of confussed here
 
jeff, this is my first saw with a riving knife.....the other scmi saws i`ve seen use the same design and the older altendorf i drove had one that looked very similar but it layed in the tool box and was never installed....best of my recolection from iwf the martin and altendorfs both stopped short of covering the top.........but i`m relying on my one functional cell for memory here:eek: tod
 
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Next, here is some pictures of the microjig splitter from the Lee Valley website. This is another aftermarket splitter kit that you can get, which will fit just about any tablesaw.
View attachment 2203View attachment 2204
...
I do use this on my table saw (a General 650). It's not a riving knife but, in my opinion, it is better than the standard splitter that came with the saw.
 
Could someone please explain the difference between a splitter and a riving knife ? I've used the terms interchangeably for years. They both serve to keep the kerf behind the blade from pinching the blade, jamming the saw or hurling the piece of wood back in your face, don't they?

Just curious.
 
Could someone please explain the difference between a splitter and a riving knife ? I've used the terms interchangeably for years. They both serve to keep the kerf behind the blade from pinching the blade, jamming the saw or hurling the piece of wood back in your face, don't they?

Just curious.
The difference is that a riving knife rises and lowers and turns in conjuction with the saw blade. A true riving knife is never higher than the saw blade so can be used on partial cuts.
 
thanks everyone. that really clears it up for me. it really seems a riving knife would be a great addition to any table saw. now to find a way to retrofit them...:huh:

chris
 
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