riving knife on 500?

fitzhugh · Post by **fitzhugh** » Mon Nov 24, 2014 2:25 am

Admission: I've never used a table saw with a riving knife. I believe I understand the concept... Like a splitter, only close to the blade and stays that way as you adjust the depth of the cut. Am I missing anything?

I've got a 500 so all I have is the guard with the splitter. However, I don't mind setup time and an nervous already about the saw, so is there a reason I can't make a riving knife that mounts on the underside of the table and is manually adjusted for both depth if cut and horizontal/quill in vs quill out a bit? Or even angled cuts?
I know it would make little sense but if I had a bunch of the same cuts it seems worth it. I have to adjust the horizontal with the stock guard already.

I do recognize the hassle factor and if course an upgrade would solve it correctly, but that will be a long time most likely. It sounds like there is a significant improvement in safety with a riving knife over a splitter.

I guess including kickback prevention cams would be somewhat difficult. Why not just use the hypothetical riving knife to fill in the gap with the stock splitter?
Again, yet more hassle but I'm curious about feasibility.

JPG · Post by **JPG** » Mon Nov 24, 2014 8:37 am

If you already have a splitter, I do not understand what adding a riving knife would accomplish. The riving knife comes into play when the guard is removed for non-through cuts. Granted it would be closer to the blade.

dusty · Post by **dusty** » Mon Nov 24, 2014 10:53 am

JPG wrote:If you already have a splitter, I do not understand what adding a riving knife would accomplish. The riving knife comes into play when the guard is removed for non-through cuts. Granted it would be closer to the blade.

Riving knife and splitter has been terminology that I, for a long time, was just that - different words for the same thing but that is not true.

While they both can sometimes do the same thing, they do not always function equally.

The splitter is typically set 2 pr 3 inches (or more) back from the blade. It is nit uncommon for the work piece kerf to close down before reaching the splitter.

The riving knife, on the other hand, is mounted very close behind the blade and thus not allowing for the kerf to close down.

It is my opinion that the riving knife does a much better job of what it is there for than does the splitter.

Mounting a riving knife on the 500 might be a significant engineering feat. I don't know since I don't have a 500 to play with.

If I had the task, I would probably start by making it (the riving knife) part of my saw insert. This would make it much like a splitter but would allow it to be positioned close to the blade.

Gene Howe · Post by **Gene Howe** » Mon Nov 24, 2014 1:11 pm

I bought the splitters from the Grippper folks and have yet to install one. The set includes both full kerf and thin kerf splitters. Since I make my own inserts with a sacrificial piece for the saw kerf, setting that splitter closer to the blade wouldn't pose a problem.

edflorence · Post by **edflorence** » Mon Nov 24, 2014 7:55 pm

dusty wrote:R It is not uncommon for the work piece kerf to close down before reaching the splitter.

The riving knife, on the other hand, is mounted very close behind the blade and thus not allowing for the kerf to close down.

It is my opinion that the riving knife does a much better job of what it is there for than does the splitter.

Dusty...I completely agree with your conclusion that a riving knife positioned closer to the blade will be more effective than the splitter positioned further behind the blade. The comment I would like to toss into the mix, though, is that the space between the back of the blade and the splitter on my 500 is pretty short and even though I have experienced what you describe, that is the kerf sometimes getting narrower immediately behind the blade, I have never experienced a kick back from that. What has happened is that in the worst case I have to shut off the saw and move the splitter a hair to realign it with the kerf. So while the riving knife probably would work somewhat better, the splitter still seems to work pretty darn well. Well enough that, for me anyway, I don't see what is to be gained by spending a lot of effort on an after-market riving knife arrangement. I do like your idea of adding a splitter to a zero clearance insert as a way of getting the splitter closer to the blade.

fitzhugh · Post by **fitzhugh** » Wed Nov 26, 2014 1:22 am

Thanks guys,
I'm going on the emphasis placed on riving knives being better than splitters I've seen on various forums and in articles, but as far as I could tell the only difference is as you said - it is really close and stays that way when you move the blade up and down. Oh, and those lead to another benefit: people don't find them such a headache that nearly everyone takes them off and loses them, like splitters and guards. Since I'm a wimp around table saws I've always used the guard so I'm probably 75% there anyhow.

I was thinking of attaching it to the insert as said - would just have to adjust it when I made a cut. I'd have to think ahead more than normal since the dust collection shield is in the way, as I recall. Marking out on it where to set it for different heights (each 1/8 or 1/4 inch, say) would help.

What would probably improve my safety the most is to spend some time, like 15 minutes, reading up on safe use of table saws.

JPG · Post by **JPG** » Wed Nov 26, 2014 11:53 am

fitzhugh wrote:Thanks guys,
I'm going on the emphasis placed on riving knives being better than splitters I've seen on various forums and in articles, but as far as I could tell the only difference is as you said - it is really close and stays that way when you move the blade up and down. Oh, and those lead to another benefit: people don't find them such a headache that nearly everyone takes them off and loses them, like splitters and guards. Since I'm a wimp around table saws I've always used the guard so I'm probably 75% there anyhow.

I was thinking of attaching it to the insert as said - would just have to adjust it when I made a cut. I'd have to think ahead more than normal since the dust collection shield is in the way, as I recall. Marking out on it where to set it for different heights (each 1/8 or 1/4 inch, say) would help.

What would probably improve my safety the most is to spend some time, like 15 minutes, reading up on safe use of table saws.

Always!!!!!!

Wimp not, but fear is a good thing compared to complacency.

That leads to respect and better 'thinking'.

Just do not let it lead to paranoia.