Thread: Carbatec 10" cabinet table saw: Low profile riving knife

I don't use a riving knife or splitter when cutting grooves. They're normally used to prevent the timber closing in on the blade when cutting all the way through.

Thanks for the reply Lappa.

I'm not really sure why any table saw would design the riving knife to be above the height of the blade. Because even when your cutting timber all the way through, the only part of the knife that is actually provided support (and preventing kickback), is the material directly behind the blade and below the top of the blade. All that material of the knife above the height of the blade, to me, isn't doing anything, even when cutting timber all the way through (because no timber will ever pass beside it.).

Not sure if I've explained that well. But you hopefully it you get a better idea of what I'm trying to say.


I'm still a little nervous about removing the knife even when cutting groves, as the kickback potential is still there as demonstrated by the video below.
https://www.youtube.com/watch?v=u7sRrC2Jpp4

You could always purchase a replacement knife and modify it to suit.

Some table saws have the rise/fall on a pivot, which means that the knife is substantially higher than the blade at max height but not when it's only projecting a bit above the table, other saws have a linear rise/fall so the knife is the same position relative to the blade regardless. The type of saw you have will determine the safety of cutting it down.

If it's linear, cut the knife off about 2mm below the top of the blade. If it's on a pivot, you might find that, if you cut the knife down, it ends up well below the blade in some cases.

These are two slightly different beasties. To me, a splitter is the huge contraption behind the blade (and extending well above it) which also mounts a clear protective guard over the entire blade. It is fixed, and doesn't move up and down with the blade. The clear protective guard lifts up just far enough to allow timber through the saw, covering the blade at all other times. My JET tablesaw came with this - I removed the entire thing, splitter and all. It got in the way for through cuts (restricted vision), and had to be laboriously removed for trenching cuts then replaced.

A riving knife has the same function, but is usually a shark fin shape the same heights as the blade, usually without any other protective device mounted to it. This moves up and down with the blade, meaning it doesn't interfere with through cuts or trenching cuts. I'll be looking for this feature on my next saw.......

I make my own zero clearance inserts anyway, so for through cuts I have one with a stubby (20mm high) wooden splitter just behind the blade. This prevents timber closing up on the back of the blade and kicking back. The stubby splitter thickness should be midway between the kerf thickness of the blade and the thickness of the sawplate itself - I made one for a standard kerf blade I use, and another for a thin kerf blade. For trenching cuts, as Lappa says, no splitter is required. I just use the standard insert that came with the saw, or a homemade one without any splitter at all.

As for the video, very poor control of the workpiece is to blame for all his mishaps. All part of putting the fear of god into people to promote the SawStop system. You should ALWAYS ensure that you keep the workpiece hard up against the fence at all times, and push right through the cut until the workpiece is well clear of the blade.

This video by Frank Howarth will enlighten you greatly! https://youtu.be/zNXuYlwI8N0

My table saw has a linear riving knife. i.e the distance between the top of the riving knife and the top of the blade (vertical distance) remains the same no matter what height you set the blade to.

Which is why I'm still confused as to why it would be designed with more riving knife material above the height of the blade. It serves no purpose IMO.

In any case. I think I will do what BobL said and buy a spare riving knife and modify to suit.

It's the difference between a splitter and a true riving knife.

I just realised the reason why the riving knife is higher than the blade height is to hold the finger guard..................
Makes sense.

Great table saw so far though. No complaints about it.