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Please explain the difference.

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Forum topic by papadan posted 02-16-2017 10:43 PM 746 views 0 times favorited 13 replies Add to Favorites Watch
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papadan

3173 posts in 3088 days


02-16-2017 10:43 PM

Topic tags/keywords: resource info table saw riving knife blade

Between a splitter and a riving knife on a table saw. Way back, for work/not pleasure, I had Craftsman and Skil benchtop table saws. They had anti kickback pawls and splitters on the blade gaurds. 18 years ago I bought my first serious (to me) table saw. A ridged portable with roll around stand. In comparison to my old work saws this thing is a Caddilac. The table size, fence system, miter gauge. and the blade gaurd has the anti kickback pawls and a splitter built in and everything about it STILL works perfect. Over the years people started talking about Riving knives. New saws were coming out with them and there were add on units for saws without. I think some people even drilled holes behind the kerf opening in their blade inserts to mount them into. So my question is what’s the difference between a splitter and a Riving knife. Aren’t they the same thing? I bought a new little cheapo Ryobi TS (yes-on purpose) The new redesigned blade guard and anti kickback pawls are an engineering nightmare that I am going old school on. This new saw does include a Riving knife that raises and lowers with the blade, it’s a good thing it can be loosened and not used. The original blade, as you all know was crap and I bought a new blade @ 1/3 the price of the new saw. On inspection the original blade was undersized in thickness. Not as thin as my thin kerf blade but not as thick as my standard blades. No problem, it’s scrap metal anyway. I had trouble with the first couple cuts I made because the wood hit the Riving knife and stopped. The riving knife is thicker than a normal kerf quality blade. A couple test cuts on thin pine hit the knife but I just slid it on through. A cut with 3/4” pine and a try with 1/2” oak, I was unable to slide the wood through the cut. I disabled the Riving knife for now and will probably remove for good. Help me understand what’s up.

-- Artificial intelligence is no match for natural stupidity!


13 replies so far

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lew

11705 posts in 3475 days


#1 posted 02-16-2017 11:12 PM

My understanding is that the riving knife raises and lowers with the blade. The splitter does not.

-- Lew- Time traveler. Purveyor of the Universe's finest custom rolling pins.

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pottz

1757 posts in 704 days


#2 posted 02-16-2017 11:13 PM

papadan your right about them they do the same thing,if your wood is hitting the knife and stopping its just too thick for the blade your using.micro jig makes an after market splitter that comes in a couple different thicknesses that you mount on your throat plate,there easy to just pop out when you need to do dados or whatever.they work great.

-- sawdust the bigger the pile the bigger my smile-larry,so cal.

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knotscott

7695 posts in 3096 days


#3 posted 02-17-2017 12:11 AM

They serve the same purpose, but have some differences. A splitter does not raise and lower with the blade, though some can tilt, and others are fixed in place. A riving knife raises, lowers, and tilts, and is generally in closer proximity to the blade. There are good and bad examples of both, so I don’t view either as absolutely better. A good riving knife is the better mouse trap IMO.

IIRC, UL approval required riving knives on all new saws after 2009.

-- Happiness is like wetting your pants...everyone can see it, but only you can feel the warmth....

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hotbyte

976 posts in 2696 days


#4 posted 02-17-2017 01:00 AM

The difference for me is I’ve left on and been using the riving knife on my Delta 36-725 saw. The splitter on my old Craftsman 113 stayed in a cabinet and was never used.

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papadan

3173 posts in 3088 days


#5 posted 02-17-2017 01:02 AM

OK thanks for the info so far. I have always noticed that my splitters are thinner than the blades, I can use a thin kerf blade on my ridged saw with the same splitter. If my wood has some internal pressure and wants to close up after the cut, the splitter helps a lot and prevents a lot of kick back. But it does let the wood close some and I have had binding and burning. I just went in and took a good look. My blockage is due to misalignment. I need to put about a 1/32 shim behind the blade to center it on the Riving knife and everything will clear. I wont do that though because I’m taking off the Riving knife. I mentioned the overengneered guard, it is three pieces, a center bar and two moveable clear plastic sides. Very wobbly and it actually mounts to the Riving knife, so the back of the whole guard moves up and down with the riving knife. You cannot lower the blade below table top because the guard hits the top and stops. Your have to remove the guard to lower the blade fully. How screwed up is that??? I have a simple guard with a Splitter and anti kick back pawls that is left from that old Skil work saw that I burned up back in the late 80s or so. I’m a pack rat, gave the fence and rails to guy a couple years ago. Thanks for the information people.

-- Artificial intelligence is no match for natural stupidity!

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runswithscissors

2490 posts in 1745 days


#6 posted 02-17-2017 05:36 AM

Shim the riving knife, not the blade.

If your riving knife is too thick, you can either get a thin kerf one from Ryobi (I can’t believe they wouldn’t make one), or make your own from 14 gauge mild steel plate. Another way is to cut one out of an old saw blade. Just be sure the body of the blade is thinner than your saw’s blade (don’t measure at the teeth, as they are wider than the blade body).

You should not need to remove a properly fitted and adjusted RK for most cuts, including non-through cuts (i.e. blind cuts). That is one of the main advantages of the RK.

As for anti kickback pawls, I have never been impressed with them. Seem too flimsy, and often in the way. The RK will prevent most kickbacks all by itself.

-- I admit to being an adrenaline junky; fortunately, I'm very easily frightened

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papadan

3173 posts in 3088 days


#7 posted 02-17-2017 06:01 AM

RWS, When I measured the RK is .02 thinner than the blade but the blade is offset a little to the RK. I will look at the possibility of shimming the RK but that still wont solve the guard having to be removed to lower the blade.

-- Artificial intelligence is no match for natural stupidity!

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Jim Bertelson

4081 posts in 2885 days


#8 posted 02-17-2017 05:34 PM

I use a bunch of different things on my table saws. Here in Anchorage, my old Delta contractors saw still has its original guard with pawls. I hot rodded the attachment mechanism so that I can put it on or off in 30 seconds or less. That means I am more likely to use it. However, I also have a Micro Jig set up. And I also have a Grr-Ripper. I use a large super sled a lot, so the Grr-Ripper is handy if I am going back and forth since I don’t have to install anything when I take the sled off.

In La Conner WA I have a Rigid TS. It has a riving knife. I also use a Rockler sled, that is much handier than I expected it to be, a lot. I also have a Grr-Ripper there. Mostly I don’t use the guard much on that machine, depending more on the Grr-ripper and the sled.

Much of the time, the old Delta guard and splitter work just fine, and it sure is easier to put on and off than the guard, pawls, and splitter on the Rigid. Each of those is a separate item.

If you like, Dan, I can split up these comments into multiple smaller comments to increase the traffic, but then I might consider sending you a bill… (-:

-- Jim, Anchorage Alaska

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pintodeluxe

5329 posts in 2533 days


#9 posted 02-17-2017 06:22 PM

I started with a Jet contractor saw and added a splitter built into the ZCI insert. It was a pain, and constantly binding up. Plus it was plastic and would break. Once the splitter got stuck in the kerf of a board, so I tilted the board off the saw. Big mistake! As I tilted the boards, it lifted the whole ZCI off the saw.

Now I use a Sawstop with built-in riving knife and the whole system works a lot better. The riving knife is a sturdy metal piece, and doesn’t seem to bind. You can use the riving knife for any operation except dado cuts.

-- Willie, Washington "If You Choose Not To Decide, You Still Have Made a Choice" - Rush

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runswithscissors

2490 posts in 1745 days


#10 posted 02-17-2017 09:05 PM

Hmmmm. Thought I answered your question about interference of the guard with lowering the blade. Apparently it got lost in the cloud, wherever that is.

Yes, if you leave the guard on the RK, it will prevent lowering of the blade unless it’s designed taller to keep it higher than the blade. But then you would lose one of the RK’s advantages, which is that you can leave it in place when doing non-through, or blind, cuts. Personally, I don’t use a guard, though I did get a freestanding over-arm unit off Craigslist. Haven’t installed it yet. That is one way to go. Many of us who have been around saws for decades don’t use the guards, largely because the standard model (pre riving knife) were in the way and poorly designed. I still have all my fingers, but can’t speak for the other guys (and gals). Use of push shoes (not sticks) helps a lot. When I was much younger, I would sometimes push through a board with barely enough room between the blade and the fence for my fingers (always gritting my teeth, of course). Hence my user name. But I got older and wiser and decided to keep my digits.

To lower the blade all the way, you will probably have to remove the guard (not the RK), but I don’t know how much of a PIA that is. I notice in Grizzly’s catalog that most of their photos of their saws show just the shark fin- shaped riving knife but no guard. But I know they do have a guard available, and the RK is a different shape for that kind.

-- I admit to being an adrenaline junky; fortunately, I'm very easily frightened

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papadan

3173 posts in 3088 days


#11 posted 02-17-2017 10:39 PM

Jim, Dammit man, just send me the bill for the laughs!

-- Artificial intelligence is no match for natural stupidity!

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Jim Bertelson

4081 posts in 2885 days


#12 posted 02-18-2017 12:38 AM

Giggle…

-- Jim, Anchorage Alaska

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AlaskaGuy

3051 posts in 2029 days


#13 posted 02-18-2017 08:26 AM

A real riving knife also sets very close to the saws blade. Most spliters I’ve seen set back further from the blade. Closer is better.

-- Alaskan's for Global warming!

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