Riving Knife, Splitter and Safety

[Mike Gambone]

Newbie here, I've owned a Delta direct drive table saw for 20+ years, but want to get more into the woodworking hobby. This saw isn't great, would like to upgrade to a nice contractor saw or hybrid. I have never used the clumsy guard/splitter it came with as its impossible to see or measure where you are. And the fence is awful, but the unit has served its purpose and I've not gotten hurt or had issues as I'm pretty careful with it. A new Grizzly G0771 looks perfect, but quite a bit out of my range at the moment.

However, there is lots of used stuff on CL. So, the question is, how much is safety really improved on these new models as there seems to be plenty of older models out there without riving knives or splitters. There also seems to be an outfit that sells splitters, riving knives, guards for older saws, though they aren't cheap.

Any thoughts on riving knives, splitters, etc. is welcome as I'm getting confused on the real benefits. Thanks in advance.

Mike

[Warren Wilson]

I use my riving knife almost all the time. It's not instrusive and it quite effective in preventing kickback. Here is what Fine Woodworking published on riving knives a few years ago -- it's quite graphic and clear. http://www.finewoodworking.com/tool-guide/video/fight-kickback-with-a-riving-knife.aspx

I actually took delivery of a grr-ripper yesterday and used it for the first time today. Gotta say, it feels strange to run your knuckles above a spinning blade, but it seemed very secure and produced a nice cut right to the end.

[Kevin Jenness]

A splitter or riving knife is the most important safety feature on a tablesaw because they prevent kickback induced by work pivoting into the blade. Riving knives have been common on European saws for many years and are now found on newer saws made elsewhere. They work best because they maintain a fixed small distance from the blade. Splitters are independently mounted and thus the gap between them and the blade varies depending on blade height, but they are still a huge advance over no splitter. Bolt-on splitters are available for some saws, but almost all saws can be fitted with a wood splitter glued into a plywood zero clearance throat plate. If you are serious about upgrading your saw and have the budget for it, a newer cabinet saw with a riving knife is a good choice. If your funds are more limited, upgrade your old saw with a new fence and homemade splitter or find an old Powermatic 66 or Unisaw with a Biesemeyer or Unifence or such and put a Biesemeyer snap-in splitter on it.

Most shops with older saws threw away the combo guard-splitters for the same reason you did, but the baby went out with the bathwater. Using a splitter and a push stick and an awareness that your saw wants to eat your fingers will enable counting to ten digitally for a long time.

[Mike Gambone]

Great input guys, also super video, I understand the issue a lot better now. Need to think about this in terms of what I can spend a bit more.

[John K Jordan]

...find an old Powermatic 66 or Unisaw with a Biesemeyer or Unifence or such and put a Biesemeyer snap-in splitter on it.



Do you know where this splitter can be bought? I recently uncrated a brand new "old" PM66 and looked in vain for this. I read somewhere that it is no longer made. I do have an Excalibur overarm for dust and guard and I'm unbolting and bolting the cut-down factory splitter as necessary. This is a pain.

JKJ

[Roy Turbett]

Do you know where this splitter can be bought? I recently uncrated a brand new "old" PM66 and looked in vain for this. I read somewhere that it is no longer made. I do have an Excalibur overarm for dust and guard and I'm unbolting and bolting the cut-down factory splitter as necessary. This is a pain.

JKJ

Check out this website

http://www.mikestools.com/anti-kickback-spreaders_1047.aspx

[Dennis Aspö]

Any thoughts on riving knives, splitters, etc. is welcome as I'm getting confused on the real benefits. Thanks in advance.

My advice is forget splitters, a true riving knife is what you want. It will sit a hair below the blade and it will rise and lower with the blade, as well as tilt with it. It provides a solid protection against kickbacks and doesn't gets in the way even for trenching cuts because it doesn't protrude above the table. It's a set & forget safety feature, which is the best kind.

[Michelle Rich]

I have been running for 28 yrs a delta contractor saw & have zero safety stuff on it..just naked blade.. Amazingly I still have 10 fingers. But I am very careful and use a Gripper or push sticks. But just one moment of distraction & that could change fast. I checked out the link above & no help there..most all listings are no longer made. A new saw is not feasible at this time. Any other suggestions/links to an aftermarket item?

[Robert Engel]

1. You can make your own splitter that actually works like a riving knife.

2. The company that make the Gripper also makes the MicroJig.
I have one and it works good.

These are certainly no subsitute for a true riving knife but if, like me, you have a really good but older cabinet saw, you wouldn't buy a whole new saw for a riving knife, right?

[Kevin Jenness]

It appears the Biesemeyer unit is unavailable- too bad. It may be that the liability was too great to make such an item now that riving knives are available (required?) on new saws.

It is easy to make a working splitter by gluing a wood fin into a plywood throat plate. It's not a true riving knife, but far better than nothing. If the original combo guard is available the blade cover can be stripped off it to make it more usable.

[Mike Berrevoets]

+1 on the micro jig mj splitter. I used one for about 10 years on my old ridgid contractor saw. Made zero clearence plates out of Baltic burch and used both the regular and thin kerf models of the mj splitter. At the time I didn't have the money to upgrade the saw to one with a riving knife and I had installed a biesemeyer fence so the old splitter wouldn't work anymore.

But, it only works if it is being used. There was a time I was trimming up about a 18" square sheet of 1/4 ply when I didn't have the mj splitter in and I must have twisted/rotated the ply a bit. Wood grabbed the back of the blade and sent the square saucer flying around the shop. Missed me but scared the crap out of me. To be honest I really don't know exactly how it happend because it happened so fast. The ply had a nice half moon saw mark on the underside. I wrote "KICKBACK SUCKS!" With a sharpie on the piece an nailed it to the wall in front of the saw to remind myself not to be a dummy. I've since upgraded the saw but the board still resides on the wall. Even that famous "safe" saw wouldn't have stopped my dumb move if the riving knife isn't installed.

[John K Jordan]

Check out this website

http://www.mikestools.com/anti-kickback-spreaders_1047.aspx


Thanks, but that was where I looked before following a Google search. It still indicates "no longer available." If I can find someone who has one for the PM66 maybe I can measure it and machine one. Meanwhile I just got the little Micro Jig kit so I'll give that a try.

JKJ

[Rod Sheridan]

Newbie here, I've owned a Delta direct drive table saw for 20+ years, but want to get more into the woodworking hobby. This saw isn't great, would like to upgrade to a nice contractor saw or hybrid. I have never used the clumsy guard/splitter it came with as its impossible to see or measure where you are. And the fence is awful, but the unit has served its purpose and I've not gotten hurt or had issues as I'm pretty careful with it. A new Grizzly G0771 looks perfect, but quite a bit out of my range at the moment.

However, there is lots of used stuff on CL. So, the question is, how much is safety really improved on these new models as there seems to be plenty of older models out there without riving knives or splitters. There also seems to be an outfit that sells splitters, riving knives, guards for older saws, though they aren't cheap.

Any thoughts on riving knives, splitters, etc. is welcome as I'm getting confused on the real benefits. Thanks in advance.

Mike

Hi Mike< there's nothing new about riving knives or blade guards, they've been around for almost 100 years.

A riving knife or splitter is required to keep the work piece from rotating into the rear of the blade, which will result in a kickback.

A blade guard has the primary purpose of preventing contact with the top of the blade by a work piece which also results in a kickback. (This type of guard is called a crown guard and is common everywhere except in North America)

Note that both the guard and splitter/riving knife have the primary purpose of preventing kickback.

Kickback can result in serious internal injuries to the operator, in addition to the possibility of having a hand forced into the blade.

A riving knife/splitter and guard should always be used for all through cuts, no exceptions.

On non through cuts such as rebates, grooving, dadoes etc. an overhead guard should be used.

Don't operate a saw without guards and a riving knife/splitter...............Regards, Rod.

[Prashun Patel]

If you are taking the time and $$ to upgrade, my advice is to get a saw with a true riving knife - not just a splitter. I have a Sawstop (which has the flesh-sensing technology) but its most important safety feature is the knife.

Further, look for a saw that allows a tool-less switch between the guard and the riving knife. This will make you more prone to use the right device at the right time.

I would trade extra horsepower and flesh-sensing technology for a proper riving knife.

There is a plethora of old saws on the market precisely because rk's became more of a norm a couple years ago.

That G0771 is on sale right now, you know, and a new hybrid saw well south of $1000 is hard to find.

Keep using your existing saw until you can afford the right one.

[Brian Tymchak]

+1 on the micro jig mj splitter. I used one for about 10 years on my old ridgid contractor saw. Made zero clearence plates out of Baltic burch and used both the regular and thin kerf models of the mj splitter. At the time I didn't have the money to upgrade the saw to one with a riving knife and I had installed a biesemeyer fence so the old splitter wouldn't work anymore.


+2. I installed the microjig splitter on my contractor saw after putting the Incra fence system on. I didn't want to cut the rear fence rail to allow the use of the OEM splitter/guard. I would still like a cover guard over the blade on occasion, and I might eventually spring for an Excaliber at some point if I don't upgrade the saw first. But the splitter is a nice inexpensive solution. I've seen it work first hand. I could see the kerf close up behind the splitter as I was ripping down some 2x4s.

[Robert LaPlaca]

I have a mid-90's Unisaw, installed a Beismeyer splitter right after the purchase of the saw..The benefits of a splitter is it keeps the kerf from closing behind a rip cut, this happens from reaction wood, the splitter also prevents stock from rotating from the fence into the back of the blade, both of these scenarios are leading up to a kickback situation.

A riving knife does everything a splitter does, but does it better. It's closer to the back of the blade, it moves up and down with the height of the blade.. So it gets in the way less frequently, which means it gets used more..

I use the Beis splitter on as many cuts as I can, the one place where the Bies was wanting was with narrow rips, the type when I am making small molding.. Recently installed a MJ splitter on the saw also, use the Beis splitter for wider rip cuts where it does interfere and use the MJ for narrower rips. Have the MJ installed on a zero clearance insert that does not have the slot to accommodate the Beis

I did notice that Beismeyer doesn't seem to manufacture either the snap in splitter or the overhead guard..

[Henry Kramer]

I didnt see anyone mention the Shark Guard but in case I missed it I appoligize for being redundant. I purchased one of these about a year ago for my PM66 and I am very satisfied with both the splitter and the effectiveness of the clear plastic guard and it's dust removal ability. http://www.thesharkguard.com/sharksplitter.php

[Mike Gambone]

Wow, thanks everyone for the great info, thinking I'll slow down until the right machine (or money) shows up.

[Mike Gambone]

OK, looking at the Sharkguard link, it appears that riving knives are available for many old machines. Anyone have a comment on this, not sure how the knive would be installed, but this might offer a way to keep old saws (and budget) under control. Thanks again for all the info.

[David Kumm]

Many of the old cast iron saws did have true riving knives but you are not likely looking for a 2000 lb machine with three phase. Most hobby or smaller 10" machines had splitters which as others have said can be made to work just fine. I made a special splitter for my Whitney that only sticks up 1/2" so it seldom needs removal. I'm likely in the minority but don't thank an overhead guard is always most safe. My preference for short boards is the GRR with the blade set only 1/4" or so above the board. I control the board better ( my opinion only ), can see the cut, and don't have the tendency to push the stock off line like a push stick can. Again, just me. For long stock, I like a fence that ends just beyond the front teeth so there is no way to bind up after the cut. I would also tell you that a good fence, solid trunnion, and high enough motor so the saw doesn't bog down or vibrate may be a bigger deal than riving vs splitter if the design is good. Dave

[Mike Heidrick]

Is the **** still made - Bolt On Riving Knife? Google it.

[glenn bradley]

Views on safety are as varied as woodworkers. IMHO proper alignment, a ZCI and a splitter are your minimum safety items for a tablesaw. Commercial "guards" were tragic and less safe than not for many years. One falicy is the thinking that you need to "see" the blade during a cut. The blade will be right where it is supposed to be and, like the jersey wall on the freeway, will not suddenly move ;-) Easily moving the guard to see the blade during setup is, of course, desirable.

There are many inexpensive after-market splitter solutions for used saws. You will probably make your own ZCI's anyway so something like the MJ Splitter (http://www.microjig.com/products/mj-splitter/design-concept.shtml) (I used one for years) or your own shop-built solution (http://i257.photobucket.com/albums/hh224/grkemper/misc/IMG_0088Small.jpg) would be great.

My current saw has a riving knife and I love it. The aftermarket splitters work at 90* where the RK raises, lowers and tilts with the blade. the only time I remove it is to use the overarm dust collector that fits in the same socket and employs it's own RK.

The choice will have to be your own but, I would be comfortable with a splitter. The RK is safer and more convenient but, there are a lot of conveniences I do without in my shop ;-)

[Mort Stevens]

The choice will have to be your own but, I would be comfortable with a splitter. The RK is safer and more convenient but, there are a lot of conveniences I do without in my shop ;-)

I used a Unisaw for 30+ years with a splitter and anti-kickback pawls I don't know how anyone can say that a riving knife is safer.... unless I don't understand what exactly you guys are calling a riving knife;. In my mind a riving knife just keeps the kerft open, while a splitter does that plus adds the pawls for kickback? I don't see how without the pawls is anyway safer?

My new Powermatic saw came with both and I use the splinter exclusively, but if you guys can some how convince me I'm wrong, I'll switch to the riving knife.

[Kevin Jenness]

I have had anti-kickback pawls on a Delta disappearing splitter and Biesemeyer snap-in splitters. I have also used riving knives without pawls on several sliding table saws, and I don't feel the pawls add anything to a functioning splitter/riving knife, in fact they get in the way on narrow rips. The main function of either splitting device is not only to keep the kerf open but to prevent the stock from rotating into the blade and launching back at the operator. If it achieves that, the pawls are unneeded. And they need to be kept sharp to work- the Biesemeyer pawls are soft steel and need periodic filing to be effective.

[Jim Dwight]

One inexpensive saw you can find used is a Ryobi BT3100. The BT3000 is similar but some have 13A motors, the BT3100 is 15A with a better shim design that is relatively trouble free. It looks somewhat like your Delta but it is belt driven (about 3.5 inch depth of cut) and has a fence that stays parallel and looks at both ends. It doesn't have a miter slot, it has a sliding table (but a small one). I've had one for about 15 years and made several bedroom sets and lots of other furniture on it. I was thinking of upgrading but I also have a track saw and I use the table saw less now so I probably won't. New the BT3100 was $300 at the end (the BT3000 came out at about $750). So you ought to be able to pick up a used one pretty reasonable. It has a riving knife design but you have to do a little work to take the guard off the knife. There is also some aftermarket support including a "shark guard" which goes on and off nicely. The same outfit sells a riving knife you don't have to mess with.

[Mike Gambone]

Guys, thanks, I've got plenty to go on now, though I did note the Grizzly G0771 is on sale...... I really appreciate the help on this.