I keep reading that it’s important (safety-wise) to have a splitter on my TS, but I’ve never seen an explanation as to how/why the splitter makes the saw safer. Other than serving as the attachment point for the blade guard, I have no idea what the splitter is for.
Would someone please enlighten me?
TIA,
augie (who always uses the splitter even though he doesn’t know what it’s for)
Replies
The splitter prevents the piec of wood that you are cutting from "pinching" the blade. This "pinching" could result in kickback.
Augie, glad to hear you use the splitter even when "clueless" about its purpose in life. The splitter's role in preventing kickback is an essential one. You'll find a few people who don't use them, but most of us would strongly suggest you keep doing so.
Do a search using the word "kickback" and you'll find enough horror stories to emphasize the point.
The fact that you didn't know the purpose of the splitter causes me concern: Sounds like you've not done much, if any, reading on table saw safety. Do yourself a favor and buy one of the better TS books on the market, read through it, make yourself familiar with how you can improve your odds when working with this dangerous piece of machinery.
forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
Another proud member of the "I Rocked With ToolDoc Club" .... :>)
I personally think it's a safety hazard, I care to differ with you FG. In our shop we only put it on when it's neccesary. Especially when cutting smaller pieces. Augie may be better off without it in SOME cases.- Pricey
Pricey,
I really have to say, I think it's a bit irresponsible to tell a new woodworker to NOT use a splitter.
Edited 6/29/2004 4:12 pm ET by Matthew Schenker
pricey, splitters and the even better designed riving knife do have their uses. They can help prevent accidents caused by lack of attention to detail and carelessness, as reported in this thread. http://forums.taunton.com/tp-knots/messages?msg=18343.1
The person reporting that mishap could easily have done a bit of damage to themselves. Slainte.RJFurniture
Sgian,
Did you intend to point to the plug/switch message or the tablesaw saftey thread you and I once contributed to?Namaste,
Gary
http://gwwoodworking.com/
Ooops..... I should have read Pricy's thread more carefullyNamaste,
Gary
http://gwwoodworking.com/
Ha, ha, Gary. I pointed where I pointed. I found the irony beer spatteringly funny, if not strictly relevant to this thread. My keyboard and monitor survived with a wipe down with a cloth. Slainte.RJFurniture
Well next time, try pouring a little suds across the table, here. Mind you, certainly not while we're working with sharps. Namaste,
Gary
http://gwwoodworking.com/
I would be most interested in a list of specific cases where it's safer to not use a splitter. Thanks in advance.forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)Another proud member of the "I Rocked With ToolDoc Club" .... :>)
For the sake of safety I give FG, but I still feel the same way. Examples; You cannot use one when using a slide table. I don't use the splitter when using a miter gauge, screws up the cut and makes me nervous having to push the piece 6 inches past the blade having my short arm out there. The splitter to me is an added menace to a finished piece SOMETIMES gauging the wood with the anti-kickback device teeth which ruins your finish. Just some of the reasons why I don't use one all the time and how I feel about it. In my shop I have installed the easily removable type. It has a housing the stays with the saw but the splitter itself pops out with a release switch. I like it but rarely use it. I understand that kick backs happen and that's why I stand off to the side of the saw a bit. Essshhh- I am not convincing anyone here so I give up. Your right, bad advice for the most part. Everyone put your splitters back on then. - Pricey
Pricey,
I tend to agree with you that using the splitter with a sled or miter gauge is a pain...because of the prawns (sp?). I don't use a long fense with either of those operations and would think the splitter would be less necessary....but I don't know for sure and would be curious as to how others think
I agree there are times a splitter is in the way, your example of using a sled is one but let me point out there is little risk of kick back. For one thing the fence should be out of the way and depending on your sled design the cut material falls away from the sled. Nothing has a risk of binding.
You can't use it during dado operations. And when you need to make a very thin rip 1/4" or less. On thin rips if there long I like to have a helper assuring they don't fly back.
It don't hurt to wear a leather apron I certainly do.
I agree we can get extreme with safety but a splitter is far from extreme.
Pricey,
My splitter, or riving knife, works on my Felder when using its slider, and it would have worked on my Unisaw when I had an aftermarket slider in use. The knife and guard with dust collector is in service almost always on my sliding table saw. It's in use whether I'm ripping with the fence or using the slider. The only time I remove the knife is for ocasional power fed cuts when I don't want to take the time to remove one of the four wheels to make room for the knife. Thinking about that, I might change my lazy habit, because I probably take equal amounts of time to either remove the knife or the feeder's second drive wheel. In any case, the feeder prevents kickbacks, but without the knife the workpiece may still pinch the blade's trailing edge, leaving a less than desirable cut. The knife ensures a good, clean cut, especially with the feeder.
You can and should stand to the side if using a miter guage - or at any other time. You should never have to reach over the blade or stand behind and in way of its line of fire. This goes for any saw, and I've operated many of them. The knife is never in my way. Using a miter guage with an extended fence works, because the knife goes through the same height/width kerf in the fence as the blade does.
You can remove the kickback pawls in order not to ruin your workpiece or for the splitter to pass through a blade width kerf. If you can't remove the pawls, get a splitter, or riving knife, without pawls.
I use the riving knife with my sled for the same reason I could use one with an extended fence on a miter guage. The knife's top need only be a bit above the top of the blade (my Felder doesn't have miter guage slots, so I screw the sled to the slider).
In almost three years, I haven't had a kickback.... NONE.
Like Forest Girl, I defy anyone to suggest when it might be safer or produce better results to saw splitter-less, or any operation when it can't be used.
Namaste,
Gary
http://gwwoodworking.com/
Edited 6/30/2004 12:45 pm ET by Gary
Splitters prevent the kerf from closing in on itself after the wood leaves the blade. If that happens (the kerf closing in on itself), the piece comes off the fence. Two things happen, one of which is a sure thing.
First, because the wood comes off the fence at the rear of the fence, the cut is inaccurate and often more stock is taken off that is actually planned, or the cut is slightly angled. If I am not using a splitter (which is often the case), I simply adjust the width of the cut wider than planned and re-cut the stock a second time, taking off an eighth or so on the second time around to clean up the cut. I like doing this anyway, because I can control feed rate better and avoid wood burns. This is no big deal.
Second, if the kerf closing in on itself, and is off the fence, wild things can happen to the stock and there is a possibility of kickback. However, simple verticle hold downs will prevent that. The idea is to keep the stock on the table, and don't let it rise up. Another way to avoid kickback without a splitter is to use featherboards to keep the stock solidly against the fence at the blade level. This won't stop the kerf from closing it on itself, but will reduce that effect.
I haven't used a splitter in perhaps 25 years and have had only one incident with a table saw which was because I was stupidly trying to freehand some quarter inch plywood.
That being said, this week I am trying to install some aftermarket splitters on the Unisaw.
The Delta Beismeyer version is cheap and fairly easy to use but difficult to remove. So far it has bound up on me several times, making removal of the unit difficult for dado operations. It also is not designed for thin kerf blade, which makes it impossible to use for most of my blades. I don't care for it at all.
The Merlin Excaliber model is nice, and very very easy to use, but is poorly designed. The female coupler is mounted very high on the inside of the saw, and when any bevel cut is made, it swings up and makes contact with the blade insert. Excaliber's technical service recommends taking the table saw blade insert to a machine shop and having the ribs milled away. I recommend that they design the splitter for this model and pay attention to details. It is worthless without significant milling on your saw.
All this being said, splitters are a good thing. I just can not find one that be taken off easily or can work on bevel cuts.
Regards,
Boris
"Sir, I may be drunk, but you're crazy, and I'll be sober tomorrow" -- WC Fields, "Its a Gift" 1934
The solution I use is to incorporate aluminum splitters into various zero clearance inserts. A lot of the material I use is 3/8". I use a splitter that is screwed into the slot of a baltic birch insert. the splitter is around 3/4" high and is very close to the blade when the blade is around 3/4" to 1" high. The next insert has a splitter that is a little over 2" high. This system is used for general cutting.
For non-through cuts I use a commercial phenolic insert without a splitter. The original throat plate that came with my jet saw is used for cuts where the blade is tilted. I use a Forest 8" blade for most of my work, but when I have to use a 10" blade for thick stock, I have another birch insert with a splitter at 3" high. The splitter is attached by bending the metal 90 degrees and attaching with two screws. It is important that you check that the material you use is the same thickness of your blade. it also has to be at exactly 90 degrees to the insert.
I change inserts depending on what I am going to do. You really don't need the pawls, they can create problems with ripping thin pieces. I also use GRR-Ripper a lot and my sled slides right over the splitter with no problem. If you raise the blade a little too high you will get some sparks, but your blade will be fine, of course we don't do stuff like that.
Hope this helps.
Harold
Edited 7/1/2004 11:49 pm ET by haroldp16
That would be a good survey to take...I havent had a guard or splitter on a saw for 30 years,with no problems...Wonder what the percentages of those that do, and don't, are??
Do a search using the word "kickback" and you'll find enough horror stories to emphasize the point.
Despite what others say Augie, ForestGirl gives the best advice. I agree with some that the factory guard systems are a pain to take on and off. Due to my lazyness in the past I went without a guard. But after getting the wind knocked out of me more than a few times, I bought a splitter.
Trust me I have been witness to some of the most awful injuries. I have a Beismier splitter on my saw. It goes on and off in a second. Well worth the extra $40. bucks it cost me. There are others that cost more and they may be worth the extra money.
Look into it. I've seen loss of fingers, hands and even a testicle,( story for another day) due to carelessness that could have been prevented.
Good luck
Edited 6/29/2004 3:34 pm ET by JAGWAH
This subject has come up here before - check the archives.
I didn't use a splitter during the first 32 years of my 35 years as a professional woodworker; I've used one 95% of the time since then. I also use a guard, which is attached to the splitter, because it picks up most of the dust that shoots off the blade, and because it might save my fingers or someone else's. As was said here earlier, the splitter prevents wood from contacting the trailing edge of the blade. That can prevent kickback and it makes for straighter cuts. The splitter by itself won't give you 100% safety margin, but it sure is better than nothing. I use the splitter with and without a four wheel power feeder, and the feeder eliminates the need for kickback pawls.
Do the math: calculate the speed and force behind a kickbacked piece of wood. If you aren't good with numbers, then maybe the following story will jog your sense of safety. During the building of a 55-foot workboat, a workpiece kicked back from my 3-hp Unisaw, which was on the floor at the boat's bow. The sawyer was a seasoned boatbuilder and his son was tailing the pieces. The 2x3-inch x7-foot oak projectile hit and left a football size hole the concrete block wall ten feet behind the boat, and it dropped only inches from the elevation of the saw. Damn! We were lucky nobody got in the way. That accident happened when the workpiece trailing end tipped up and then came down onto the spinning blade. A properly mounted splitter, with its top edge above the blade, would have prevented the kickback.
I've seen numerous, potentially disastrous accidents resulting from kickback, both in my own shops as well as in the boatbuilding shops I've worked in. One resulted a knee replacement for a guy who wasn't even operating the saw! He was over twenty feet behind it. One of my own accidents (yes, there have feen a few), resulted in my being knocked unconscious after the small piece of teak hit me in forehead - that was a mere two years into my career. Why I didn't use a splitter earlier was a result of my own lack of safety education as well as my egotistical need to be macho. "Nah, I don't need one. I'm tough."
Namaste,
Gary
http://gwwoodworking.com/
augie
Posting late but let me throw my .02 in.
I recognize the standard splitter on most US style saws is a PITA, but it does what it is meant to do. It also gets in the way of many operations; dado, thin rips, some cross cuts, and that is why many take them off.
I have a Euro style saw and it has a "Riving Knife", a piece of steel plate .125" thick that moves up and down with the saw blade and the height of the knife can be set just below the height of the blade so less than through cuts can be made without removing the knife. It will also get as close to the fence as the blade so I can slice 1/16" strips off and still have the protection of the knife. I don't know why the US manufacturers don't add this to their saws. Except for design costs, I think it would be cheaper to produce than the current splitter/guard kludge you have now.
Also, if your saw doesn't have the capability of upgrading to a Bies after market splitter, there are many examples of how to make an integrated splitter/zero clearance insert here and on the web.
Use the splitter and save a garage door, or stomach, or dog, or whatever.
_________________________________
Michael in San Jose
"In all affairs it's a healthy thing now and then to hang a question mark on the things you have long taken for granted." Bertrand Russell
Hi Michael,
Attached are photos of my Felder's riving knife. It seems some here might never have seen one. Take a look.
I had to go to my neighbor's shop to see how his Unisaw might accept a Euro style riving knife. The machine's splitter attachment point appears to be a cast base, part of the trunion, which is perpendicular to the blade. There are a couple of threaded holes, evidently there to accept Delta's stock splitter. It seems to me you could use a stout piece of angle iron or make a weldament that would accept a stock Euro style riving knife. A knife could be ordered from any of a number of Euro saw manufacturers.
To give you ideas, I've included photos of the knife on my Felder. As you can see, the knife's position - up and down, and proximity to the blade - can be adjusted. It's best to keep the knife close to the blade's trailing edge. Your Unisaw attachment need have only up and down adjustment if you use single diameter blades. I use blades from 12-14" diameter on my Felder. I keep the top of the knife above the blade, for safety and so my slider's crosscut fence can pass under the guard/dust collector. I lower the knife to slightly below the blade top when kerfing. My saw, like most Euro saws, does not accept dado cutters, but Felder's latest machines do. Knives come in various thicknesses to match the blade's kerf. Lastly: like a scoring blade, the knife myst be perfectly aligned with the blade.
I hope this helps.Namaste,
Gary
http://gwwoodworking.com/
Gary
I have a MiniMax 300S and the knives are very similar.
BTW: If the Felder was $5,000 less, I would have gone for it. :)_________________________________
Michael in San Jose
"In all affairs it's a healthy thing now and then to hang a question mark on the things you have long taken for granted." Bertrand Russell
Hey Michael, I'm just up the street in Palo Alto. We should get together for a brew and tour each other's shop. My son is in Campbell and I've a potential project out near Alum Rock Park, so I regularly get into your neighborhood.
Namaste,
Gary
http://gwwoodworking.com/
Michael, I can speculate why manufacturers don't use a riving knife instead of a splitter as you describe. OHSA requires saws to have a splitter, though a riving knife as you describe would conform to the regulation. OSHA also requires a hood. I suspect that manufacturers believe it to be less expensive to combine the splitter and hood into one device which drives the splitter design to necessarily have to come up through the wood, preventing its use for operations such as dadoing. Since OSHA allows the hood and splitter to be removed for operations such as dadoing, manufacturers don't feel the need to design a safety device which can remain in place during dadoing.
So, I think cost drives the simpler one-device design, and also, I think manufacturers try to fully comply with the letter of the regulation and what it suggests as a solution and that it doesn't occur to them to seek novel ways of complying with the regulation which, though different, would actually be safer.
Wayne
Gary posted pictures of his Riving Knife/Hood combo. The setup on my MiniMax is similar.
I think either could be made for no more than the current Splitter/Hood combos on the US designed saws. There are actually less pieces to be manufactured/assembled.
As for dadoes, I take the knife off because my dado set is 8" and I use 10 or 12" blades rip/cross blades. It takes about 15 seconds to remove/replace the knife.
"I think manufacturers try to fully comply with the letter of the regulation and what it suggests as a solution and that it doesn't occur to them to seek novel ways of complying with the regulation which, though different, would actually be safer."
I agree with this!_________________________________
Michael in San Jose
"In all affairs it's a healthy thing now and then to hang a question mark on the things you have long taken for granted." Bertrand Russell
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