I had a table saw accident last night and cannot explain why (no injury). I was rippling a small piece of poplar to 3/4″ width using a narrow push stick and a magnetic and plastic feather board. The feather board was in front (before) and aside of the blade.
Only the wood came in contact with the blade. I was a couple seconds in and the feather board exploded. The leading magnet held and the rear magnet moved to the left (away from the fence) scratching the table. I later found a small sliver of the wood 10′ behind me.
I am quite used to the saw and have used the feather board hundreds of times. The feather board is ~ 15 years old and the plastic is likely brittle.
I simply cannot explain my error and need to know. The saw is setup properly. The blade is parallel to the fence and the OEM riving knife is correctly positioned and thinner than the blade.
The attached photo shows the result. I’ve moved nothing.
Replies
I'm confused, what was the accident? Was there kick-back?
The feather board is destroyed. There was a small piece of wood that did land behind me but 95% of the piece cleared the blade. I just cannot explain why the feather board exploded.
You said that the plastic was likely brittle and very old. Maybe that's it. Plastic dry rot may be the culprit. Good to know.
My bet is that the small chunk you were ripping was rotated off the fence as it cleared the last fins of the featherboard... which would have been before it reached the riving knife. Your push stick held it down so instead of flying away it was forced back into the featherboard.
Glad to hear you're not hurt! What's the hole in your saw's top for?
Yes, that makes sense. There is evidence the wood rode up on the blade, I believe because the wood was soft and fractured during the cut.
The hole in the top is factory made, can't recall its purpose. I'll check next time in the shop. Avoiding the shop today. Thanks again.
Is that the piece you were ripping? I think that's the issue. I wouldn't run a piece that small through the tablesaw. Too much can go wrong. Maybe what MJ said.
If you are referring to length that makes sense. I grabbed it from the cut-off bin. I agree, it's too short. I won't make that mistake again.
My theory is that there was a kick back and the feathers tried to retain the piece but broke due to the force exerted on them, being brittle may have even part of the incident, it all happened in a split second.
YEP, It may be toast, but that feather board saved you from what could have been a serious injury. It did it's job.
Is that your push stick on the fence? Is it like the one attached? If it is, the push stick attached does not prevent the front of piece from being lifted from the rear of the blade, since all downward pressure is applied at the rear of the piece. Also the feather board is apply force on the edge by the rear corner.. if the front piece of wood starts to rotate into blade the feather boards is going to act like a pivot point for the piece of wood helping it rotate away from the fence and over the blade..
Yes, but that's not the push stick I was using at the time. The one I used had a slightly longer horizontal edge but obviously not long enough. I have a very beefy, long push stick but It was too wide to comfortably use for my 3/4" rip.
Funny, I cannot recall the last time I tried to rip a short board. I wasn't thinking of the physics. Lesson learned, thanks.
I agree, looks like kickback to me. Once the piece mostly cleared the featherboard but before it reached the riving knife, there was nothing to keep it from rotating into the blade. A lesson for all of us in why not to rip short pieces!. That the featherboard fins broke is beside the point, not a cause of the accident; the kickback was already happening at that moment. Thanks for sharing the story, and glad it was nothing worse!
Thank you. Now it makes sense, at the time I was confused. I feel stupid I didn't think of that earlier.
First off, glad you weren't hurt. I think the folks have done a pretty good job of reverse engineering what happened. The featherboard was inappropriate for that short piece but, thank goodness it was there. The piece probably kicked back into the featherboard and that saved you from a bruised belly.
Small part processing brings different safety items into the mix. The Grr-Ripper (shown here at the router table) is great for small item processing. A sacrificial push block can do the same for a number of cuts.
Another method for small parts is to bandsaw them close and edge sand or disc sand them to the line for final dimension. I personally prefer to cut small pieces off of a larger blank letting the off cut become the part.
I'm new to the bandsaw and frankly didn't think of that. Makes a lot of sense. For the pieces I was making - temporary feet for a cabinet - a bandsaw and a block plane would have been a much smarter choice.
Now that I've located the other part of the small board I was ripping (laundry room) I've taped them together and made notes on them so I never make that mistake again.
One thing I did learn and religiously practice is to stand far to the left of the blade at all times (I'm right handed) so that part I got right.
It's important to push down, to the right, and of course forward
On push sticks, I agree with the consensus that yours can't hold down the board to counter the lifting effect of the back teeth. You can easily make very effective push stick/hold downs on the bandsaw. I make several at a time and when making cuts that are narrow treat them as sacrificial. The ones I make put six inches of plywood (3/4) on the back of the board pushing down (with a little drop down at the rear to push the board) and have handles to keep your hand up and away from the blade and also providing the right pressure.. I can make two or three of them in ten minutes.
I'm with stevieray. I have several different push stick widths (3/4", 1/2", 1/4", etc) hanging adjacent to my tablesaw to accommodate my cuts. In order to help "push right"and keep the work piece against the fence, I attach a grippy foam strip to the bottoms. They take no time to make and are basically sacrificial.
Here are photos of a push "stick" pattern I've used for over 40 years, after a friend's father in law showed it to us. It allows pressure over a variety of spots on the wood, including the front/center. I make them out of plywood scraps, in batches, and give them away to people also. I try to cut a slight curve in the long bottom edge, so that it can contact the front and rear of the piece. I make the pushing finger at the back end different heights for different thickness of wood. I also use these at the jointer, with it in my right (rear) hand. I also sometimes use one in both hands to push against the fence as well as down and thru the blade.
I agree with others:
1) Glad you're not hurt
2) The piece is too short for tablesaw...almost certainly the cause of the accident
3) For pieces this short, or if anything funky about the size or shape, I use the bandsaw and then clean up the edge with a handplane---sander would work too.
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Oh man, I can't imagine the sequence that resulted in someone thinking an icepick was the best available option and trying it for the first time. Crazypants. I will respectfully take a hard pass.
Thank you all.
Small pieces can easily be precisely ripped with hand tools.
They are not without risk, as I almost lost my finger tip while flicking off some shavings from my router plane.
Good thing I had some steri strips to close that razor cut... :(
Stay safe folks. Always think safety first. Don't get into a zone where your mind wanders, you're too tired, or in a rush.
Happy holidays everyone!
It was probably the feather board that caused the problem in the first place. When the short piece cleared, the tension released caused the piece to snap to the side like the old game of tiddlywinks resulting in a kickback.
There is generally no good reason for using a feather board for ripping on a table saw. Particularly if using a riving knife.
Small pieces almost always cause a problem or danger and on almost any machine I can think of. Your hand is too close or the potential for the thing to go flying is all too likely. If I can on a table saw I will rip a small piece out of a larger piece of wood and stop the saw after I pass the saw blade then cut it to length. I have a sled with toggle clamps that can hold small pieces or I will make a special holder for a specific task. The problem is sometimes, since if it is only one piece ,to save time, one is tempted to do stupid stuff and i can be quilty of that myself.
I have two case hardened stories: My friends father was killed by slamming two hardened faced carpenter hammers together and chard hit him in the neck.
Another friend of mine was doing something with an anvil and a carpenter hammer. He hit the anvil with the hammer and one of the claws popped off and stuck into the ceiling! Amazed by the event and making a proper Darwin decision he did the same thing again just to see and the second claw broke off and lodged next to the first claw!
A proper ice pick is case hardened steel as are the teeth of most saw blades!
By the way - ever loose a tooth on a carbide blade? Ever find one? Where do they go and how fast did they get there?
Whether equipment failure or user error the problem is really that you used a big machine to do a small job without taking into account all the mathematical considerations necessary to make it safe!
The best reason to use John Economaki’s Bridge City Tools’ Ripmaster.
Or a band saw that is configured for Resawing.
Or a large (i.e., deep) Mitre Box (Stanley, Craftsman or European…I own two of the three).
Or…(cue the trumpets) a (Japanese-style) pull saw (along with a Squangle or SpeedSquare).
Summary: slow/manual is the Safe Method and Fast/Motorized is Not !
Correction on Bridge City sawing platform: name is JointMaker Pro not RipMaster. Apologies.
The good news is that you are not injured. Thank God for that. However, did you make sure the feather board is just in front of the blade to avoid waste getting in the way of the cut? That seems to be the only likely reason for the explosion.
I recently had a tablesaw accident caused by running too short a piece through the saw. It flew back and hit me in the chest - hurt like the dickens and knocked the breath out of me. I wonder if there is anything anywhere that says what the minimum safe length would be. My piece was 14 inches.
14 inches is plenty long. Look to your technique for the reason it kicked back. I have run MUCH smaller parts through the tablesaw. I don't think the bells would go off in my head before the board was shorter than it was wide.
At the risk of droning on & on & on .....
Once more I post the pic of a European style TS inclusive of various work-guiding stuff added to it to minimise the chance of kickbacks and similar events - and hopefully to eliminate altogether the risk of an injury should a kick-back occur anyway.
The hold downs are from a Veritas router table fence (no longer sold) and are made of spring steel. There's a pair of them: one to guide and hold the work going into the blade and a vertical-only hold down adjacent to the back of the blade where it rises out of the table They slide and lock in T-track on top of the fence.
Alternatives could be two-piece featherboards that hold the work piece to the fence but also down on to the table. I use a magnetic featherboard to press wider pieces to the fence, for example.
I tend also to keep the blade high, as a low blade can kick back from any section (from front to back) of the exposed blade as all the exposed teeth of a low blade are moving near-parallel to the saw top. A higher blade means the front of the blade will tend to press the workpiece down on to the table, not back at the operator.
The TS insert is zero-clearance, so no danger of narrow workpieces tipping down between the insert and the blade.
The TS also has various other safety stuff, such as the riving knife, blade guard and a blade brake that stops rotation in about one second after the red button is pressed. But it's the hold downs and the higher blade setting that prevent kickbacks.
Even if the hold downs somehow failed (and they haven't done yet) any kick back would miss me, as I'm always standing well to the left, behind the carriage rail for the sliding table, never in line with the blade. And using a suitable push stick from above as well as behind so even my arm is well above any kickback zone.
I can recall only two small pieces getting chewed in 25 years of using the TS to cut such pieces. Only the wood got chipped a bit, not the saw or me or anything else.
Lataxe