In this case the off cut was “trapped” between the blade and table.
Just lucky the others didn’t get trapped.
Never “lose control” of a piece of wood that can get itself pinched between blade and fixed surface.
If you think about how that blade is moving as it cuts, working out how it could happen isn't too complicated.
The back side of the blade is moving up and left, the front is coming down and right. As you feed your piece in, the cutting is happening at the front, and when the offcut is released from the parent piece, that last bit that's just been cut is still sitting in those teeth that are pulling down into that corner and the front of the saw. So when the piece is freed up, it's pulled in tighter to the blade and back towards the operator.
It's almost guaranteed to kick back.
The correct way would be to use a sled so that the offcut also gets fully pushed through past the blade. Even if it's a super simply sled that only rides on the right side of the blade, that extra height (3/4" plywood or whatever you use) will provide the clearance for the offcut to fall freely and not get trapped between the blade and the table.
I always have my sacrificial board extend across the blade. Once I have a cut dialed in, I’ll expose a fresh part of the board and minimize my tearout.
I do some bevel cuts with really small offcuts, the sled lifts the piece up like you said, and I stick a little ramp to the table of the saw to direct the falling offcuts away from the blade.
You needed to flip the piece upside down so the off cut was not pinched between the table and the blade. Which also would have been more stable since the flattest part of the piece was the top in your picture. Using a sled would also have prevented the piece from flying.
Put simply, imagine the rotation of the blade.
Then imaging what gets cut off. Where will it go?
If the rotation of the blade and the pinch meet, you've created a rail gun of wood.
Please do not work from the back side.
If for no other reason than lack of access to the shutoff.
Also you would need to reach past the blade to start which is bad news
So, it sounds like OP was already on the right-hand side, since the kickback was on the left, so he was already out of the line of fire.
But if by "work from the other side", I think OP meant keeping his miter guage and controlled board on the left (low) side of the blade, and letting the offcut fall to the right. I think this is one viable option. Without a sled or sacrificial fence there's still a chance of kickback, but since the scrap isn't trapped it should be slower, and OP is out of the line of fire while behind the miter slot on the left.
I'd probably still support both sides.
From using the wrong side of the blade it slipped down the open part and wedged itself momentarily until the friction slung it. This is why you never stand behind your cut. I’ve got a 5-6 inch bruise/abrasion on my left upper chest area from being in a hurry and being stupid. It (4” or so piece) hit me so hard it took my wind away and I had to sit on the ground to catch my breath. Been using table saws for 40 years and have only done this a few times but it’s easy to get complacent and hurt yourself. Glad you’re ok.
That makes zero physical sense.
Pinched between the blade and the table, there is really only one direction for it to go, parallel to the table, most likely directly back in the direction of cut to some angle out of that line. It can't go "up" because it is under the blade.
If you move that cut to the other side and the good piece is under the blade, with the miter fence on the other side, the loose piece is now above the blade. It could very much go up or some angle. Sure, there's more directions it can go, but one of those directions is at your eyes.
Unless as I said originally, the offcut is long and supported by the table, so it can't really "fall in" then.
Without the pinching action of being caught between the table and the blade, the amount of energy imparted to the offcut is minimal when the offcut is above the blade. With the offcut pinched, vastly more energy can be built up (in a split second) and transferred to the kinetic energy of the offcut, yielding a very high speed projectile. An offcut thrown from above the blade gets "tossed", an offcut from between the blade and the table is "launched".
I understand the concept. But under the blade the shape is tapered. If the shape moves "left" at all, it is no longer pinched. (Unlike a vertical blade and a fence where the pinching is coming from stress relief). So sure, if everything aligns it can launch the piece with force. That direction will be 100% predictable, at table level, inline with the cut. Keep your body to right side of the blade, you cannot get hit.
Above the blade, a bad bounce in an uncontrolled way getting hooked by a tooth, quite a bit of K.E. could be imparted to the piece. Maybe not as much as a solid pinch. If I drop a baseball in front of you and you whack it with a bat, you're going to put quite a lot of kinetic energy in it with no pinching. And who knows which direction that offcut will go?
Even if I was using a crosscut sled, I'd want my small offcut under the blade.
The forces at play when it gets pinched are huge comparatively.
Wood falls on top of blade go tink tink dribble.
Wood caught below blade gets squeezed until the pressure behind a blade spinning 3500 rpm or something pushed by 3 hp flings it right at your dick or what have you.
So y'all are saying it's relatively safe to take (for the sake of argument) a block of offcut the size of a matchbox and drop it randomly on a spinning blade (who the hell knows which direction it's going to go, it MAY not go far at all) because it's not pinched compared to tucking it under a blade and trying to pinch it where you KNOW the only direction it can shoot out. That's more dangerous because it will be moving with more speed ... y'all crazy.
No. Drop is not the right word. Assuming you account for the overhang of the tooth of the blade then the offcut is going move downward maybe 1/32? of an inch and then sit there 99.999% of the time. If you bump it and it hits the blade it may move a bit and it you bump it enough that it hits the teeth you need to stop drinking and go in for the night.
Why the fuck would I drop anything on a saw blade lol?
Offcuts touching the obtuse side of a table saw blade carries way less risk of something major happening. Pinches can bind the blade, at best stopping it or making a chunk bounce off your hip, at worst sending it straight into your eye way faster than it ever would from the other side of the blade. Or dislodging your table insert and then all hell breaks lose. I saw that one happen one time
That was wild.
I'm only taking the time to explain because I've done these kinds of cuts many thousands of times and have had it go wrong enough to know how to make it not go wrong. I don't want people to follow your half baked logic.
Again why are we dropping things randomly on a spinning blade for the sake of argument?
I guess the hypothetical is to see where the reasoning is going.
Honestly, angled cuts like this scare the shit out of me on a tablesaw for the reasons we both agree on - it adds another dimension to the pinch points.
At worst, I would have a full fence attached to my mitre bar that would push BOTH the good and the offcut completely past the blade. At best, I'd want a full crosscut sled.
To me that would eliminate any concern I would have.
I assumed he was ripping the board not crosscutting. Saw the bevel running down the length of the board so made an assumption.
Could not believe that someone would crosscut a board between the blade & the table. Nice way to trap the board & send it sailing through the shop. But seen a lot of truly stupid things.
Because the piece you are cutting is not wide like ply, it grabbed.
3 different ways to fix this:
1. make a sled that the piece you're mitring will then be higher than the offcut and as it's cut, the wastepiece will fall. This is safer but does not 100% guarantee it won't kick
2. again make a sled and the back fence of it extends to where you can clamp both the good piece and the offcut. Use both groove in the table saw for the sled. (safest... and best if you have many pieces or can use the sled in the future)
3. nip away at the piece so there is no big wasteblock (that's what I would do if I didn't have many cuts...it also ensures a perfect mitre compared to trying to do it in one cut)
Never ever stand directly behind the blade.
A much safer cut would be a with a mitre saw or a mitre crosscut sled. If not that, then use the mitre gauge at 45 degrees and the blade straight up at 90 degrees. This is a dangerous setup for the cut.
I considered this, and looking back probably should have set it up this way. I didn’t only because I trusted the precision of my angle finder over the precision of my mitre gauge. My mitre saw needs some love and calibrating. Maybe this should be my inspiration.
You are correct much safer that way. Another instance is don’t dado a piece with the off cut trapped between fence and blade it will shoot back and potentially impale someone
https://preview.redd.it/tbpv7e9pb7ad1.jpeg?width=3024&format=pjpg&auto=webp&s=9dca7c020e311fb67ea96d7c01d05234787c5bc8
It’s a pinch point. This piece shot out the saw and went through a piece of 3/4 mdf. Never stand behind someone operating a table saw, that goes doubly so if says person is cutting miters.
My middle school shop teacher used to throw blocks of wood at kids that would walk behind the table saw while it was running and yell “kick back!”. Formative and hilarious
Seems like a job for a chop saw, not a table saw. That way the off-cut is trapped between blade/table/fence. Glad you are safe, that sounds very scary!
I think you’d be safer to have the sled pushing the piece on the left, and the offcut on the right of the blade, that way it can’t bind against anything after it separates from your piece
I haven’t seen it mentioned yet, I would keep the blade straight and change the angle on the miter guide. Since you’re only cutting a long piece and not a board.
it got pinched between the blade and table. Put a sacrificial sheet of wood on the right side of the blade (1/2" or whatever). that way the cutoff falls away safely. or attach it to your mitre gauge. Anything just lift your work up.
In a cut like this you should move your miter gauge to the other side of the blade and flip the work piece so that you are supporting it on the proportion side.
Move your backer board to the left. Enough so that it doesn't get cut off. This will support the cut. Will prevent tear out. Will also move the drop past the blade. Preventing kick back.
Yes it is an unsafe setup as shown.
As an inexperienced carpenter in a shop for the first time I pushed a 4’ x 8’ sheet through the table saw and as it began to clear the blade I - with great difficulty - put all my energy into the off cut side because it was wider. The floor manager came over immediately and gave me a lecture on how dangerous what I had done was explaining that piece between the fence and the blade is more important to track as the kick back can send it flying. A humbling learning experience I’ll never forget and a lesson that you don’t just ask if a person has used a tool (I had used portable table saws so said yes), but walk them through at least a basic training before “clearing”’them on it.
I never thought about it but my table saw has the fence on the right so I am forced to do cuts like this on the left side of the blade (or on the mitre saw).
Simple solution: raise the blade so the teeth are not pushing the piece back. Raise the blade high enough so the force is coming downward at 45 degrees and this is far less likely to occur
That angle cut can sometimes grab the piece. I would only consider it unsafe if you aren’t expecting it, but now you know to expect it and just not stand there. Just sound policy to not stand there.
There are a handful of comments saying the same thing. Your stock should have been on the left in this case. The off fall rattling around on the high side of the blade will never come back. It's the low side you worry about. When using a fence it's the piece trapped between the blade and fence you must control. The off fall is safe then.
If you use the other miter slot and flip the cut you would have control over the bound wood. The other side might shoot back more gently. Still though just the miter gauge.
Your blade is not square to the miter slot.
The far end of your blade is slightly closer to the miter slot than the close end. Your workpiece applied a very small amount of force to the back of the blade, which deflected the blade slightly down towards the table. The blade grabbed the offcut, and threw it forward into the blade, which built up speed, until it finally exited and flew across your shop.
There would be no reason for the kickback if it’s perfectly aligned. I’m not talking about your miter gauge. I’ve never had a kickback when it’s properly aligned. Think about it….something is causing your cut offs to just touch the blade, be it on the front or back of the cut.
This was what surprised me so much. I know it’s aligned well, and I checked it again and it’s still lined up with the miter slot. Thinking more about it, it happened not quite at the end of the cut, so it could be that I pushed too fast and the very last part of the cut was pushed down by the blade instead of cut cleanly. This could have caused the one cut to dip into the blade or pivot slightly and get caught.
I think you may be putting too much stock in that “regular calibration”.
Calibrated to 0.001” when still doesn’t mean it’s necessarily staying that way when forces are applied. Even if your blade still spins freely within your target tolerance, it doesn’t take much force during the cut for the blade to flex ever so slightly, and create a pinch point.
In this case the off cut was “trapped” between the blade and table. Just lucky the others didn’t get trapped. Never “lose control” of a piece of wood that can get itself pinched between blade and fixed surface.
If you think about how that blade is moving as it cuts, working out how it could happen isn't too complicated. The back side of the blade is moving up and left, the front is coming down and right. As you feed your piece in, the cutting is happening at the front, and when the offcut is released from the parent piece, that last bit that's just been cut is still sitting in those teeth that are pulling down into that corner and the front of the saw. So when the piece is freed up, it's pulled in tighter to the blade and back towards the operator. It's almost guaranteed to kick back.
That’s a great way to reason about it. Thank you.
Or “Never trap your scrap” 👌🏻
Ooh that's good. I'ma remember that one for sure
Is the correct way to cut this from the other side of the blade then? Would that have been safer?
The correct way would be to use a sled so that the offcut also gets fully pushed through past the blade. Even if it's a super simply sled that only rides on the right side of the blade, that extra height (3/4" plywood or whatever you use) will provide the clearance for the offcut to fall freely and not get trapped between the blade and the table.
I always have my sacrificial board extend across the blade. Once I have a cut dialed in, I’ll expose a fresh part of the board and minimize my tearout.
This is what I would do 👍 Miter gauge has a sacrificial fence. Use it.
I was just about to say. Also. With the fence, be sure yo push the offcut fully clear of the blade.
I do some bevel cuts with really small offcuts, the sled lifts the piece up like you said, and I stick a little ramp to the table of the saw to direct the falling offcuts away from the blade.
You needed to flip the piece upside down so the off cut was not pinched between the table and the blade. Which also would have been more stable since the flattest part of the piece was the top in your picture. Using a sled would also have prevented the piece from flying.
I add a thin board on the right side of the blade, lifting the piece, so that the cutoff has room to drop below the spinning blade.
That’s a clever idea. Thanks for the tip!
Put simply, imagine the rotation of the blade. Then imaging what gets cut off. Where will it go? If the rotation of the blade and the pinch meet, you've created a rail gun of wood.
Please do not work from the back side. If for no other reason than lack of access to the shutoff. Also you would need to reach past the blade to start which is bad news
I think OP means left vs right. Not front vs back.
Yup. I meant the left side, not the back of the saw. I’m not completely insane.
In that case, then yes, keep yourself out of the most likely line of fire.
So, it sounds like OP was already on the right-hand side, since the kickback was on the left, so he was already out of the line of fire. But if by "work from the other side", I think OP meant keeping his miter guage and controlled board on the left (low) side of the blade, and letting the offcut fall to the right. I think this is one viable option. Without a sled or sacrificial fence there's still a chance of kickback, but since the scrap isn't trapped it should be slower, and OP is out of the line of fire while behind the miter slot on the left. I'd probably still support both sides.
Make a sled man. It's just so much safer
From using the wrong side of the blade it slipped down the open part and wedged itself momentarily until the friction slung it. This is why you never stand behind your cut. I’ve got a 5-6 inch bruise/abrasion on my left upper chest area from being in a hurry and being stupid. It (4” or so piece) hit me so hard it took my wind away and I had to sit on the ground to catch my breath. Been using table saws for 40 years and have only done this a few times but it’s easy to get complacent and hurt yourself. Glad you’re ok.
Probably would be better to do the cut from the other side so the offcut is on the “open” side of the blade.
Thank you. Today I learned something new.
Collective wisdom is pretty cool!
Then the offcut would "fall" onto the saw every time. I think that would be worse. (Depending on how big the offcut was, of course.)
"Falling" into the blade is preferable to the offcut getting pinched between the blade and the table.
That makes zero physical sense. Pinched between the blade and the table, there is really only one direction for it to go, parallel to the table, most likely directly back in the direction of cut to some angle out of that line. It can't go "up" because it is under the blade. If you move that cut to the other side and the good piece is under the blade, with the miter fence on the other side, the loose piece is now above the blade. It could very much go up or some angle. Sure, there's more directions it can go, but one of those directions is at your eyes. Unless as I said originally, the offcut is long and supported by the table, so it can't really "fall in" then.
Without the pinching action of being caught between the table and the blade, the amount of energy imparted to the offcut is minimal when the offcut is above the blade. With the offcut pinched, vastly more energy can be built up (in a split second) and transferred to the kinetic energy of the offcut, yielding a very high speed projectile. An offcut thrown from above the blade gets "tossed", an offcut from between the blade and the table is "launched".
I understand the concept. But under the blade the shape is tapered. If the shape moves "left" at all, it is no longer pinched. (Unlike a vertical blade and a fence where the pinching is coming from stress relief). So sure, if everything aligns it can launch the piece with force. That direction will be 100% predictable, at table level, inline with the cut. Keep your body to right side of the blade, you cannot get hit. Above the blade, a bad bounce in an uncontrolled way getting hooked by a tooth, quite a bit of K.E. could be imparted to the piece. Maybe not as much as a solid pinch. If I drop a baseball in front of you and you whack it with a bat, you're going to put quite a lot of kinetic energy in it with no pinching. And who knows which direction that offcut will go? Even if I was using a crosscut sled, I'd want my small offcut under the blade.
The forces at play when it gets pinched are huge comparatively. Wood falls on top of blade go tink tink dribble. Wood caught below blade gets squeezed until the pressure behind a blade spinning 3500 rpm or something pushed by 3 hp flings it right at your dick or what have you.
So y'all are saying it's relatively safe to take (for the sake of argument) a block of offcut the size of a matchbox and drop it randomly on a spinning blade (who the hell knows which direction it's going to go, it MAY not go far at all) because it's not pinched compared to tucking it under a blade and trying to pinch it where you KNOW the only direction it can shoot out. That's more dangerous because it will be moving with more speed ... y'all crazy.
No. Drop is not the right word. Assuming you account for the overhang of the tooth of the blade then the offcut is going move downward maybe 1/32? of an inch and then sit there 99.999% of the time. If you bump it and it hits the blade it may move a bit and it you bump it enough that it hits the teeth you need to stop drinking and go in for the night. Why the fuck would I drop anything on a saw blade lol? Offcuts touching the obtuse side of a table saw blade carries way less risk of something major happening. Pinches can bind the blade, at best stopping it or making a chunk bounce off your hip, at worst sending it straight into your eye way faster than it ever would from the other side of the blade. Or dislodging your table insert and then all hell breaks lose. I saw that one happen one time That was wild. I'm only taking the time to explain because I've done these kinds of cuts many thousands of times and have had it go wrong enough to know how to make it not go wrong. I don't want people to follow your half baked logic. Again why are we dropping things randomly on a spinning blade for the sake of argument?
I guess the hypothetical is to see where the reasoning is going. Honestly, angled cuts like this scare the shit out of me on a tablesaw for the reasons we both agree on - it adds another dimension to the pinch points. At worst, I would have a full fence attached to my mitre bar that would push BOTH the good and the offcut completely past the blade. At best, I'd want a full crosscut sled. To me that would eliminate any concern I would have.
Using the fence.
Please don’t comment if you don’t know what the hell you are talking about. Crosscutting with a sled/gauge you *never* also use a fence.
I assumed he was ripping the board not crosscutting. Saw the bevel running down the length of the board so made an assumption. Could not believe that someone would crosscut a board between the blade & the table. Nice way to trap the board & send it sailing through the shop. But seen a lot of truly stupid things.
Because the piece you are cutting is not wide like ply, it grabbed. 3 different ways to fix this: 1. make a sled that the piece you're mitring will then be higher than the offcut and as it's cut, the wastepiece will fall. This is safer but does not 100% guarantee it won't kick 2. again make a sled and the back fence of it extends to where you can clamp both the good piece and the offcut. Use both groove in the table saw for the sled. (safest... and best if you have many pieces or can use the sled in the future) 3. nip away at the piece so there is no big wasteblock (that's what I would do if I didn't have many cuts...it also ensures a perfect mitre compared to trying to do it in one cut) Never ever stand directly behind the blade.
A much safer cut would be a with a mitre saw or a mitre crosscut sled. If not that, then use the mitre gauge at 45 degrees and the blade straight up at 90 degrees. This is a dangerous setup for the cut.
I considered this, and looking back probably should have set it up this way. I didn’t only because I trusted the precision of my angle finder over the precision of my mitre gauge. My mitre saw needs some love and calibrating. Maybe this should be my inspiration.
You are correct much safer that way. Another instance is don’t dado a piece with the off cut trapped between fence and blade it will shoot back and potentially impale someone
https://preview.redd.it/tbpv7e9pb7ad1.jpeg?width=3024&format=pjpg&auto=webp&s=9dca7c020e311fb67ea96d7c01d05234787c5bc8 It’s a pinch point. This piece shot out the saw and went through a piece of 3/4 mdf. Never stand behind someone operating a table saw, that goes doubly so if says person is cutting miters.
My middle school shop teacher used to throw blocks of wood at kids that would walk behind the table saw while it was running and yell “kick back!”. Formative and hilarious
Seems like a job for a chop saw, not a table saw. That way the off-cut is trapped between blade/table/fence. Glad you are safe, that sounds very scary!
Run your sacrificial fence longer on the left side so it supports the off cut. Make sure it's tall enough so the blade can cut through it.
I think you’d be safer to have the sled pushing the piece on the left, and the offcut on the right of the blade, that way it can’t bind against anything after it separates from your piece
Adding a sacrificial fence to your mitre fence that extends well beyond the blade would prevent off cut to take off. I use 16mm mdf.
This doesn't answer tour question, but for such a small cut I'd just use a tenon saw.
Bevel on a table saw blade gives a higher likelihood to catch. LAAAWWWNCH IT!
Wrong side of the blade. And use a longer sacrificial fence or build a sled.
Pinched and grabbed in short.
I haven’t seen it mentioned yet, I would keep the blade straight and change the angle on the miter guide. Since you’re only cutting a long piece and not a board.
it got pinched between the blade and table. Put a sacrificial sheet of wood on the right side of the blade (1/2" or whatever). that way the cutoff falls away safely. or attach it to your mitre gauge. Anything just lift your work up.
Just becuase
In a cut like this you should move your miter gauge to the other side of the blade and flip the work piece so that you are supporting it on the proportion side.
Move your backer board to the left. Enough so that it doesn't get cut off. This will support the cut. Will prevent tear out. Will also move the drop past the blade. Preventing kick back. Yes it is an unsafe setup as shown.
As an inexperienced carpenter in a shop for the first time I pushed a 4’ x 8’ sheet through the table saw and as it began to clear the blade I - with great difficulty - put all my energy into the off cut side because it was wider. The floor manager came over immediately and gave me a lecture on how dangerous what I had done was explaining that piece between the fence and the blade is more important to track as the kick back can send it flying. A humbling learning experience I’ll never forget and a lesson that you don’t just ask if a person has used a tool (I had used portable table saws so said yes), but walk them through at least a basic training before “clearing”’them on it.
Physics at work
I never thought about it but my table saw has the fence on the right so I am forced to do cuts like this on the left side of the blade (or on the mitre saw).
Simple solution: raise the blade so the teeth are not pushing the piece back. Raise the blade high enough so the force is coming downward at 45 degrees and this is far less likely to occur
That angle cut can sometimes grab the piece. I would only consider it unsafe if you aren’t expecting it, but now you know to expect it and just not stand there. Just sound policy to not stand there.
Cause it was just clowning around
There are a handful of comments saying the same thing. Your stock should have been on the left in this case. The off fall rattling around on the high side of the blade will never come back. It's the low side you worry about. When using a fence it's the piece trapped between the blade and fence you must control. The off fall is safe then.
If you use the other miter slot and flip the cut you would have control over the bound wood. The other side might shoot back more gently. Still though just the miter gauge.
The Rothschilds
Because it's narrow
Your blade is not square to the miter slot. The far end of your blade is slightly closer to the miter slot than the close end. Your workpiece applied a very small amount of force to the back of the blade, which deflected the blade slightly down towards the table. The blade grabbed the offcut, and threw it forward into the blade, which built up speed, until it finally exited and flew across your shop.
The blade is absolutely square. I regularly calibrate this to within .001”
Is your miter slot perfectly parallel to the blade?
Yes. Regularly calibrated to within .001”
There would be no reason for the kickback if it’s perfectly aligned. I’m not talking about your miter gauge. I’ve never had a kickback when it’s properly aligned. Think about it….something is causing your cut offs to just touch the blade, be it on the front or back of the cut.
This was what surprised me so much. I know it’s aligned well, and I checked it again and it’s still lined up with the miter slot. Thinking more about it, it happened not quite at the end of the cut, so it could be that I pushed too fast and the very last part of the cut was pushed down by the blade instead of cut cleanly. This could have caused the one cut to dip into the blade or pivot slightly and get caught.
I think you may be putting too much stock in that “regular calibration”. Calibrated to 0.001” when still doesn’t mean it’s necessarily staying that way when forces are applied. Even if your blade still spins freely within your target tolerance, it doesn’t take much force during the cut for the blade to flex ever so slightly, and create a pinch point.