# Tablesaw chucked a scrap piece my direction....



## schnitz (Sep 5, 2009)

Luckily, it's only a couple smaller-ish cuts caused by the contact between the plywood cutoff and my finger & one knuckle. That could have been tons worse. I'll post pictures tomorrow, after the bleeding stops (and I can get my GF to take the pictures-- she's squeamish about blood...)


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## woodnthings (Jan 24, 2009)

*we know what it wasn't ....*

It wasn't a closed kerf, pinched blade type of kickback.
Right? 


It was probably a rotational one, where the piece rotated up and over the top of the blade and shot it back at you.
It will be interesting to hear how it happened, much more so than looking at your wounds..... just my opinion.:blink:

Also of interest would be if you have a splitter or riving knife on the saw. I feel much more confident using my saw with the splitter on than off since it does maintain the material against the fence and will prevent a rotational kickback. Don't ask me how I know this. :no:
I've had more than few pieces come back at me, and most were plywood. Then I put the splitters back on and not a single kickback since.


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## schnitz (Sep 5, 2009)

You nailed it. Typically, I shut the saw off, and let it spin down before removing the scrap. Rotational spin doesn't even come CLOSE to describing how rapidly that piece flew at me.


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## woodnthings (Jan 24, 2009)

*removing the off fall/scrap*



schnitz said:


> You nailed it. Typically, I shut the saw off, and let it spin down before removing the scrap. Rotational spin doesn't even come CLOSE to describing how rapidly that piece flew at me.


Depending on the size, length and width of the scrap there are a few ways to safely get it out of the way.

You can use a long push stick and push it way beyond and to the left of the blade.... even off the table entirely.

By the time the cut off is "free", it's location is at the center of the blade, too close and dangerous to remove it by hand. If the piece touches the blade with any force it will shoot back. 

You can use the next piece to be cut to push the initial piece along and off the table.

You should NEVER reach over or around a spinning blade to remove either the save piece or the cut off.
This means a totally stopped blade, not just one that is spinning down.

I have located my on/off switch at a height where I can bump it off with my hip. This allows me to keep both my eyes and hands where I can see the blade, the cut off and the work.Then after the blade stops, I can safely remove any scraps and the workpiece.


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## schnitz (Sep 5, 2009)

For clarification, by "spinning down", I meant "spinning down to a stop", not like as in just slowing down. This scrap piece measures 24" by 23 7/8" by 1/2" (plywood). 

You mention "scrap on the left". Am I doing this all wrong? I have always ended up with my scraps on the right side of the blade, making my cuts with the fence on the left of the blade (the fence was totally off the saw for this cut, and I never use it and the miter at the same time.


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## FrankC (Aug 24, 2012)

I never like to use the miter gauge with panels that size, sled works much better, no need to post photos of injury for my benefit.:icon_smile:


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## schnitz (Sep 5, 2009)

I didn't have a sled large enough to cut this one. And I'll post the pictures in the "lets see some damage" thread.


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## d_slat (Apr 10, 2012)

schnitz said:


> You mention "scrap on the left". Am I doing this all wrong?


There really isn't a right or wrong side to use. Most newer tablesaw are set up with more table on the right or more fence rail for you to put a table extension in. That along with a left tilt blade can make some operations easier or safer to do with the scrap left of the blade. That being said, many older saws are right tilt, and you can easily set your saw up to cut however you prefer.


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## schnitz (Sep 5, 2009)

Thanks d_slat, I actually went on YouTube and watched a few snippets of people using table saws. All but one cut were made opposite of how I use mine. Made me a bit uneasy about whether I was doing it wrong...


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## woodnthings (Jan 24, 2009)

*most all new saws are left tilt*

Newer saws come with more rail to the right for this reason, the blade tilts to the left. The cut off falls to the left of the blade. The fence is to the right of the blade, because that's where the most rail length is AND most all users are right handed, 70 % to 90% of the population according to Wiki.











You can't hardly find a new right tilt saw these days.

So there you are cutting your panel or ripping your piece down the length. You atre standing slightly to the left of the blade, your right hand is pushing forward and in towards the fenc at the same time. You left hand is assisting in the case of a wide panel or waiting to turn the machine off on a rip.

When the piece reaches the area of the throat plate you grab the push stick which is sitting on the fence bar and push the piece all the way through beyond the blade and onto the catch table or off feed support. Hopefully you have a splitter or riving knife in place to:
1. keep the kerf on from closing, pinching the rear of the blade and stalling the saw, OR kicking it all back towards you.
2. to maintain registration against the fence if only very slightly .... no pressure applied....it just can't walk away.


Whether you have a blade cover/guard or not is up to you. Murphy's Law says "If you CAN put you fingers into a spinning blade, you just might..." 
I personally don't like big plastic, blade hiding covers and just use a sandwich of 3 thin pieces of hardboard on a pivot with a friction bolt on my splitter, so it stays at what ever angle I leave it. Splitters don't allow partial depth cuts, but riving knives, new saw have them, that rise and fall with the blade do! 

Here's a photo of my table saw(s) showing a blade cover, not the one I described above, but it works OK:









Now don't get alarmed because the fence is on the left side of one of the saws, it's on the right side of the left saw...two fences, two saws.:blink: well actually 3 saws.


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## NickB (Sep 24, 2013)

woodnthings said:


> two fences, two saws.:blink: well actually 3 saws.


You woodnthings, are the epitome of everything that I aspire to be.


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## woodnthings (Jan 24, 2009)

*I started out small*

LOL :laughing:

I had an 8 1/4" Skil saw, a stamped sheet metal table, a 3/8" corded drill, a hammer and a egg beater drill and a dull crosscut saw...... Ma, look at me now!
Now, so many hammers I can't count, a bevy of circular saws, more table saws than I will admit... same for RASs, bandsaws, drill presses, saber saws etc.. and ...wait battery powered stuff upstairs and downstairs.
It only took 50 years to amass that collection, and the kid will sell most of it when that day comes.

The old Skil saw still saws...... I can barely lift it now.:yes:


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## JimGnitecki (Dec 5, 2015)

NickDIY said:


> You woodnthings, are the epitome of everything that I aspire to be.


Yes, I agree! WoodnThings you do things RIGHT.

Jim G


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## hwebb99 (Nov 27, 2012)

I had the same thing happen. I was cutting a piece wider than the fence could handle, so I had to subtract the difference and cut. This put the good piece on the left and the scrap better the blade and the fence. As soon as the cut was completed the blade pulled the scrap backwards and it got turned sideways. You can guess what happens next. Lucky no blood was spilled. I grabbed my dial indicator and checked the alignment of the saw. The back of the blade was 5 thousands closer to the fence than the front. I adjusted it so the front was .002 closer than the back. This fixed the problem and increased cut quality.


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## schnitz (Sep 5, 2009)

In case you may have missed it (since not everyone reads the "last person" off topic thread....), I had a much worse one than my TS getting me. While at work, I had a ~75 lb window sash slam shut on my hand. 6 stitches on the middle finger of my left hand. My "medication" wore off, and it's throbbing like a mother effer now. I wish I could redo THAT prescription! Lol!!


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## hwebb99 (Nov 27, 2012)

I wouldn't use sandpaper. Sometimes I cut my push stick, and sandpaper isn't blade friendly.


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## Brian T. (Dec 19, 2012)

Always stand just a little to the side of the work-line of a TS.

Many years ago, friend needed a place to store a 12" 220V TS. I had a 1,200sqft basement to finish.
Everything from finishing, to a gun cabinet to a doll house for my kids, I had a great experience.
Ripping a 2x4 one day. Standing behind the piece. Good ol' TS decided to spit that thing back at me, perfect crotch height. Thought I could get work, singing with the Geneva Boys Choir.


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## woodnthings (Jan 24, 2009)

*2 x 4 's are the worst*



Robson Valley said:


> Always stand just a little to the side of the work-line of a TS.
> 
> Many years ago, friend needed a place to store a 12" 220V TS. I had a 1,200sqft basement to finish.
> Everything from finishing, to a gun cabinet to a doll house for my kids, I had a great experience.
> Ripping a 2x4 one day. Standing behind the piece. Good ol' TS decided to spit that thing back at me, perfect crotch height. Thought I could get work, singing with the Geneva Boys Choir.


Quite often construction lumber in a 2 X thickness will either open or close behind the blade... reaction wood.:thumbdown: A splitter probably would have prevented that occurence.

I'm wondering which piece shot back at you, the fence constrained piece or the off fall piece?


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## epicfail48 (Mar 27, 2014)

Robson Valley said:


> Always stand just a little to the side of the work-line of a TS.
> 
> Many years ago, friend needed a place to store a 12" 220V TS. I had a 1,200sqft basement to finish.
> Everything from finishing, to a gun cabinet to a doll house for my kids, I had a great experience.
> Ripping a 2x4 one day. Standing behind the piece. Good ol' TS decided to spit that thing back at me, perfect crotch height. Thought I could get work, singing with the Geneva Boys Choir.


Holy mother of god, I cringed so hard reading that... Hope the, er, 'boys' recovered alright


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## Brian T. (Dec 19, 2012)

No, man, I didn't get the chance to finish the cut. 
Maybe a 24" piece, half cut before the low blow.
Happy to say that I'm not shooting blanks.


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## Brian T. (Dec 19, 2012)

Just in case you need some entertainment and would like to see some serious 2x4 action. Google around for Survival Research Labs and take a look at The Pitching Machine. As originally set up, it used a Cadillac Eldorado engine to throw 6' 2 x 4's about 1/sec on full auto and at approx 200mph.


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## woodnthings (Jan 24, 2009)

*Like I said in Safety Tips Thread ...*



Robson Valley said:


> No, man, I didn't get the chance to finish the cut.
> Maybe a 24" piece, half cut before the low blow.
> Happy to say that I'm not shooting blanks.


Most kickback occurances/accidents don't get reported because there is no blood and no stitches are required, BUT they can be near fatal. A mill operator with years of experience, I know got speared in the gut by a tablesaw kickback. It was serious and he had a long recovery period. Like they say in motorcycle riding ...if you haven't crashed yet, it's only a matter of time. If you haven't had a tablesaw kickback, it's only a matter of time.

Fortunately, blood spilling and tablesaw amputation accidents are far and few between. :yes:

My guess on the kickback described above it was a blade pinching incident, and the workpiece rose up and over the blade and was propelled toward you. Splitters are used to prevent this type of occurrence as well. I didn't use a splitter for years and then I understood their function and reason for being. Now I always use mine whenever possible.


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## Brian T. (Dec 19, 2012)

Yeah, I didn't know what those things were for until I bought my own TS (Ryobi $100) and was tempted to take it off. I do for short cross cuts. However, when I cut 100 birch blanks 7/8" sq x 14" for wood carving spoons & forks, that "riving knife"(?) was snugged up tight. I cut the 6/4 birch to 14" and then rip a pile of that. 70 spoons and 30 forks and I don't care if I ever carve another one in my life.
In any case: don't stand in the line of fire.


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## sawdust703 (Jun 27, 2014)

I've got a Craftsman 8" 1950's era table saw that the previous owner replaced the old motor w/a 2 hp motor. It does me a good job, no bigger than it is. I don't have a need for a huge table saw, but use this one regularly. No, it doesn't have a splitter, or a blade guard, or anything else safety minded on it. It has its purpose, & that's that. There's things I do with my saw that I wouldn't allow anybody else to do, simply because I trust the saw, & stay out of the line of fire. Make no mistake, That ol' fella has given me a kick back or two, but nothing serious. I still have all my fingers! Table saw safety is something that is often forgotten about until an accident happens. Learn to respect that saw. There's spinning teeth in one end of it!!


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## Brian T. (Dec 19, 2012)

Given the motor rpm and the 10" blades, I worked out that the rim speed is 180mph. While I don't believe that the 2x4 came back at me at that speed, it was fast enough to get my full attention.

What was worse, though, was a TC tooth coming off a 10" blade and drilling me in the forehead.


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## woodnthings (Jan 24, 2009)

*show us your math*

Back when I came up with this:
A table saw blade at 4000 or so RPM with a 10" blade has a peripheral *speed* of 4000 x pi D or 125,600 in per min divided by 12 equals 10,466 ft per min. divided 5280 equals miles per min. times 60 equals 118.93 MPH. FYI

Another site, Lumberjocks, came up with this: 
my saw says it runs at* 5,000 *rpm. It uses a 10” blade.
So, the circumfrence is 31.4” (10×3.14)
So, if it was a wheel, it would be moving at 157,000 inches per minute. (31.4×5,000)
That’s 13,083.33 feet per minute. (157,000 / 12)
Or 785,000 feet per hour. (13,083.33×60)
Which comes out to 148.7 miles per hour. (13,083.33 / 5,280)


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## sawdust703 (Jun 27, 2014)

Seriously woodenthings? Show us your math? The man was just trying to make a point, not impress us w/his mathematical skills. I thought this thread was about table saw safety? You made your point.


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## Brian T. (Dec 19, 2012)

Woodnthings, you need a TC blade tooth embedded in your forehead to comprehend the issue. They are a whole lot bigger than you think. Bring your own bandages.
My saw cranks 5,800rpm, the last time we checked it with the strobo tachy.


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## woodnthings (Jan 24, 2009)

*not questioning your post but*

The 180 MPH was different from what I calculated, so I wanted to know why? The 5,800 RPMs was what made the difference. So, for the fun of it I wanted to know what 180 MPH was in Ft Per Sec, something I can relate to from my knowledge of rifle and handgun ballistics. Turns out to be 264 Ft per sec., about the same as a decent compound bow: http://www.answers.com/Q/What_is_180_mph_in_feet_per_second


Also for reference about the same as a lever action Red Ryder Daisy BB gun:
_The traditional, and still most common powerplant for BB guns is the spring piston, usually patterned after a lever-action rifle or a pump-action shotgun. The lever-action rifle was the first type of BB gun, and still dominates the inexpensive youth BB gun market. The Daisy Model 25, modeled after a pump-action shotgun with a trombone pump-action mechanism, dominated the low-price, higher-performance market for over 50 years. Lever-action models generally have very low velocities, around 84 m/s (275 ft/s), a result of the weak springs used to keep cocking efforts low for use by youths. The Daisy Model 25 typically achieved the highest velocities of its day, ranging from 114 to 145 m/s (375 to 475 ft/s)._[_citation needed_]
https://en.wikipedia.org/wiki/BB_gun

I guess you are lucky to still be alive or still have your vision after that. :yes: As to what you could do to be more safe, which is the topic being discussed ..... nothing that I can think of. :blink:


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## JimGnitecki (Dec 5, 2015)

woodnthings said:


> . . . As to what you could do to be more safe, which is the topic being discussed ..... nothing that I can think of. :blink:


I can think of something: Don't use carbide blades, because they have the potential to have a tooth break off if it hits something hard. On all-steel blades, the teeth are integral to the blade versus being brazed on.

Mind you, as we all know, Carbide blades stay sharper WAY longer and are less likely to be damaged by overheating under heavy load or use of too high a TPI blade for the task at hand . . .

Jim G


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## hwebb99 (Nov 27, 2012)

JimGnitecki said:


> I can think of something: Don't use carbide blades, because they have the potential to have a tooth break off if it hits something hard. On all-steel blades, the teeth are integral to the blade versus being brazed on. Mind you, as we all know, Carbide blades stay sharper WAY longer and are less likely to be damaged by overheating under heavy load or use of too high a TPI blade for the task at hand . . . Jim G


 I can think of something. Don't use a table saw. Problem solved.


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## GeorgeC (Jul 30, 2008)

The circumference of the saw blade is 31.4159 inches. Any point on that circumference travels that distance times 5,800 in a minute or 182,212 in per minute. For one hour that is 182212*60 equals 10,932,720 inches in one hour. Inches in a mile equals 12 times 5286 or 63,432 inches per mile. 10,932,720 divided by 63,432 or 172.3533863034431 mph.

Not that it makes a hill of beans because that velocity is not the speed at which a piece of scrap would be expelled. Too many other variables influence that.

I doubt that there is no one who has ever used a power saw of any type who has not had a piece of scrap thrown at him/her.

George


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## d_slat (Apr 10, 2012)

GeorgeC said:


> Not that it makes a hill of beans because that velocity is not the speed at which a piece of scrap would be expelled.
> 
> George


The scrap, no. But a rogue carbide tooth possibly.


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## JimGnitecki (Dec 5, 2015)

GeorgeC said:


> The circumference of the saw blade is 31.4159 inches. Any point on that circumference travels that distance times 5,800 in a minute or 182,212 in per minute. For one hour that is 182212*60 equals 10,932,720 inches in one hour. Inches in a mile equals 12 times 5286 or 63,432 inches per mile. 10,932,720 divided by 63,432 or 172.3533863034431 mph.
> 
> Not that it makes a hill of beans because that velocity is not the speed at which a piece of scrap would be expelled. Too many other variables influence that.
> 
> ...


You are very close to being correct George, but not exact. There are 5280 feet in a mile, not 5286. The minor error is too small to be concerned about. :smile:

As for ejection speed of a piece of wood or carbide tooth:

- IF the carbide tooth simply becomes detached from the blade, it does get ejected at the 172 mph, because that is the speed it was traveling at in use before its bond with the blade failed. However, if the tooth is ejected as a result of collision with a knot or a nail, the speed will be slower as some of its kinetic energy is unavoidably transmitted to whatever it collided with, and only the remainder gets the carbide piece flying off into air space.

- If a workpiece or cut-off piece of a workpiece is ejected, it is going to be at a far lower speed because a lot of the kinetic energy transmitted by the blade to the wood piece is going to be used up accelerating the wood piece from essentially zero fps to whatever velocity the laws of momentum exchange in a collision will drive it to. In addition, some of the blade energy transmitted to the wood piece gets "used up" tearing nice gouges into the wood. :smile:

Jim G


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## GeorgeC (Jul 30, 2008)

Sometimes a 79 year old memory fails us.

George


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## Brian T. (Dec 19, 2012)

Whatever the Hello the speed was, the TC tooth was going fast enough for me to pick it out of my forehead. The stock was 1/4" Plexiglas.


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## allpurpose (Mar 24, 2016)

I just had to relearn my lesson about leaving scraps on the crosscut sled just moments ago. I left a 3 foot 2X4 on it and before I could think of, well...anything I had that 2X4 flying straight my way. It hit me in the shoulder and I'm ok..It's a little sore, but not as bad as the chunk of finger that made me remember that I have a feather board for a damned good reason..
This could have been much much worse.. Here's one side of the 2X..the other side got a chunk missing as well so it came spinning my way..
Several years ago in a body shop had a chunk of grinding wheel fly back and very nearly ended my sex life..Now that was a tad frightening..It made a believer out of me when it comes to blade guards and handheld high speed grinders..


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## Tony B (Jul 30, 2008)

The few kick-backs that I have had, happened so fast that I never knew where the piece landed unless it hit something along the way - like me, sometimes. Several years back I had a kickback and I searched the shop high and low and could not find the piece. When I shut down at night and went to my van, I saw the piece across the driveway in the mini-storage lot. Apparently, it had hit the unit across the way. It traveled about 50 feet and so fast, I had no idea what direction it went.


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## allpurpose (Mar 24, 2016)

Sounds like me Tony. Wife and I went out to eat and while sitting at the table I noticed a big dried gash on my arm. I had no idea the flying 2X4 hit my arm. My shoulder hurts, but no gash. Arm? Didn't feel it. It looks a whole lot worse than it feels.


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