# What caused my kickback?



## JoeKan (Apr 25, 2015)

I was ripping 1 x 12 x 10s today and the first time I did it, my board stopped halfway through the cut. I don't know why unless it was hitting on my riving knife? Anyway, I took it out and turn it over and thought I could finish the cut by going the other way. I got it cut to almost where the first cut had stopped and then it kicked back. Smacked me in the stomach but only startled me.
What did I do wrong?
BTW, first time I've used a table saw. I did read up on it throughly. 
Thanks,
Joe


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## JoeKan (Apr 25, 2015)

Never mind, cancel that, I had a major brain glitch. 
Sorry for the bother.


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## Steve Neul (Sep 2, 2011)

It's hard to say without having being there. More than likely the board closed up behind the blade pinching the blade or the riving knife. This happens a lot on pine and there is nothing you can do about it but shut the saw off and pry the board off the blade. 

How much HP is your saw. Normally with a 3hp saw or smaller you can bring the saw to a stop before it would actually kick you.


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## woodchux (Jul 6, 2014)

Glad you did not get hurt, and solved the reason for the "kick-back". Care to share "what happened" for some of us that are new to TS wood cutting issues? Be safe.


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## firehawkmph (Apr 26, 2008)

Joe,
Don't stand directly behind the wood you're feeding through the table saw. I always stay out of the line of fire. A lot of times boards have internal tension that is released upon cutting, causing the pinching.
Mike Hawkins


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## woodnthings (Jan 24, 2009)

*table saw physics....*



JoeKan said:


> I was ripping 1 x 12 x 10s today and the first time I did it, my board stopped halfway through the cut. I don't know why unless it was hitting on my riving knife? Anyway, I took it out and turn it over and thought I could finish the cut by going the other way. I got it cut to almost where the first cut had stopped and then it kicked back. Smacked me in the stomach but only startled me.
> What did I do wrong?
> BTW, first time I've used a table saw. I did read up on it throughly.
> Thanks,
> Joe


Here's what happens on a table saw when ripping.
The table is a flat horizontal plane as is the workpiece, or it should be straight and flat. :yes:

The blade, riving knife or splitter and fence are vertical planes at 90 degrees to the table, but parallel to each other.

If anything is out of adjustment, like the fence is not parallel to the blade, or the work isn't flat on the table, or the work comes off the fence at the rear, it will bind against the blade and either stall the motor or kickback.

The other cause of a kickback is the wood itself closes on the back of the blade, pinching it and it will ride up on the rotating blade and over the top and kickback.
So the advice not to stand directly in the blade path is good, but are times that it's not possible and you have to just maintain a good registration to the fence and make your cut.

Table saws are the greatest tool, but there is a learning curve, so use all your safety equipment, especially a splitter or riving knife and use only straight and flat wood on the table. 

The workpiece's straight edge always is against the fence so it can't wiggle or move, another cause of a kickback. Best if you can joint the boards before sawing them on the table saw. If not, sight down them to see how straight they are and don't use any with bumps or curves that will cause a kickback!

:smile:


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## Rebelwork (Jan 15, 2012)

firehawkmph said:


> Joe,
> Don't stand directly behind the wood you're feeding through the table saw. I always stay out of the line of fire. A lot of times boards have internal tension that is released upon cutting, causing the pinching.
> Mike Hawkins


Here we go again:no:


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## JSmithKC (Jun 21, 2015)

*Re:*

Always inspect the edge of your stock.....









(A) is correct.:thumbsup:
(B) is dangerous:thumbdown:


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## FrankC (Aug 24, 2012)

JSmithKC said:


> Always inspect the edge of your stock.....
> 
> View attachment 168818
> 
> ...


I would not run a bowed board either way without a carrier to run against the fence.
http://benchnotes.com/Taper and Straight Edge Jig/taper_and_straight_edge_ji.htm


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## woodnthings (Jan 24, 2009)

*Absolutely!*



FrankC said:


> I would not run a bowed board either way without a carrier to run against the fence.
> http://benchnotes.com/Taper and Straight Edge Jig/taper_and_straight_edge_ji.htm



You are essentially cutting freehand if the bowed side is against the fence. If the cupped/curved side is against the fence you'll run out of fence and the far end will swing inwards and bind the blade causing a kickback.
NEITHER way is "correct" or safe. 
A board carrier or a straight line jig is the best and safest way to deal with boards that are not straight on the fence. :yes:


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## Chamfer (Sep 6, 2014)

I'm with Mike on at least that one safety point.

I've had several kickbacks where the material became a missal and shot straight back and only one binding where it went over the top of the blade, but never been hit by any of them. The only situation I can think of putting you in the line of fire is ripping large sheet goods but I don't use the TS for that.

Not standing behind the material will at a minimum save you some bruises (or much worse) while you're in the 'learning curve'.


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## k9scooter (Mar 5, 2014)

Have you checked your fence for negative angle of feed? I always adjust mine for some runout in the rear of the fence.


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## mikeswoods (May 18, 2009)

Experience teaches a lot---your ears are a great safety tool---the saw cutting sound will change before the board binds and kicks back---learn the sound of the tool operating smoothly--and be alert when the sound changes----


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## Toolman2 (Jun 15, 2010)

mikeswoods said:


> Experience teaches a lot---your ears are a great safety tool---the saw cutting sound will change before the board binds and kicks back---learn the sound of the tool operating smoothly--and be alert when the sound changes----


This is so true. Last week I was ripping several 2x6 boards, both pine and Austrian Spruce. Although both species look the same and are about the same weight, the density of the spruce is a lot more because of the tighter growth rings (I'm assuming). Anyway, when ripping the spruce on some of the boards, the saw starts to bog down no matter the feed rate, even after trying to run them through the opposite way. I solved the problem by ripping them with the thinner width against the fence instead of the thicker width. But the sound of the saw tells all when ripping.:thumbsup:


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## woodnthings (Jan 24, 2009)

Toolman2 said:


> ..... I solved the problem by ripping them with the thinner width against the fence instead of the thicker width. But the sound of the saw tells all when ripping.:thumbsup:


This tells me that the fence is slightly out of parallel with the blade. The wood and amount of wood being cut is the same no matter which direction you feed it or which way it lays on the saw, off fall in or off fall out. It should make no difference.

Is there a splitter on the saw?

Which rip blade did you use? thin kerf? full kerf? How many teeth? :blink:


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## Oneal-Woodworking (Apr 14, 2013)

k9scooter said:


> Have you checked your fence for negative angle of feed? I always adjust mine for some runout in the rear of the fence.


 
I have absolutely NO idea what you are talking about. Perhaps someone can explain this one to me and explain why this is a 'good thing'. 

Fence should be true to the blade at all times in my opinion. Otherwise you are asking for an accident or causing stresses on your blade and material that do not 'need' to be there.


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## Toolman2 (Jun 15, 2010)

woodnthings said:


> This tells me that the fence is slightly out of parallel with the blade. The wood and amount of wood being cut is the same no matter which direction you feed it or which way it lays on the saw, off fall in or off fall out. It should make no difference.
> 
> Is there a splitter on the saw?
> 
> Which rip blade did you use? thin kerf? full kerf? How many teeth? :blink:


The saw has a splitter and I'm using a new, 24 tooth, thin kerf ripping blade. I did go check and it's parallel.


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## woodnthings (Jan 24, 2009)

*Then I suspect ....*



Toolman2 said:


> The saw has a splitter and I'm using a new, 24 tooth, thin kerf ripping blade. I did go check and it's parallel.


Possibly, the side of the board you were cutting initially, had a curve to it and as you progressed the dimension between the blade and the fence changed slightly causing it to bind and bog down. There is just not much else that would cause that issue that I can think of.


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## FrankC (Aug 24, 2012)

OnealWoodworking said:


> I have absolutely NO idea what you are talking about. Perhaps someone can explain this one to me and explain why this is a 'good thing'.
> 
> Fence should be true to the blade at all times in my opinion. Otherwise you are asking for an accident or causing stresses on your blade and material that do not 'need' to be there.


It is not uncommon for some to kick the rear of the fence out a bit, if it is out 1/32 overall it is only out about 1/64 at the blade.


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## Rebelwork (Jan 15, 2012)

FrankC said:


> It is not uncommon for some to kick the rear of the fence out a bit, if it is out 1/32 overall it is only out about 1/64 at the blade.


It's an common problem as well...


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## FrankC (Aug 24, 2012)

Rebelwork said:


> It's an common problem as well...


Actually that seems to be a matter of opinion.

The argument is unless you have a fence that can be moved and always lock perfectly parallel to the blade then give it a little clearance at the far end so there is less chance of it being toed in and causing problems.

Im not advocating it, just the messenger.


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## k9scooter (Mar 5, 2014)

The first cut I made on my new Powermatic 64 had a bad kickback...
I used a dial caliper to adjust the rear of my fence so that it was about 5000's wider as the wood went thru the fence.
The only other problems I ever had was with wood that had internal stresses; mostly exotic hardwoods..


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## Toolman2 (Jun 15, 2010)

woodnthings said:


> Possibly, the side of the board you were cutting initially, had a curve to it and as you progressed the dimension between the blade and the fence changed slightly causing it to bind and bog down. There is just not much else that would cause that issue that I can think of.


That would have been the case, but I initially trimmed about 1/4"" off the outsides of each board before hand since I was going to glue them up in the end.

This weekend, I'll double check the saw's alignment again and clean the innerds and lube it up just to make sure, thanks.:thumbsup:


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## Rebelwork (Jan 15, 2012)

FrankC said:


> Actually that seems to be a matter of opinion.
> 
> The argument is unless you have a fence that can be moved and always lock perfectly parallel to the blade then give it a little clearance at the far end so there is less chance of it being toed in and causing problems.
> 
> Im not advocating it, just the messenger.


Not an opinion, fact. I catch a guy pivoting my saw he's looking for new employment tomorrow.


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## woodnthings (Jan 24, 2009)

*what do you mean....*



Rebelwork said:


> Not an opinion, fact. I catch a guy *pivoting my saw *he's looking for new employment tomorrow.



What does that mean, the saw, the fence?
Where is your fence set? Out of parallel with the slots? Toed out at the rear? 

Mine is always set parallel to the slots and to the blade.

A few thousands at the rear will do you no real good if the board moves 1/16" at the rear. A splitter is what I have come to rely on after years of not really understanding what they do. It keeps the kerf open and the work against the fence. IF the wood moves away at the kerf, it will bind against the fence and probably stall the motor, kinda rare but it has happened. JMO.


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## FrankC (Aug 24, 2012)

Rebelwork said:


> Not an opinion, fact. I catch a guy pivoting my saw he's looking for new employment tomorrow.


With that attitude it is the best thing that could happen to him, not an opinion, fact!


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## Rebelwork (Jan 15, 2012)

I think if you feel you need to pivot the fence to feel more secure by all means do so. But I'm not putting a 100 guys behind the saw trying to keep plywood and lumber against the fence knowing the blades "not" parallel with the fence. There's no + or - on the fence only "0".


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## FrankC (Aug 24, 2012)

That "0" is there at the spot you measure and set it, on most saws once the fence is moved all bets are off, particularly with a "T" style fence running against a square tube that is not machined to be perfectly accurate. So yes, some do like to have a bit of leeway just to prevent any possibility of toein. 
As I said this is one opinion and since this is a discussion board I have posted it as such for those with open minds to consider.


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## Rebelwork (Jan 15, 2012)

FrankC said:


> That "0" is there at the spot you measure and set it, on most saws once the fence is moved all bets are off, particularly with a "T" style fence running against a square tube that is not machined to be perfectly accurate. So yes, some do like to have a bit of leeway just to prevent any possibility of toein.
> As I said this is one opinion and since this is a discussion board I have posted it as such for those with open minds to consider.


An open mind can be a good thing sometimes but not when setting a fence. If you take a biesemeyer fence for instance. the fence locks in the front. If your cutting plywood at 8' your already putting pressure on the back of the fence keeping it taunt to the fence and probably causing a + on the back end. Why would anybody want to create a + to start with?

Secondly...After you move the fence all bets are off? Sounds like its time for you to get a new saw or atleast a good working saw fence that stays parallel to the blade...


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## Rebelwork (Jan 15, 2012)

Here's a question for you. How you going to run a scoring blade on a saw to get melamine not to chip on the bottom side on a + fence setup?


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## FrankC (Aug 24, 2012)

I have a good fence and I know how to feed material through it without putting enough pressure on the back end to force it out of alignment.

I have also built enough equipment to know the tolerances that steel tubing meets, close enough for woodworking but don't give me this absolute "0" nonsense along the length of it.


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## FrankC (Aug 24, 2012)

Rebelwork said:


> Here's a question for you. How you going to run a scoring blade on a saw to get melamine not to chip on the bottom side on a + fence setup?


Your "0" "+" and "-" settings do not exist except on precision machines generally made for machining metal. Woodworking tools are made to standards that are good enough to get the job done and therefore allowances have to be made.

Setting a fence the thickness of two sheets of paper wider at the far end will not cause your melamine to chip.


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## Rebelwork (Jan 15, 2012)

FrankC said:


> Your "0" "+" and "-" settings do not exist except on precision machines generally made for machining metal. Woodworking tools are made to standards that are good enough to get the job done and therefore allowances have to be made.
> 
> Setting a fence the thickness of two sheets of paper wider at the far end will not cause your melamine to chip.


Sorry but I can't sell "good enough" in my business. I have to work with higher tolerances than "good enough"


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## woodnthings (Jan 24, 2009)

*we've gone from kickback to scoring blades*

A machine with a scoring blade probably has a sliding table and is about 8 ft long and cost over 20K. A home shop table saw and fence is not in the same league, so comparisons won't apply. Apples and bananas...

https://www.youtube.com/watch?v=MT8Yo4GGv2E


There's also another "theory" on table saw fences, beside the kicked out at the rear theory, the short fence. I'm not a fan of this either, but there's You Tuber who swears by it to prevent kickback:

https://www.youtube.com/watch?v=d7QXIN2X8-w


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## Rebelwork (Jan 15, 2012)

woodnthings said:


> A machine with a scoring blade probably has a sliding table and is about 8 ft long and cost over 20K. A home shop table saw and fence is not in the same league, so comparisons won't apply. Apples and bananas...
> 
> https://www.youtube.com/watch?v=MT8Yo4GGv2E
> 
> ...


You'll use the fence with a slider just like a table saw when making rips...Apples to Apples


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## Oneal-Woodworking (Apr 14, 2013)

Rebelwork said:


> An open mind can be a good thing sometimes but not when setting a fence. If you take a biesemeyer fence for instance. the fence locks in the front. If your cutting plywood at 8' your already putting pressure on the back of the fence keeping it taunt to the fence and probably causing a + on the back end. Why would anybody want to create a + to start with?
> 
> *Secondly...After you move the fence all bets are off? Sounds like its time for you to get a new saw or atleast a good working saw fence that stays parallel to the blade*...


Agree with everything you said. Especially the part in bold. :yes:


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## woodnthings (Jan 24, 2009)

*I disagree*

When ripping an 8 ft length of plywood you can't really apply pressure at the back of the fence because the saw cut or kerf is behind the blade. Your pressure should always be toward the fence in front of the blade and forward simultaneously, at least that's how I do it. 

If you are jacking the whole panel around trying to maintain registration against the fence as you make the pass, either you haven't adequate side and rear support, OR you don't know how to operate the saw. 

Both my Beisemeyer fences are rock solid and won't budge at the rear under normal operation, at least in my shop. My other 2 Delta Unifences are just as solid when locked down. I like each type fence for different reasons.

You have two choices when making a dimensioned cut. Measure from the tip of the blade to the fence or use the tape measure that's on the fence rail. It doesn't matter which method you use as long as you are consistent. I like to make a cut on a scrap, measure it as precisely as possible, then set my indicator on the tape to that dimension. Then make another pass and check it for accuracy in a different location on the tape.


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## Rebelwork (Jan 15, 2012)

If that board or panel isn't on the fence in the back as it would be in the front I can only imagine its gonna be in your hip sooner or later. There's no if, what or but to this problem except poor management of their saw. 

By the way... You can push a fence out in the back if one tries to.


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## woodnthings (Jan 24, 2009)

Rebelwork said:


> By the way... You can push a fence out in the back if one tries to.



You are correct. I can hook my John Deere to it and give it a tug, but that would not be "normal operation" now would it? The Biese isn't the most popular and heaviest and most copied and imitated fence because it's a piece of crap. It's because it strong, reliable and works well and resets to parallel when locked.... at least in my experience.


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