# Violent kickbacks when cutting trim miters on tablesaw



## Sawdust2012 (Sep 17, 2013)

For some reason when I try to cut a 45 in a piece of maple beading, the cutoff gets kicked back. This has happened a few times today, and if I hadn't been standing to the side, would have been serious. I'm sure this is a technique issue. Can anyone help?


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## Kazooman (Jan 20, 2013)

Rather than a picture of the work piece, how about a picture of your setup and a description of what you do.

Are you using a miter gauge? A sled? Tilting the blade to 45 or is it at 90 with the work piece at the angle?

Too many possibilities to venture a guess without more information.


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## Sawdust2012 (Sep 17, 2013)

Good point, K-zoo. I'm using an incra fence and shop stop with their v-27 gauge. The picture is how I have it set up.









No clue why the pics are posting upside down


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## MrUnix (May 18, 2012)

> No clue why the pics are posting upside down
> - Sawdust2012


I'm guessing it's because you took the photo with your phone and you were holding it in the wrong orientation.. sure does make my neck hurt trying to look at it upside down though - so here is a PSA for the rest of the crowd:










Cheers,
Brad

PS: The "Preview" button will let you see the posing before you submit it - so it gives you a chance to fix stuff like the above before committing to it. Just saying


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## Kazooman (Jan 20, 2013)

It looks like the rounded part of the beading is down on the table. My guess is that without a flat surface on the table the cutoff is rolling on the curve and somehow contacting the blade. If that is the case you could either flip the work piece so the flat is on the bottom (that would require you to set up the cut differently) or perhaps clamp a piece of stock to what will be the cutoff so that it will not roll. The latter would only work if the cutoff piece was long enough for this to work.


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## Loren (May 30, 2008)

Tiny cutoffs frequently fly off. I use a guard,
protection and stand out of the way.

Blade height may be a factor. I haven't given
it much though though.


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## Sawdust2012 (Sep 17, 2013)

I never thought about the rounded edge causing that, but it just about has to be that. Thanks!


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## Kazooman (Jan 20, 2013)

After I posted I thought about it some more. I think that if the cut off rotated back towards the front of the saw it would be fine, but on the occasion that it rolled forward then the top edge would definitely hit the blade.

Perhaps suit up in hockey goalie gear?


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## John Smith_inFL (Dec 15, 2017)

kick-backs can be caused from a number of reasons - all of which could lead to catastrophic injuries !!!
standing to the side of the direct line of fire is a good habit to get into.
believe-you-me, a chunk of wood in the face is no picnic !!!!

do you have a full table-sized sled for your table saw ?

.


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## Sawdust2012 (Sep 17, 2013)

I never have made one. I'ts one of those things they always seemed too complicated and I was hoping to avoid that with the incra system. I have a feeling I am wrong


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## ArtMann (Mar 1, 2016)

Before I built a sled, I used an Incra fence to cut thousands of miters and I still do for angles other than 45. I have never had the kind of trouble you are describing. There is something else going on here. Perhaps your blade isn't aligned very well with the miter slot? Is the kickback occurring after the wood has gone past the down traveling teeth and is contacting the up traveling teeth? Could it be that you don't have good tight control of the wood as it passes over the blade? There are many potential root causes.

I agree with John that you really need to build crosscut and miter sleds, even though it will be a lot of trouble to get them dead accurate. There are a lot of instructions on how to do this on the internet and especially Youtube. You can also buy commercially built sleds and some of them have adjustable angles. I don't think they are as good as a good shop built one though.


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## clin (Sep 3, 2015)

Another vote for the rounded side being down as being the main culprit here. As Loren said, small cutoffs are prone to this. I think becasue they are more easily affected by the last bit of cutting and can more easily move due to their light weight.

But with that rounded off side down, the cutoff cannot stand on its own and is going to move and I think whether it falls forward or back, the angle cut ensures it will rotate into the blade.

I don't think this was mentioned, but another idea would be to put on a wooden extension to the fence. Something that would allow you to clamp the cutoff to the fence. And of course being a wooden extension you can cut right through it. Obviously this extension needs to be tall enough it remains whole after you cut part way through it.

And I know John knows what he's talking about when it comes to kickbacks. He definitely got my attention with his story and photos of his accident.


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## bondogaposis (Dec 18, 2011)

Are the cutoff wedges getting in the gap in the insert? If so a zero clearance insert will fix it.


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## John Smith_inFL (Dec 15, 2017)

a closer look at the arrangement.










.


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## Ripper70 (Nov 30, 2015)

> Are the cutoff wedges getting in the gap in the insert? If so a zero clearance insert will fix it.
> 
> - bondogaposis


+1 Especially if the small chunks of wood are angled. It'll be easier for them to try to wedge themselves into the space between and become little projectiles. I've had the blade create enough air movement to pick small pieces up just enough to drop them back on the spinning blade where they then shoot off in a totally random direction.

Maybe a full face shield may be a worthwhile investment.


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## Kazooman (Jan 20, 2013)

Good comments on the insert slot, but take another look at the first picture the OP posted. I doubt that a piece that size got in the slot.

I think I got the rotations reversed in my second comment. Based on the angle shown in the picture, a piece rotating back towards the front of the saw would strike the blade.


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## JackDuren (Oct 10, 2015)

Usually kickbacks on a miter come from vibration. The part not being secured correctly.


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## Sawdust2012 (Sep 17, 2013)

Wow! This is why I appreciate LJ so deeply! I'm going to declare the mystery solved by Kazooman with his curvy side down pickup. I took some steps to ameliorate that and the problem was solved. John Smith takes the award for "most persuasive", and if anyone wants to post plans of a miter sled simple enough for someone who CAN screw it up, I'm absolutely on the look out!


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## JackDuren (Oct 10, 2015)

curvy side down doesn't matter… I use the Incra often…


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## Sawdust2012 (Sep 17, 2013)

Yuh huh…does too!


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## Ted78 (Dec 3, 2012)

Curve side down probably doesn't help but like a previous poster said, any little cutoff piece can easily fall or blow or vibrate into the front of the blade once it's separated from the rest of the stock and shoot back. If it's happening consistently then do something different, but don't get complacent.


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## Ripper70 (Nov 30, 2015)

> ...and if anyone wants to post plans of a miter sled simple enough for someone who CAN screw it up, I'm absolutely on the look out!
> 
> - Sawdust2012


Check YouTube. There are dozens of designs in all shapes and sizes. Some for 45 degree cuts and some that are adjustable. Some very complex some very simple.


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## Loren (May 30, 2008)

I don't recommend letting cutoffs sit there
and chatter near the side of the blade. I
flick them away with a stick.


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## wormil (Nov 19, 2011)

Kickback happens when wood pinches the back of the blade. If the wood is clamped securely, that round edge is irrelevant. My guess is you were using the fence as a stop block or the clamp was loose and allowing the piece to vibrate and rotate into the blade or twist. Turning the piece around will make it more secure but the underlying cause is not being clamped securely or the cutoff being pinched.


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## John Smith_inFL (Dec 15, 2017)

spend an hour or so in the evenings perusing Pinterest to find a sled
that is within your skill set and you will be sooooooo glad you did !!

=table%7Cautocomplete%7Cundefined&term_meta[]=saw%7Cautocomplete%7Cundefined&term_meta[]=sled%7Cautocomplete%7Cundefined]https://www.pinterest.com/search/pins/?rs=ac&len=2&q=table%20saw%20sled&eq=table%20saw&etslf=NaN&term_meta[]=table%7Cautocomplete%7Cundefined&term_meta[]=saw%7Cautocomplete%7Cundefined&term_meta[]=sled%7Cautocomplete%7Cundefined

the first sled I made, I forgot to shim the sides of the runners and it had maybe 
a 1/16" wiggle in it but it worked for simple crosscutting. (I did fix the wiggle - it's tight now).
I am making two more out of 3/4" birch plywood now that will have recessed T-Track for hold-downs and jigs.
after you make one - you will want to make more !!!!

.


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## Kazooman (Jan 20, 2013)

Hi John:

I agree that sleds are the way to go. However, I am not certain that many sleds would solve the OP's problem. I have MANY sleds and one I built t for 45 degree miters might fit the bill. It has two fences set at a 45 degree angle to the blade. The offending off cut would be turned away from the blade by the other fence.


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## Kazooman (Jan 20, 2013)

> Kickback happens when wood pinches the back of the blade. If the wood is clamped securely, that round edge is irrelevant. My guess is you were using the fence as a stop block or the clamp was loose and allowing the piece to vibrate and rotate into the blade or twist. Turning the piece around will make it more secure but the underlying cause is not being clamped securely or the cutoff being pinched.
> 
> - Rick_M


Sorry, but none of that makes any sense. We are discussing what happens to the off cut after it leaves the blade. There is NO clamping at that point. What happens to the off cut piece is up to the laws of gravity. Several suggested clamping the cut off as a solution.

What do you mean by using the "fence as a stop block"? Using a miter gauge or dedicated sled with a "stop block" to create a desired length piece is common practice. How does that create a kickback problem

Just confused.


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## wormil (Nov 19, 2011)

The off cut pictured has two cut marks, meaning it was sawn, then sawn again. The cut marks are deep, not surface cuts, so they didn't just vibrate into the blade, it was pushed into the blade. If the pieces were just laying around until they vibrated into the blade he would have seen the obvious problem and there would be diagonal imprints from the teeth. So somehow the piece was rolling as it was cut or twisting or pinched between the blade and fence.


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## alittleoff (Nov 27, 2014)

Another vote for the round edge and the hard maple wood. I had the same thing happen to me a few days ago. Not a kickback but it ripped the wood from my hand while using a miter saw. I tried it again an it did the same thing. The wood that i was cutting was trim for a clock face and had a round edge. After the second try igave up an was going to try it on the table saw, using a incra miter Gage. So much for that. I think when it cuts through the thick part and part way through the thinner piece the maple woop breaks causing it to kickback. JMO
Gerald


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## Carloz (Oct 12, 2016)

Why dont you just tilt the blade for this kind of cut?


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## Carloz (Oct 12, 2016)

> Kickback happens when wood pinches the back of the blade. If the wood is clamped securely, that round edge is irrelevant. My guess is you were using the fence as a stop block or the clamp was loose and allowing the piece to vibrate and rotate into the blade or twist. Turning the piece around will make it more secure but the underlying cause is not being clamped securely or the cutoff being pinched.
> 
> - Rick_M
> 
> ...


You get confused so easily. Any stop on the right of the blade whether it is the fence or a stop on the sled has a potential of kickback,


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## Kazooman (Jan 20, 2013)

Ah, I understand what you were saying. I thought you were referring to a stop on the fence of his incra miter gauge to determine the length of the piece. That is a common practice. You are correct that using the main table saw fence to the right will lead to pinching of the cut off. There is no indication that the OP did that. The fence is not even in the picture he provided of the setup. He stated that the problem went away when he corrected the curved side down issue. Even a square piece of stock would have problems if he was using the fence as a stop.


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## Sawdust2012 (Sep 17, 2013)

Just for the sake of my reputation, I am NOT using the rip fence while making cross cuts. Carloz brings up a good point about tilting the blade to make the cut. I have had trouble with blade deflection doing that on a miter saw in the past, but it would have to be a safer cut due to a larger surface area in contact with the tablesaw. In this situation, it was the rounded edge allowing the cutoff, long or short, to rotate into the leading teeth. It makes a loud pop as the piece is pushed against the table and propelled out much like a golfing iron forces the ball against the ground and out… right towards water.


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## Carloz (Oct 12, 2016)

In any case this was a useful post. Round bottom or not, if the cutoff is tall it can fall on the blade.


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## RichT (Oct 14, 2016)

> You get confused so easily. Any stop on the right of the blade whether it is the fence or a stop on the sled has a potential of kickback,
> 
> - Carloz


You clearly do not know how to set up a stop block.


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## wormil (Nov 19, 2011)

May also benefit from waxing the table. Even if the clamp was loose, the piece shouldn't have rotated into the blade



> Ah, I understand what you were saying. I thought you were referring to a stop on the fence of his incra miter gauge to determine the length of the piece. That is a common practice. You are correct that using the main table saw fence to the right will lead to pinching of the cut off. There is no indication that the OP did that. The fence is not even in the picture he provided of the setup. He stated that the problem went away when he corrected the curved side down issue. Even a square piece of stock would have problems if he was using the fence as a stop.
> 
> - Kazooman


Thing is, round side down shouldn't make any difference if the piece is clamped. Yes, it will be less stable but it's riding on the fence. Something was binding or causing the piece to twist or rotate. The piece shown also has two cut marks which makes me wonder if it wasn't catching.


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## wormil (Nov 19, 2011)

> You get confused so easily. Any stop on the right of the blade whether it is the fence or a stop on the sled has a potential of kickback,
> 
> - Carloz
> 
> ...


He's explaining my post, I'm the one that brought up a fence. Good practice is to clamp a block to the fence so pieces don't get trapped between fence and blade, but not everyone knows that. I've cut plenty of rounded stock without a sled, it doesn't kickback.


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## Kazooman (Jan 20, 2013)

> May also benefit from waxing the table. Even if the clamp was loose, the piece shouldn t have rotated into the blade
> 
> Thing is, round side down shouldn t make any difference if the piece is clamped. Yes, it will be less stable but it s riding on the fence. Something was binding or causing the piece to twist or rotate. The piece shown also has two cut marks which makes me wonder if it wasn t catching.
> 
> - Rick_M


You do understand that it is the cut off that was thrown, not the piece that was clamped to the fence. The cut off wasn't clamped to anything.


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## wormil (Nov 19, 2011)

> You do understand that it is the cut off that was thrown, not the piece that was clamped to the fence. The cut off wasn't clamped to anything.
> - Kazooman


At that angle and with a rounded bottom, the pieces are going to fall away from the blade, not into it. Try it. And the saw must have a lot of vibration to move a piece that size into the blade hard enough to throw it back.

Here's a crude drawing of how the offcut will land. I don't think it would be thrown back unless it was rotating or twisting into the blade.


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## builtinbkyn (Oct 29, 2015)

I started to post last night how it would have been better to keep the miter gauge at 90' to the blade and simply tilt the blade to the required angle, but the phone rang and the post never happened. What I find odd about the setup is the clamp on the workpiece. There's no need for it and in fact, that could be the source of the issue. I have the same Incra miter gauge and it's not very clamp friendly. The profile of the gauge is designed specifically for their proprietary stop. It also appears from the pic that the rubber on the jaws are touching the table. That's probably not a good idea as they could just possibly hang up on something, causing the clamping pressure to release a bit.

With the blade set high enough and the OP simply holding the workpiece rather than clamping it, I don't see how a kickback could occur, even with the rounded edge to the table.


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## Kazooman (Jan 20, 2013)

> You do understand that it is the cut off that was thrown, not the piece that was clamped to the fence. The cut off wasn't clamped to anything.
> - Kazooman
> 
> At that angle and with a rounded bottom, the pieces are going to fall away from the blade, not into it. Try it. And the saw must have a lot of vibration to move a piece that size into the blade hard enough to throw it back.
> ...


I am not going to try it, since I do not care to get injured. The OP has tried it and he has told everyone that he had repeated kickbacks of the off cut piece when the rounded portion was on the table. Changing that practice so the rounded edge was not down cured the problem. That seems pretty definitive to me. No need for me to do any experimentation. I believe the OP.

Regarding your drawing. The small off cut piece you show is resting on the rounded face which is at a 45 degree angle to the blade. All things being equal it could roll forward away from the blade or roll backwards hitting the teeth and subsequently launching across the shop. However, all things are not equal. That piece was just cut off by a rapidly rotating saw blade that was pushing it backwards. Any friction between the blade and the off cut is going to cause it to roll backwards and into the blade. The OP has found this to be the case.


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## Kazooman (Jan 20, 2013)

> With the blade set high enough and the OP simply holding the workpiece rather than clamping it, I don t see how a kickback could occur, even with the rounded edge to the table.
> 
> - builtinbkyn


I don't understand all of the focus on how the work piece was attached to the incra miter gauge. From all that the OP has told us nothing went wrong on that side of the blade. I assume that his work piece survived its trip past the blade just fine. It is what happened on the other side of the blade that is at issue. That is, what happened to the off cut piece. I don't see how hand holding the stock to the incra gauge or clamping it to the gauge or attaching it with super glue would have any meaningful effect on the off cut.


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## wormil (Nov 19, 2011)

It's not a dowel, it isn't going to roll on the table, it's going to fall over. I believe the entire piece was binding as it was cut. If your explanation were correct, flipping it over would have made no difference and it would still be getting thrown.


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## Sawdust2012 (Sep 17, 2013)

You are right, kazoo. It was the offcut. No problems whatsoever on the piece held to the fence! Call it fate, Bernoulli effect, voodoo hex or whatever sounds right, but the offcut was falling into the blade, and being fired out, a feat declared impossible earlier. Later I am going to post a rough drawing of the dead horse we are all continue to beat.


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## builtinbkyn (Oct 29, 2015)

Read my post again. The workpiece may appear to have been securely clamped, but in fact may not have been or the clamp didn't entirely hold well enough thru the cut, that it allowed movement as it passed by the blade. From the OPs latest response, it sounds like that's exactly what was happening. There's no way for the offcut to get pinched unless the workpiece somehow rotated.

However, even if that weren't the case, the clamp is entirely unnecessary and dangerous as the operator has no control over the workpiece without being directly engaged with it. A few fingers over the miter gauge fence is all that's needed. Fingers would not be too close to the blade for comfort. Also IMO spring clamps and saws don't go together well. Positive clamping pressure is needed with a blade spinning at 3500+ rpms. This issue was induced by the user.


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## Kazooman (Jan 20, 2013)

> You are right, kazoo. It was the offcut. No problems whatsoever on the piece held to the fence! Call it fate, Bernoulli effect, voodoo hex or whatever sounds right, but the offcut was falling into the blade, and being fired out, a feat declared impossible earlier. Later I am going to post a rough drawing of the dead horse we are all continue to beat.
> 
> - Sawdust2012


Yep, I have given my last whuppin' to the poor beast.

Geez, I said that and then posted two more replies. Facts remain rounded side down gives kick backs. Flat down does not. I don't imagine that you were careless about holding the work piece when the rounded side was down.

Glad you got the problem solved.


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## Kazooman (Jan 20, 2013)

> It s not a dowel, it isn t going to roll on the table, it s going to fall over. I believe the entire piece was binding as it was cut. If your explanation were correct, flipping it over would have made no difference and it would still be getting thrown.
> 
> - Rick_M


By "roll" I mean that it will be pivoting around the axis of the rounded edge. Of course it will stop when the flat face hits the table. No one ever said that it would roll over, and over, and over like a dowel. Actually, it would not even roll enough to stop on the flat face because it hit the blade first and was thrown at the OP.

It certainly would matter to flip the piece over so that the flat edge was down. That way the off cut would simply sit there like they usually do when making such cuts. It would be stable on the flat face. The off cut was NOT stable on the rounded edge and it fell into the blade and was thrown. Even if the piece only fell in that direction a part of the time, it would still be unacceptably dangerous. The OP proved this without a doubt.

Case closed as far as I am concerned.


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## Kazooman (Jan 20, 2013)

> There s no way for the offcut to get pinched unless the workpiece somehow rotated.
> 
> - builtinbkyn


The off cut was not pinched. After the cut was complete the off cut piece was unstable on the rounded surface. It fell back into the rotating blade. I know that most kick backs are caused by the piece being pinched into the rear of the blade. However, try tossing a small piece of wood into the front teeth on a rotating saw blade. It will go flying. That is just what the OP observed.


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## builtinbkyn (Oct 29, 2015)

I know this is a dead horse, but how does the piece fall back and hit the front teeth if the blade is elevated to the correct height above the workpiece and the small piece is already past the front teeth once it separates from the workpiece?

If I were to make those cuts, I would use a miter saw (manual or powered) with a backup fence. I would use a backup fence on the setup he used, and in fact I do just that with the Incra miter gauge. I actually think the design is terrible without a backup fence to prevent tearout. However I would also never rely on a spring clamp to ensure the piece passing the blade is secure and doesn't move during the cut. I believe it did just that and then pinched the small piece agains the blade. But as I stated, it's my opinion the process was not done correctly or in a safe manner and the results prove it.


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## RichT (Oct 14, 2016)

This is like one of those Friday Open Threads…lol. Everyone is going their own direction.

Kazooman nailed it in post #4, Sawdust2012 acknowledged Kazooman's assessment was correct, and it's just gone on and on from there.


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## Sawdust2012 (Sep 17, 2013)

This is beginning to sound like my custody fight. All that's missing is someone I hate arguing with me at the rate of $350 / hr!


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## wormil (Nov 19, 2011)

> - Sawdust2012


Did the 2 kerf cuts have anything to do with anything? It was brought up a few times and you never responded.

If the piece was somehow rolling backward into the blade, there will be telltale marks on the offcut.


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## DustyM (May 16, 2016)

> This is beginning to sound like my custody fight. All that's missing is someone I hate arguing with me at the rate of $350 / hr!
> 
> - Sawdust2012


Sold! Where do I send the invoice?


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## RichT (Oct 14, 2016)

> This is beginning to sound like my custody fight. All that's missing is someone I hate arguing with me at the rate of $350 / hr!
> 
> - Sawdust2012


Ha ha. Two things never to skimp on - good tools and a good lawyer.


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## Ted78 (Dec 3, 2012)

I"ve got an old no-name rusty 1940's 8" tilting TABLE, fixed arbor saw I'll trade you for your saw, only cut angles so that the cutoff falls right to the floor and away from the blade and Viola!. I'll even throw in the 1/4 HP motor and a nice stiff cracked rubber v-belt.


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## Sawdust2012 (Sep 17, 2013)

Ted…I try to live by the adage, if a deal seems too good to be true, it probably is!


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## wormil (Nov 19, 2011)

> Ted…I try to live by the adage, if a deal seems too good to be true, it probably is!
> 
> - Sawdust2012


So I guess I'm never going to get an answer about the kerfs?


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## Tony_S (Dec 16, 2009)

> This is like one of those Friday Open Threads…lol. Everyone is going their own direction.
> 
> Kazooman nailed it in post #4, Sawdust2012 acknowledged Kazooman s assessment was correct, and it s just gone on and on from there.
> 
> - Rich


I don't think 3/4 of the people responding even had a grasp on what the actual problem was to begin with before they started rambling, and I think some still don't.


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## wormil (Nov 19, 2011)

> I don t think 3/4 of the people responding even had a grasp on what the actual problem was to begin with before they started rambling, and I think some still don t.
> 
> - Tony_S


We agree on that.


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## Smitty_Cabinetshop (Mar 26, 2011)




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