Safety at Your Table

[dusty]

It is my belief that Kickback is the direct result of one of two conditions. The two conditions being 1) the kerf closing on the blade or 2) the material being cut riding up on the teeth of the blade on the outfeed side.

If this is true, using a splitter and featherboard at the outfeed side of the blade would greatly reduce the likelyhood of kickback.

Please participate in the accompanying poll to indicate your concurrence or disagreement with this theory. If you have real strong feelings about this, please comment in a post to this thread.

I am working on a modification to my splitter that will allow the simultaneous use of a featherboard on the outfeed side of the blade. The one obstacle that I have encountered is that I cannot do non through cuts with my concept.

One major short coming is that I would not be using the upper saw guard but I could have the anti kickback pawls(with a very slight design change).

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[JPG]

I agree with the poll statement, but would not agree that that is ALWAYS the case.

RE a non-through cut: Are you referring to a shallow cut that does not penetrate the top surface of the workpiece, or a cut that does not go all the way to the back end of the workpiece? Obviously the former cannot make use of the riving knife. The second one could be done by shutting the saw off when the cut has gone as far as desired. However that method increases the risk of kickback and depending upon what you are 'adding' may require some 'disassembly'.

[heathicus]

It is my belief that Kickback is the direct result of one of two conditions. The two conditions being 1) the kerf closing on the blade or 2) the material being cut riding up on the teeth of the blade on the outfeed side.

While I'm still a newb and by no means an expert, I would agree. Couldn't it also be caused by the material being lifted off of the table in front of the blade as well?

If this is true, using a splitter and featherboard at the outfeed side of the blade would greatly reduce the likelyhood of kickback.

So you mean a featherboard above the material holding the material down against the table correct?

I am working on a modification to my splitter that will allow the simultaneous use of a featherboard on the outfeed side of the blade. The one obstacle that I have encountered is that I cannot do non through cuts with my concept.

One major short coming is that I would not be using the upper saw guard but I could have the anti kickback pawls(with a very slight design change).

(Photo Image to be Added here)

But you don't need a splitter with non-through cuts, correct? The remaining material works to keep the kerf from closing on the blade. So at issue is really the featherboard.

Isn't it conventional wisdom that a featherboard holding the material down on the table is best placed just before the material reached the blade, not at its exit? That seems to me to be the safest place for it. With the featherboard in front of the blade, the material would be prevented from raising from the table until it cleared the front of the blade. With the featherboard behind the blade, unless you had an outfeed table, that could still allow a pivot point that would let the material lift up from the table.

I would think the safest combination would be anti-kickback prawls behind the blade and a featherboard in front of the blade. Am I wrong?

[dusty]

JPG: No, I was not referring to a cut that does not penetrate thru the top surface of the material being cut (Example: dado). Nor was I referring to a cut where the material needs to be dropped down onto the spinning blade (like a bling dado).

Heathicus: I suppose you might be correct but on the input side the blade tends to force the material onto the table. Some hazards might still exist but not typically kickback (unless caused by the blade being squeezed).

All hell breaks loose when the material is lifted off the table on the outfeed side allowing the material to travel up onto the top of the blade. At this point, the material is catapulted back into your gut or upward into your face. Great pain occurs either way.

I have no argument at all for your last statement. Kickback pawls and properly installed feather board do the job almost all of the time. But they have to be used to work.

All to often, we take these devices off for convenience sake or forget to install them because we are in a rush to get something done.

I am trying to develop something that, because of its physical nature is never in the way (for standard rip cuts or cross cuts). Example and Confession: I often do not use the upper saw guard when cross cutting. Don't ask me to defend that, I can't. But it is the truth.

[charlese]

I think I have a problem with your idea of a featherboard behind the saw blade.

As pictured in your post, the featherboard would serve as an additional vertical hold down, but it would also serve as an impediment for the cutoff to travel SAFELY past the spinning saw blade. This impediment could lead to other problems such as the piece getting inadvertently bumped or twisted to cause it to be thrown by the blade. We want both the workpiece and the cutoff to easily and safely pass completely by the saw blade, without any restriction.

The rear featherboard would also be a serious impediment to a cross cut operation. As we have all learned - some the hard way - it is not safe to withdraw a crosscut back past a spinning blade. Too many things are possible to cause the board, or the cutoff to get thrown or mis-cut by a spinning blade. The only safe operation includes a crosscut pass completely past the blade. The rear featherboard would stop a cutoff before it clears the blade causing an immediate safety issue.

Actually, we all knew you didn't use the upper saw guard for cross cuts. The anti kick-back pawls would prevent withdrawing a crosscut back past the spinning blade.

[joedw00]

All to often, we take these devices off for convenience sake or forget to install them because we are in a rush to get something done.
Example and Confession: I often do not use the upper saw guard when cross cutting. Don't ask me to defend that, I can't. But it is the truth.

I won't ask you to defend that, because I put the saw guard on when I was setting up my Shopsmith. After a few cuts I took it off, and never reinstalled it. It just seems to be in the way. I'm sure that if I used it I would get used to it.

[JPG]

I won't ask you to defend that, because I put the saw guard on when I was setting up my Shopsmith. After a few cuts I took it off, and never reinstalled it. It just seems to be in the way. I'm sure that if I used it I would get used to it.

And some folks never got one with their new ss(it was an extra cost extra).

[dusty]

I won't ask you to defend that, because I put the saw guard on when I was setting up my Shopsmith. After a few cuts I took it off, and never reinstalled it. It just seems to be in the way. I'm sure that if I used it I would get used to it.

If you are interested in parting with it, send me a PM.

BUT, if you don't use it, please consider trying this first. Remove the plastic blade guard completely. It is easy to remove and just as easy to put back. With it removed, you are left with a riving knife equipped with kick back pawls.

[dusty]

I think I have a problem with your idea of a featherboard behind the saw blade.

As pictured in your post, the featherboard would serve as an additional vertical hold down, but it would also serve as an impediment for the cutoff to travel SAFELY past the spinning saw blade. This impediment could lead to other problems such as the piece getting inadvertently bumped or twisted to cause it to be thrown by the blade. We want both the workpiece and the cutoff to easily and safely pass completely by the saw blade, without any restriction.

The rear featherboard would also be a serious impediment to a cross cut operation. As we have all learned - some the hard way - it is not safe to withdraw a crosscut back past a spinning blade. Too many things are possible to cause the board, or the cutoff to get thrown or mis-cut by a spinning blade. The only safe operation includes a crosscut pass completely past the blade. The rear featherboard would stop a cutoff before it clears the blade causing an immediate safety issue.

Actually, we all knew you didn't use the upper saw guard for cross cuts. The anti kick-back pawls would prevent withdrawing a crosscut back past the spinning blade.

I think you might be absolutely correct about the position of the featherboard that is on the left side of the blade. That featherboard, if used at all, should be moved further toward the back of the table.

As far as dragging the stock back, the existence of this featherboard would greatly reduce that. It would force that the stock should be pulled away from the blade before being drawn back.

Thank you, Charlese for your comments.

[robinson46176]

It is my belief that Kickback is the direct result of one of two conditions. The two conditions being 1) the kerf closing on the blade or 2) the material being cut riding up on the teeth of the blade on the outfeed side.
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I believe that almost all kickbacks are the direct result of the operator not being in charge of the board being cut... In all of my about 50 years of sawing on a table saw (sometimes a little, sometimes a lot) I have just never had a problem with kickback. I almost never use a guard and only occasionally a splitter. I think that some of my lack of a problem is due to inherited traits from my 7th great uncle, King Kong. So far when I grab hold of a board to cut it, I have a hold on the board. I am very heavy and very strong. That may come back to bite me as I grow older and lose strength.
I really like the feather board mounted to the fence and a second one behind the blade would be fine but I see no reason to have one on the opposite side of the blade from the fence on what I would normally consider the waste piece. It can not bind between a fence and the blade and there is no reason it should ever kick back. I see no problem from it being there though. I do often use a feather board on the table to hold a board over against the fence but only in front of the blade of course. You never want to be pushing the board over behind the blade as that might pinch it against the blade.
I am constantly amazed at how many cuts I see being made (mostly on TV) where the board has lifted a quarter to a half inch off of the table at the back. A second feather board would help that a lot. A set of "Board Buddies" could also help there.
I would not mind adding one of those splitters to my main table saw (not a SS) that are plastic and slip in and out just behind the blade.
Another thing that I believe gets folks in trouble is this mentality that hand tools are to be avoided at all cost. I see huge elaborate efforts made so that a tiny cut that could be cut in 60 seconds with a good hand tool can be cut with all kinds of effort on a table saw after a 20 minute setup and $30 of jig building. Now if you are making 20 such cuts that is another matter. The point is if a piece is so small that you cannot get hold of it well it becomes a likely kickback risk.
The main thing that everybody should do is keep looking at and thinking about what you are doing with a fresh look all of the time and especially so when safety is involved which is exactly what Dusty is doing right now. Sometimes we become too comfortable with our bad habits.