Kickback when ripping at 45 Degrees on table saw.

[Bill Dindner]

I have been woodworking for a long time now, and I can figure out whats going on with this issue.

I am using a Sawstop PCS and get excellent results, but when I am ripping stock at 45 degrees, if the off-cut is small, it almost always gets thrown back pretty hard. I always try and stand to the right of the fence if I can, but is there something that I am doing to cause this?

[Rod Sheridan]

Hi Bill, are the anti-kickback pawls pushing the piece against the blade? Or perhaps the guard?

Since it's a left tilt saw it shouldn't have that issue...........Regards, Rod.

[Bill Dindner]

Hi Bill, are the anti-kickback pawls pushing the piece against the blade? Or perhaps the guard?

Since it's a left tilt saw it shouldn't have that issue...........Regards, Rod.


I don't use a guard, just a riving knife.

Can't figure out whats going on, did not have this issue on my previous table saw

[Martin Wasner]

I have been woodworking for a long time now, and I can figure out whats going on with this issue.

I am using a Sawstop PCS and get excellent results, but when I am ripping stock at 45 degrees, if the off-cut is small, it almost always gets thrown back pretty hard. I always try and stand to the right of the fence if I can, but is there something that I am doing to cause this?


Sometimes it happens. Sometimes it doesn't.

We bevel cut all of our faceframes to paneled ends. We make that cut quite a bit.

Sometimes it happens. Sometimes it doesn't.

I can't tell you who done what to which to cause or prevent it. I'm off to the left of the saw as much as possible when doing things like that. If it comes winging out, then it doesn't matter. If I were to guess, it's just tension being released and a little bit of vacuum being create by the blade pulling it in.

[Peter Christensen]

I don't use a guard, just a riving knife.

Can't figure out whats going on, did not have this issue on my previous table saw


Try with the guard on and see if it still happens.

[Warren Lake]

there is more tension release on a 45 degree than a 90 cut. Machining a 45 compared to ripping it has less tension release

[Charlie Velasquez]

I have been woodworking for a long time now, and I can figure out whats going on with this issue.

I am using a Sawstop PCS and get excellent results, but when I am ripping stock at 45 degrees, if the off-cut is small, it almost always gets thrown back pretty hard. I always try and stand to the right of the fence if I can, but is there something that I am doing to cause this?

Use a stand-off fence. The cut-off will fall harmlessly under the fence.
Edit: this assumes you are just beveling the edge to 45* or whatever

[Lee Schierer]

If you are trapping the cut off between the blade and the fence you will almost always get the piece flying back at you when you finish the cut. Try making your cut so the cut off piece is free to fall away from the blade by putting your work piece against the fence.

[Ben Rivel]

Is it possible the rear of the fence is just a hair closer to the blade than the front and its only showing up with a very light cut off and its kicking back? Have you use a tool like this: LINK (https://www.woodpeck.com/sawgauge.html#1316) to ensure the fence is perfectly flat and parallel to the miter rail?

[Bill Dindner]

Use a stand-off fence. The cut-off will fall harmlessly under the fence.
Edit: this assumes you are just beveling the edge to 45* or whatever

Not sure what a stand off fence is, sometimes I am beveling, sometimes taking more off depends on the cut.


If you are trapping the cut off between the blade and the fence you will almost always get the piece flying back at you when you finish the cut. Try making your cut so the cut off piece is free to fall away from the blade by putting your work piece against the fence.

The Sawstop PCS is a left tilt saw, not really an issue with this design, that would be a problem on a right tilt saw, or if I moved the fence to the right side.


Is it possible the rear of the fence is just a hair closer to the blade than the front and its only showing up with a very light cut off and its kicking back? Have you use a tool like this: LINK (https://www.woodpeck.com/sawgauge.html#1316) to ensure the fence is perfectly flat and parallel to the miter rail?

I own that specific item, the fence is pretty much perfectly parallel to the miter slot, but even if it wasn't, why would that make the off cut kick back exclusively while ripping with a bevel cut?

[Martin Wasner]

If you are trapping the cut off between the blade and the fence you will almost always get the piece flying back at you when you finish the cut. Try by making your cut so the cut off piece is free to fall away from the blade by putting your work piece against the fence.

Aren't all of those saws left tilt? I was just assuming the drop was on the left of the blade and out in the open.

[Andrew Hughes]

Is the cut good or does it have a burning at the beginning or end of the cut. The top might need to be shimmed in the front or back.

[Bill Dindner]

Use a stand-off fence. The cut-off will fall harmlessly under the fence.
Edit: this assumes you are just beveling the edge to 45* or whatever


If you are trapping the cut off between the blade and the fence you will almost always get the piece flying back at you when you finish the cut. Try making your cut so the cut off piece is free to fall away from the blade by putting your work piece against the fence.


Is it possible the rear of the fence is just a hair closer to the blade than the front and its only showing up with a very light cut off and its kicking back? Have you use a tool like this: LINK (https://www.woodpeck.com/sawgauge.html#1316) to ensure the fence is perfectly flat and parallel to the miter rail?


Aren't all of those saws left tilt? I was just assuming the drop was on the left of the blade and out in the open.

You are correct, I don't the he realized the type of saw.


Is the cut good or does it have a burning at the beginning or end of the cut. The top might need to be shimmed in the front or back.


the off cuts look pretty good, the "top" of what needs to be shimmed?

[Simon MacGowen]

I am using a Sawstop PCS and get excellent results, but when I am ripping stock at 45 degrees, if the off-cut is small, it almost always gets thrown back pretty

Check that your sawtable is not tilted to the right on an uneven floor. Vibration will cause the small off-cuts to "inch" towards the blade/fence if the sawtable is lower on the right hand side.

Use the blade guard with the anti-kickback pawl (which may catch the off-cuts)...not just the riving knife, whenever possible.

Simon

[Bill Dindner]

Use a stand-off fence. The cut-off will fall harmlessly under the fence.
Edit: this assumes you are just beveling the edge to 45* or whatever


If you are trapping the cut off between the blade and the fence you will almost always get the piece flying back at you when you finish the cut. Try making your cut so the cut off piece is free to fall away from the blade by putting your work piece against the fence.


Is it possible the rear of the fence is just a hair closer to the blade than the front and its only showing up with a very light cut off and its kicking back? Have you use a tool like this: LINK (https://www.woodpeck.com/sawgauge.html#1316) to ensure the fence is perfectly flat and parallel to the miter rail?


Aren't all of those saws left tilt? I was just assuming the drop was on the left of the blade and out in the open.


Is the cut good or does it have a burning at the beginning or end of the cut. The top might need to be shimmed in the front or back.


Check that your sawtable is not tilted to the right on an uneven floor. Vibration will cause the small off-cuts to "inch" towards the blade/fence if the sawtable is lower on the right hand side.

Use the blade guard with the anti-kickback pawl (which may catch the off-cuts)...not just the riving knife, whenever possible.

Simon


I guess the anti kick back pawl will do something if the cutoff is a bit bigger than the bevel, but I don't think they will make contact on a simple bevel.

[Simon MacGowen]

The pawl is 3/4" from the riving knife of the guard on the PCS. If the waste side (off-cut) is an inch wide or more, the pawl should function as designed. Did you get a chance look into the leveling factor of the saw? My tablesaw tilts slightly on the left (2 to 3 degrees or so due to the floor). I measured the last few bevel off-cuts left in the shop and they are about 1/4" to 1/2" wide by 14 to 16" long.

Release of tension shouldn't be a factor in your case as they were off-cuts on the left side of the blade.

Simon

[Jacob Reverb]

The Sawstop PCS is a left tilt saw, not really an issue with this design, that would be a problem on a right tilt saw, or if I moved the fence to the right side.

On my left-tilt saw, if I was going to rip something on a 45, I think I would put the fence on the right of the blade with the workpiece between fence and blade, with offcut "free."

It sounds like you're putting the fence on the left of the blade and ripping that way? Seems like that would make the blade want to pull the workpiece away from the fence, and allow the offcut to fall (due to gravity) against the spinning blade once it was detached from the workpiece. Could that be why the offcut wants to kick back?

I don't think I've ever used the fence on the left side of the blade on my left-tilt saw. Not that I consciously thought about it, but it never occurred to me why I might want to do that, I guess.

[Bill Dindner]

Check that your sawtable is not tilted to the right on an uneven floor. Vibration will cause the small off-cuts to "inch" towards the blade/fence if the sawtable is lower on the right hand side.

Use the blade guard with the anti-kickback pawl (which may catch the off-cuts)...not just the riving knife, whenever possible.

Simon

ill check, however the kickback generally occurs right after I complete the cut, but I’ll check later.

[Simon MacGowen]

Did he actually mean the fence was on the right side of the blade as it is a left-tilt saw when he cut the bevel (so he cut-off was on the left side of the blade)?. It is not a safe practice to cut a stock pinched between a blade angled towards the fence.

Simon

[Charles Lent]

Can you post a picture showing the position of your fence, the piece about to be cut, and if you are using the miter gauge, please show it in it's position and setting? Sometimes it's easier to see the problem in a picture than to try to describe it.

Charley

[Nick Shattuck]

How long are the boards? Does the kickback correlate with the length of the cut?

[Bill Dindner]

Can you post a picture showing the position of your fence, the piece about to be cut, and if you are using the miter gauge, please show it in it's position and setting? Sometimes it's easier to see the problem in a picture than to try to describe it.

Charley

I'll try and take a pic tomorrow


How long are the boards? Does the kickback correlate with the length of the cut?

Happens more often on shorter cuts, something less than 3ft


ill check, however the kickback generally occurs right after I complete the cut, but I’ll check later.


The table bed does lean a hair to the right, perhaps that the issue, may try a shim

[Jim Morgan]

A table saw that is perfectly aligned when the blade is square to the table can nevertheless be misaligned when the blade is tilted 45°. As a thought experiment, imagine tilting the blade a full 90°. If the blade is not parallel to the table - in particular if the table is higher in the back - as you pass your board through the cut it will bind at the back of the blade and kick back. When the blade is square to the table, any front-to-back tilt is irrelevant (and left-right tilt within reason is easily compensated for by setting the 90° and 45° stops). As soon as you begin to tilt the blade, the front-to-back table tilt comes into play, increasingly so as the blade tilt is increased. To cure your problem, shim the front of the table up a bit.

[Bill Dufour]

Gravity. depending on blade tilt will either cause the offcut to fall into the blade or to fall away. A 90 degree piece will fall straight down since the cut line is not sloped. Took me years to figure this out. Depending on the friction of the wood surfaces the scrap may stick well enough to not fall into the blade
Bill D.

[Bill Dindner]

A table saw that is perfectly aligned when the blade is square to the table can nevertheless be misaligned when the blade is tilted 45°. As a thought experiment, imagine tilting the blade a full 90°. If the blade is not parallel to the table - in particular if the table is higher in the back - as you pass your board through the cut it will bind at the back of the blade and kick back. When the blade is square to the table, any front-to-back tilt is irrelevant (and left-right tilt within reason is easily compensated for by setting the 90° and 45° stops). As soon as you begin to tilt the blade, the front-to-back table tilt comes into play, increasingly so as the blade tilt is increased. To cure your problem, shim the front of the table up a bit.

That’s not something I had considered, and it makes allot of sense. I’ll try and see if I can shim the table


Gravity. depending on blade tilt will either cause the offcut to fall into the blade or to fall away. A 90 degree piece will fall straight down since the cut line is not sloped. Took me years to figure this out. Depending on the friction of the wood surfaces the scrap may stick well enough to not fall into the blade
Bill D.


Interesting, makes sense, although here it’s not so much falling as sucked back right away and shot back.

[William Hodge]

To prevent beveled edge rippings from shooting, I bevel edges with a dado blade. The waste ends up as chips in the dust collector, not a Flying Missile of Future Impalement. If I'm feeling lazy, and in a hurry for just one piece (normally a prelude to a story of Gore) I set the cut wide,and bevel 3/16" at a time, making a few cuts. There is no stick to fly, just feathers.

[glenn bradley]

Here's my guess . . . Assuming good blade alignment at 45 degrees (mine was great right out of the box and I'm a picky so-and-so) I wonder if the stock is being fully supported after the cut. If you are ripping something, say 30" or so, there is plenty of the cutoff to hang off the end of the saw thereby tilting the part still on the saw table up and into the blade. If the keeper and the spoil fully supported by an outfeed table or other method to keep it on the same plane as the table?

[Bill Dufour]

Don't forget the blade is moving about 60MPH so it has a fan action which can suck or blow wood around until it touches the blade and then gets flung.
Bill

[Peter Christensen]

Can always mount a vacuum cleaner hose a few inches from the side and it will suck the off cut away from the blade.

[Joe Kaufman]

The 45 deg alignment on my PCS was off as received. The rear of the blade was cutting on the upward rotation. I attempted to align the blade to the tilt axis per the procedure in the manual, pg67-69. I made the condition worse so tried to reverse the adjustments. I would be interested if anyone has successfully completed that procedure.

[Bill White]

Have you called SawStop?

[johnny means]

This happens because the front of the blade is trying to drag the off cut with it. Think about how during a 90 degree cut the front of the blade is pushing the piece downwards. Tilt the blade and now it's pulling the end of your off cut down and to the right. This in turn wedges the piece in tighter, which increases friction, thus pulling the piece in the direction of the blades rotation. You ever seen a pitching machine, same principle. I use a flat push block that I use as a follower to push the good piece and the off cut about an inch or two past the front of the blade. At this point the downward arc of the blade is less pronounced. I then back my push block out and clear my saw.

[Tim Bueler]

We moved a couple years ago. Whatever happened, the first time I tried a 45* bevel cut on my PM-66 I was having difficulties. Since it worked perfectly before we moved the saw somehow got damaged in the move. I was coming up with burn marks on one side or the other of the cut and the accompanying fling of the offcut. Even though I was calibrated for parallel, etc., at 90* it didn't translate to staying parallel at 45*. What I ended up doing was shimming the back of the table so it was coplaner with the saw blade at full tilt. Haven't had any problems since.

[Joe Kaufman]

Did not contact SawStop. The alignment process is well defined, but pretty convoluted with several warnings. I discovered shortly after attempting the process that the miter slot was tight at the front for about the first 1.5 inches. I have asked 8-10 PCS owners if they checked the 45 degree alignment. None have or noted any problems.

[mark mcfarlane]

Both under table and overhead dust collection can suck lighter offcuts into the blade. Reducing suction in this situation may help.

[William Hodge]

Here's a photo of my saw cutting a bevel with a dado blade. Note there is no scrap stick to kick back.395652

[Lee Schierer]

Bill how high is you blade raised above the surface of the pieces you are ripping? The higher you set the blade above the work piece the more down force the teeth exert on the cut and the less horizontal force is exerted on the cut off piece.

Is your riving knife the proper thickness for the blade you are using? Is it properly aligned with the blade?

[Bill Dindner]

Bill how high is you blade raised above the surface of the pieces you are ripping? The higher you set the blade above the work piece the more down force the teeth exert on the cut and the less horizontal force is exerted on the cut off piece.

Is your riving knife the proper thickness for the blade you are using? Is it properly aligned with the blade?

Blade height is usually as low as I can go, the riving knife is the stock one that came with the saw and I use a full kerf blade, don't know if it's aligned, but I have no issues with 90 Degree cuts.