Workpiece drifts away from fence on table saw

[jeff phillips]

I am having a rough time with my table saw. Frequently when ripping wood, the workpiece wants to drift away from the fence at its rear edge. The saw is a 3hp Sawstop PCS, and there are no alignment issues between the blade and the fence. I even pulled out the alignment gauge this weekend and verified that both the blade and fence are within .001" of alignment with the miter gauge.

I am convinced that it is a technique issue, because if I maintain positive pressure against the fence throughout the cut, there is no issue and I get a clean smooth cut. The trouble comes when the piece is short, or I am near the end of the cut and can no longer maintain leverage on the piece to keep it against the fence, then it frequently tends to start drifting again.

I can't imagine that putting a feather board downstream of the blade is a good idea, so what is the solution?

[Michael Peet]

Jeff, have you checked that the riving knife isn't pulling the piece to the left?

Don't set the featherboard downstream!

Mike

[Clint Baxter]

I'd check to make sure the Irving knife isn't causing the issue. Your saw blade could also be the culprit. Have you tried a different blade to see if the issue happens with more than one blade.

Good luck,

Clint

[George Brown]

On smaller pieces, I use the Gripper which allows me to both push the wood into the blade and also keep it tight against the fence. I don't have any issues that way.

[jeff phillips]

The riving knife is in alignment with the blade. The left side of the riving knife is flush with the left face of the blade.

I have been experiencing this with both a Freud glue line rip blade and a Freud fusion blade.

And just to be clear, I don't need to force the workpiece against the fence, its more of a gentle drift. If I can maintain slight pressure there is no problem, but on the short pieces, and towards the end of the larger ones, I can't seem to maintain that pressure when pushing through the blade.

[G Douglas Fowler]

Did you check the alignment by placing a reliable straightedge against the blade and then measure to the fence/miter track at various points along the top from front to back? If so and the splitter is properly aligned, I second the idea that you may have a defective blade.

[Clint Baxter]

Ideally your riving knife shouldn't contact either side of your wood unless the wood tries to pinch together. If the wood is tight to your riving knife on the side opposite the fence it may be causing your issue a slight adjustment, (if possible), towards the fence might be in order. This is assuming the wood is nt already tight to that side as well.

Clint

[Bob Wingard]

The riving knife should be centered on the kerf ... not adjacent to either side of it. Try a rip with the knife out of the saw ... if it goes away, you've identified the problem. About the only other cause would be a warped fence ... though unlikely.

[joe milana]

Jeff, It could be one of a couple things. The fence is toeing away from the blade slightly (which is ok). The side grind on the two blades you are using forces the sawn wood to follow the cut line & not the fence. I can set my fence by it. Make sure the blade is clean! Another thing is if the wood has tension & the kerf is closing up as cut, the off-cut side will pinch the back side of the blade & cause the wood to pull away from the fence slightly. Oh, and one other thing, Those plywood SS fences are a PIA to get flat. Try taking a jointed board & just run it down the fence. See if there is a high spot in the fence. Also note that that black rubber edging on the fence can cause the edges of the fence to bulge slightly. Best to remove that stuff & trim the fence faces down on the top, front, and back ends.

[mreza Salav]

how short of a piece you are talking about when you say you have this problem on short pieces?
I don't think riving knife can have anything to do with this issue: it can cause pushing things against the fence but not pulling it away from the fence.
I have a feeling you are trying to cut a piece that is too short. Also, where on the front edge of the piece are you pushing?

[Bob Wingard]

I don't think riving knife can have anything to do with this issue: it can cause pushing things against the fence but not pulling it away from the fence.


The riving knife can, and will pull the stock in either direction, depending on how it is misaligned. To the left side of the blade ... pulls away from the fence. Toward the right side of the blade ... pulls towards the fence ... usually feels like it's binding, and hard to move the stock forward.

The knife, not being absolutely rigid, allows you to pull it toward the fence during most of the cut ... but, when you run out of control surface, the piece follows the knife and pulls away. I wouldn't recommend a regular practice of it, but, if you'll remove the riving knife and make a cut, you'll soon know if that is your problem.

[Neil Bosdet]

Hey Jeff, do you have the issue when cutting plywood or mdf? Check if you don't know. I'm wondering if it's tension in the wood your ripping.

Neil

[Rod Sheridan]

I am having a rough time with my table saw. Frequently when ripping wood, the workpiece wants to drift away from the fence at its rear edge. The saw is a 3hp Sawstop PCS, and there are no alignment issues between the blade and the fence. I even pulled out the alignment gauge this weekend and verified that both the blade and fence are within .001" of alignment with the miter gauge.

I am convinced that it is a technique issue, because if I maintain positive pressure against the fence throughout the cut, there is no issue and I get a clean smooth cut. The trouble comes when the piece is short, or I am near the end of the cut and can no longer maintain leverage on the piece to keep it against the fence, then it frequently tends to start drifting again.

I can't imagine that putting a feather board downstream of the blade is a good idea, so what is the solution?

Jeff, it does sound like technique, and I'll illustrate two methods of using a push stick and what can happen.

1) you rip a piece of wood and place the push stick much closer to the fence, than the blade. When you push, the wood will rotate to the left, away from the fence.

2) same setup as above, however your push stick is much closer to the blade than the fence. When you push, the wood will rotate to the right, into the fence.

Using a push block will also allow you to push slightly into the fence, as you push, this keeps the piece tight against the fence.

Regards, Rod.

[Glen Blanchard]

If the problem only occurs on truly short pieces, it may be that you don't have a way to keep continuous pressure against the fence. As previously stated, try "The Gripper". It will easily help you maintain pressure against the fence for the entire cut (which I would think will solve your problem if it is only a technique thing).

[Russ Ambrose]

can't really add anything to the analysis already offered by others as to the cause of your problem, but i'm chiming in to add yet another vote for using a pair of Grippers. since i've begun using them, i've had no issues ripping smaller pieces. plus, they make ripping smaller pieces so much more safe. i also find the Gripper quite useful when cutting down big sheet stock...easy to keep those big pieces riding against the fence through the entire cut

[Bob Wingard]

+1 regarding GRRIPPERS ... I got a pair when they first hit the market and wouldn't want to be without them.

[Erik France]

Peachtree has a special on a gripper package right now: http://www.ptreeusa.com/edirect_041312.htm

I have a pair and use them quite a bit on narrow and small pieces. The 1/8" leg is great for narrow rips.

[Alan Schwabacher]

If your riving knife is centered on the blade, it should push the stock neither to right or left, even if there is fuzz in the kerf. You do need to control the stock all the way through the cut. If the riving knife is aligned to the left edge of the blade, it could push the stock away from the fence sometimes, which would not be desirable, though you could overpower the tendency.

I see no problems with aligning the right edge of the blade with the right edge of the riving knife, where it will help you hold the stock to the fence. This seems reasonable unless you move the fence to the left of the blade.

[jeff phillips]

I think I have it fixed. I opened up the owners manual and took a look at how Sawstop recommends the riving knife be aligned. As I mentioned before, when I first set up the saw, it came from the factory with the riving knife aligned with the left side of the sawplate. The manual actually recommends aligning it with the right side using a straight edge. I went through the setup procedure exactly as described in the manual, and it seems to have fixed the problem.

I had just assumed if it was aligned somewhere behind the blade it was fine, I never considered that where it was aligned behind the blade would make a difference.

Thanks for all the input.

[Mark W Pugh]

Peachtree has a special on a gripper package right now: http://www.ptreeusa.com/edirect_041312.htm

I have a pair and use them quite a bit on narrow and small pieces. The 1/8" leg is great for narrow rips.

Or you can get the set for a fare price. Two works great with longer pieces. http://www.amazon.com/Micro-Jig-gr200-dvd-hbx2-Grr-ripper-Supreme/dp/B003W2DGB8/ref=sr_1_18?ie=UTF8&qid=1334736411&sr=8-18

[Lee Schierer]

You can use a feather board like the one made by Grip-Tite (http://www.grip-tite.com/Site/Home.html) behind the blade. They make a steel fence that attaches to your regular fence that allows the magnets to be used in a vertical orientation. They also sell a Roller Guide kit (http://www.grip-tite.com/Site/Products-and-Prices.html) that fits onto their magnetic feather boards that is specifically designed to hold rip cut pieces tight to the fence. I have these on my saw and have used them extensively. I can attest that the roller does a superb job of holding the stock tight to the fence. At their website there is a video showing the roller guide working on a rip cut. The bias on the roller actually pulls the stock to the fence as you make the cut.

[Rod Sheridan]

Hi Jeff, remeber that if you align the splitter with the edge of the blade, you'll have to re-adjust when you change blades.

My saw manual reccomends aligning it with the center of the saw blade, that way as you change blades it doesn't need adjustment..........Rod.