Tablesaw blade alignment problem

[Greg Woloshyn]

I have a Delta contractors saw and I'm having a problem with getting the blade aligned correctly to the fence. When I'm ripping a piece as soon as it gets to the other side of the blade (end of cut) the back teeth cut into it. I used my dial indicator in the miter slot to ensure my blade was aligned to the slot which it was, and so was the fence! Both appear to be aligned within a few thousandths. The freud blade is fairly new and clean and runs true. What else am I missing?

[Paul K. Johnson]

I have a DeWalt contractor saw and the rack and pinion for the fence had weird play. If I moved the fence out then the front of the fence would be farther from the blade than the back of the fence. If I moved the fence in then the front of the fence would be closer to the blade.

I finally adjusted the blade to be parallel when moving the fence in so any time I needed to move the fence out I moved it too much and then back in to the final setting.

You might have a similar issue where the fence aligns differently depending on whether you're moving it in or moving it out.

[glenn bradley]

Paul may be on to something. You say the blade and fence both align to the miter slot. I assume you have rigged something up to slide in the miter slot while an indicator rides the fence. This same rig could be used to touch the same spot on the blade with that spot rotated forward or back. Once all that checks out, position the rig to check the fence, slide the fence a foot or so to the right and then return it within measuring distance, lock it down and re-check. Are things still good?

[Andrew Hughes]

Check to see if the fence is flat.If it curves inward at the end you might have to adjust it out more.

[Lee Schierer]

It sounds like you have a fence clamping issue. Many OEM fences don't always clamp down square on the table. I had that problem for years before I switched to a Beismeyer fence. I've had no issues since.

[Greg Woloshyn]

Thanks everyone for the help, I'll be checking the fence out tonight and see what I have. The did check the fence to make sure it is flat and square.

[Greg Woloshyn]

Well, I tried everything suggested here and still cannot solve the problem. I used my indicator to verify blade alignment to miter slot using the same spot rotated front to back (checked within .002) and the fence is also within that spec, rechecked in different spots.

I hate to move my fence outward away from the blade if it checks parallel to everything else just to try and correct the problem..

Here is a video where you can see towards the end of the cut wood chips fly up indicating the back teeth are cutting..

https://youtu.be/ZHdaphYZcmo

[lee cox]

If it checks to .002 out I don't see how this could happen. You probably need to check the blade on all the teeth. The other thing I would do is run your indicator up and down the miter slot and check the whole length of your fence. I think something has to be out more than .002 to cause your problem. I guess one other thing is you could be pushing the board crooked to cause a bind.

I have never seen a fence .002 out. I worked on my fence for a while and ended up using European Baltic birch plywood to get it to .005 out on the full length of the fence on my Unisaw. It was the best I could do. My blade is .002 or less out.

[Paul K. Johnson]

OK, I see several ways this could happen. If the board is bowed even a little then if the concave side is against the fence then the board exiting the blade will contact the rear teeth in most cases.

The blade could be warped or have some problem with the teeth.

The arbor bearings may have a problem that only show up under load.

Have you tried a different blade?

[Greg Woloshyn]

The boards are jointed square before I use them so I know they are running straight. I tried two different blades and got the same result - so it can't be the blade.

When I pull on the arbor with the blade off, the bearings feel tight and sound fine - but there is some noticeable play in the pinion gears for adjusting up and down, and left to right. Gears should have some clearance though. I'm wondering if this is causing the blade to move around in the cut.

[Doug Garson]

I notice you don't have splitter or riving knife and it doesn't look like it in your video but is it possible when you push the wood thru you aren't keeping pressure against the fence and the wood is moving slightly away from the fence? Try adding a shop made splitter to prevent this.

[Bill Space]

As Doug said, perhaps it is a technique issue.

I have been following this thread and wondered what I might do I do if I had the same problem.

Do you have a thickness planer? If not then what I am about to suggest has no value…

I have a planner so what I would do is first joint a piece of wood and come up with a straight edge, and then I would pass it through my thickness planer on edge, so that I had a piece of wood that had two parallel sides.

Since you believe the back end of the blade is cutting the wood, that means that the back end of the blade is closer to the fence than the front end of the blade.

I would pick one edge of the board and put a lot of pencil marks on it. I would then adjust the fence so that the front edge of the blade was just missing that side of the wood. In other words, the front of the blade would not cut the wood, but the wood would pass very close to the blade teeth.

I might push the wood halfway through the blade just to verify that the front of the blade was not cutting the wood.

After verifying that the front half of the blade was not cutting the wood, I would push the wood all the way through, past the blade, and take a look at the pencil marks, and see what was removed and what was not.

If it turned out that all the pencil marks were removed, then I would conclude that the fence was tilted in towards the blade at the far end.

If The pencil marks were only removed from the back of the test piece, then I might conclude that my technique was at fault.

If none of the pencil marks were removed I would repeat after moving the fence slightly closer to the blade until I had some definitive information.

Just what I would do to zero in on the problem. Ymmv 😀.

Bill

[Chris Parks]

Slightly toeing out the fence should fix this as well as being a safety measure against kickback. Where the idea of having the fence absolutely parallel ever came from beats me as it is the saw blade that guides the wood after the cut is started. I know that is an heretical idea around here but when some though is given to it that is what happens for most of what we cut.

[Greg Woloshyn]

Sure, I can try to correct it by adjusting the fence and blade out of parallel to the miter slots, but I shouldn't have to and it doesn't seem like the right fix. I've been loosing the blade mount underneath and tapping it in to get it parallel to the miter slot where it should be.

[Chris Parks]

I will repeat what I posted above and even add to that, the fence SHOULD toe out slightly and not be parallel if only for safety reasons and nothing else. No European saw has a fence that extends past the leading edge of the blade because it is not needed and is in fact dangerous. Can anyone tell me what is the big deal with a parallel full length fence is?