Getting Straight Table-Saw Rips

Tips on tuning a table saw for straight ripping. May 23, 2007

Question
The problem I’m having is difficulty getting perfectly straight cuts with a tablesaw. I'll rip one side, then turn it to rip the other side and watching the edge of the wood as it travels along the fence, it appears as if my previous cut curves away from the fence. The front and rear end of the board maintain good fence contact, it's just this 1/64" gap that appears in the middle.

The equipment I'm using is Delta unisaw with Unifence and a Freud combination blade.

All saw components appear to be parallel. Generally, the material being cut tends to wander from the fence at the far end unless I really force it into place. I'm cutting plywood and some thin hardwood. Maybe this is a stress release problem rather than a cutting issue?

Forum Responses
(Solid Wood Machining Forum)
From contributor D:
Sometimes a thin kerf blade can cause a problem.

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From contributor D:
You rip one side then turn it to rip the other? If the other side needs ripping then it was not straight to begin with as far as the lumber goes. Joint the edge first. If the plywood is doing it then it might be the blade but more likely it is how you feed the stock.

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From contributor T:
When you say that all saw parts are parallel, does that mean you have checked them with an indicator? The thing that bothers me is that you say that the outfeed side of your wood wanders away from the fence. This would indicate to me that the blade is not parallel with the fence. The forward edge of your blade may be to the right of the trailing edge of the blade. The cupping of your material could be caused by your attempts to keep the material against the fence at both ends.

The proper way to check the straightness of your saw parts is by mounting a dial indicator on the mitre gauge of your saw. Then position the point of the indicator on the plate of a fully raised saw blade. Slide the indicator along the plate and read the difference between the front of the blade and the back. Make adjustments until the front and back of the blade indicate the same. After your blade is set parallel to the mitre slot, then do the same for your fence. Also, Contributor H is correct about thin kerf saws. If the blade is very thin and you are not running stabilizer collars you can have problems with blade deflection.