Tablesaw Question

[Thomas Mitchell]

Here's something I noticed last night and thought maybe someone could provide a cause. I was running close to 1" walnut through the tablesaw. As soon as the blade finished the cut, no noise came from the blade, meaning, as I finished the pass between the blade and the fence, the blade did not touch the wood. I cut some 1 1/2" pine, basically a 2x4 milled down to the right dimension, and as I finished the cut, the blade was making contact with the wood several times. The pine was 2 - 3 times longer than the walnut. Both were edged on a jointer with that edge against the fence.

I checked and the blade is perpendicular to the sawtop as is the fence.

Any ideas why the blade hit the pine but not the walnut?

Thomas

[Leon]

It could be your technique, but more likely the longer pine board was not truly straight although it had just come from the jointer. This is all assuming that you made no adjustments to blade height and or fence location.

[Thomas Mitchell]

I bet that I did adjust the blade height. I always check height and adjust the blade to the proper height for the thickness of the wood. I'm certain that I changed the fence position as well. I use an incra TSIIIa system so the fence should be parallel with the blade at all times, but I haven't had it long enough to know that from experience.

Thomas

Le> It could be your technique, but more likely the longer pine board was not

[Leon]

Well, the fence is most likely not the problem....I had envisioned a sears model. If there is wear on the trunion there could be some shift in blade angle relative to the fence as you raise or lower the blade... Are you using a thin kerf blade by any chance? I could be deflecting in the thicker stock.

[Justin]

My guess would be that you freed up some internal stresses in the pine when you reduced it's width, which made it bow against the blade. What's the grain like on the pine, are both the walnut and the pine quartersawn ? I'd assume that the pine is younger than the walnut (i.e plantation grown), therefore the grain isn't as tight as the walnut and more prone to movement over both the short and long term.

Then again the simple answer could be that owing to it's length, any side to side deviation from you guiding the pine through the final stages of the rip is amplified 2-3 times more than the walnut...................

HTH,

Justin.

[Preston Andreas]

If everything is set up properly and the board is straight, most likely, the wood is moving as it is being cut. This is common in pine or improperly dried wood. I have had the kerf close enough to stop the sawblade. Or, it curves against the fence, pushing the stock into the blade. I have also had the end of the board curl up 10"-12" up in the air.

[George]

Look at the grade stamp for one clue. It probably says "S-Dry" on it. Means a quick and dirty kiln trip to get the surface dry enough to plane. No allowances made for the interior. So you have a partially case-hardened piece of lumber, in the case of a 2x4, normally cut close to the heart where the grain is as its most random, and your blade is heating the sides of the cut as it moves through.

I wonder why every board doesn't act squirrelly.