Wobbly Saw Blade

[wdelliott]

My plywood saw blade was wobbly recently on a cut. I'm not sure why. All the settings and fittings were tight and straight. Yet, when cutting plywood, that plywood blade wobbled.

Any thoughts?

[algale]

Was the arbor set screw hitting the flat of the quill?

[dusty]

My plywood saw blade was wobbly recently on a cut. I'm not sure why. All the settings and fittings were tight and straight. Yet, when cutting plywood, that plywood blade wobbled.

Any thoughts?

If you have another blade, mount it and check for wobble. If it does not wobble, the other arbor or blade are suspect.

Do you have individual arbors for each bad? I highly recommend that.

Remove the wobbly blade and make sure that it and the arbor are clean. Remount the blade and retest.

If you still have noticeable wobble, you may have a bent blade.

How significant is the wobble? You can quantify that by measuring the width of the cut. A wobbly blade will act just like a wobble dado blade. The kerf will be wider than expected.

[JPG]

Did you let it get too hot? If the periphery gets hotter than the center, the expanded metal goes sideways.

[wdelliott]

Thanks everyone. I doubled check all fittings, set screws, etc. Everything was tight and straight. Excessive heat might be the answer, though I had the impression that the blade itself was weak.I was cutting some high-grade plywood and a lot of it. Perhaps the blade became hot and hence weakened.

The blade was wandering off the line.

Once finished, and after power was off, I used my hand to try to force a wobble and could not succeed.

My other SS blades did not experience this problem.

I probably should just purchase another plywood blade and be done with it.

Thanks for all the input.

[rcplaneguy]

I've had dull blades wander due to poor cutting efficiency, closed kerf, too much pressure, etc. I think you are on the right track replacing or find a good resharpening service if it is a very expensive blade. Do you have a double bearing quill?

[wdelliott]

No, I do not have a double bearing quill. Could you explain how that feature impacts this issue? I am not moving the quill.

[dusty]

No, I do not have a double bearing quill. Could you explain how that feature impacts this issue? I am not moving the quill.

The arbor shaft, to which you mount the saw blade, goes through a bearing in the quill. If the bearing is bad, it may cause the arbor shaft to run untrue (the blade to wobble).

[JPG]

The blade 'wandering off line' is both a cause and an effect. If the blade gets hot it will not travel in a flat circle. That makes it wander and then get even hotter . . .

Plywood blades have little(if any) kerf so there is little to no clearance for the blade(like hollow ground blades). The hollow ground blades have no clearance at the periphery, and minimal clearance towards the center. Mine are only 'ground' a couple of inches towards the center. The center is thicker than the kerf.