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Miter Saw Accuracy

SawGear is an accurate measuring tool, but when cutting angles using a miter saw, the saw must be accurate too.

Miter saws rotate around a center called the 'pivot point.'
The pivot point must be in exact alignment with the saw's back fence.
Some miter saws have an adjustable back fence; others do not.
If the pivot point is not in correct alignment and the fence cannot be adjusted, accuracy can be maintained by adjusting the length entered into SawGear by the amount of offset observed.

When the pivot point is in exact alignment, all your cut lengths, straight, inside and outside miters, will be exactly equal.

Don't settle for less than perfect! Dial in your saw!

Click on the image to zoom.

Click on the center of the image to zoom in on the pivot point.

This example assumes that SawGear is on the right of the saw, and that the observed pivot point is on the right side of the saw blade.

You can check for accuracy by comparing the straight cut and the left and right miter cuts:

End trim a sample board so it has a clean, square right end.
Using a tape measure mark 8" from the right end with a pencil and square.
Line up the pencil mark with the right side of the saw kerf, and clamp the sample board flat up against the back fence, keeping the clamp away from the path of the saw blade.
With the saw set at 0° make a partial cut into the sample board. This is the straight cut.

With the saw set at -45° make another partial cut into the sample. This is the outside corner miter cut.
With the saw set at 45° make another partial cut into the sample. This is the inside corner miter cut.
Unclamp the board and measure carefully from the right end of the board to each of the cuts. If the pivot point has been correctly adjusted, all three cuts should be the same. If they are not, readjust the back fence, and repeat the test process.