On 1/29/2019 6:17 PM, dpb wrote:
....

I recommend to get some scrap stock of decent thickness, joint one face
flat and then run it through the planer several times.

It should subsequently measure identically the same thickness at all
four corners.
....

And, keep the same orientation each pass -- several passes in the same
orientation will let you determine a very small misalignment that isn't
apparent on only one or two by compounding the error each pass. Wider
stock is better test material, too, of course...

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