Size changes over cutting of multiples

I have been having issue with shrinkage of some mortise in some stool seat tops. I thought it was perhaps due to slightly differing thickness of ply… but after being super diligent about checking I keep getting smaller openings as I run the art on new material sheets. By the 3rd sheet of plywood it is too small to fit properly, with no changes in settings or thickness.

Has anyone experienced this or have thoughts?


Welcome to the forum. Are you using the same bit on all three sheets? If not there can be some slight differences in the actual bits that I have read on this forum.

I have not experienced this issue myself.

It’s the same bit for each run, nothings changes except a new sheet of ply is locked in place…

A little annoying withe the waste and the cost of wood right now.