I recently bought a new Dewalt DWE7491RS table saw (pictured below). And on two separate occasions the arbor nut has come loose on me. Once with a dado stack that threw blades across the room! (Very SCARY!)
The second time it was when I was taking a standard cross-cut blade off and noticed the tension on the nut was very loose, although the blade hadn't slipped out of place yet.
I'm almost certain that I am tightening the nut down pretty well; probably more than I should. And I do put the washer on the nut between the blade and the nut. This is also with all stock parts that are less than a month old.
Any ideas what might be causing this to happen?