Spent 4 hours figuring out why my miter saw cuts were off by 3 degrees

I was fighting with a baseboard install last Tuesday in this old house in Portland. Kept getting these tiny gaps at every corner joint. After remeasuring everything twice (and getting real frustrated), I finally checked the saw blade with a square. Turns out the blade was slightly bent from when I dropped it on a job site last month. Who would have thought a 1/8 inch wobble could throw your whole crown molding layout? Anybody else ever chase a problem that long only to find out its something simple like that?

2 comments

2 Comments

shah.shane4d ago

Close but you missed something. That 1/8 inch wobble you're talking about, that's actually runout on the arbor or the blade being out of true, not a bend from dropping it. A bent blade usually shows up as a consistent wobble across the whole blade, but a drop often just dings the teeth or bends the plate in one spot. If you squared the blade to the fence and it still cut off by 3 degrees, the arbor might be a little loose or the blade's not sitting flat on the flange. Did you check if the blade was seated clean and the washer was snug?

patricia_rodriguez4d ago

Oh come on, you're all overthinking this. Has anyone actually checked if the blade's flange or the washer itself is warped? I had a saw once where the flange looked totally flat but was actually slightly cupped from an old drop. That tiny gap made the blade sit crooked no matter how tight the arbor nut was. You can chase arbor runout all day but if that flange is off even a hair, you'll never get a true cut. Did you try flipping the blade around or swapping the washer just to rule it out?