In yesterday’s video I rechecked the runout on my arbor and blade after cleaning them. I was concerned because the runout at the blade was .003”. Turns out that’s not too bad.
I couldn’t stand not knowing so I did the math.
This is a scaled drawing I did in AutoCAD. Point A represents the bottom edge of the arbor flange. Point B is a point .001” out from the top edge of the arbor flange. Point C represents the top edge of the blade. I extended a line from point A through point B past point C.
It turns out that if the runout at the edge of the arbor is .001 the runout at the extreme edge of the 10” blade would be .0025 or two and a half times.
If you consider that the same .0025 will also go in the opposite direction on the other side of the blade then Paul Anthony was correct. A .001” runout at the arbor will translate to a .005” runout at the edge of the blade assuming you have a blade that is perfectly flat.
As always, I live for your comments (wait, did I say that out loud?).
-- Jerry Boshear, Professional Kitchen Designer, amature woodworker.