Everytime I try to edge joint a board that is 3 1/2 feet or longer, I end up with a hump in the middle or the infeed end of the board becomes narrower than the middle and outfeed end of the board. I have 2 jointers and end up with the same result on both so it must be me. Any suggestions on what I'm doing wrong?
Thank you,
Abram Godshall