Leave the dresser lets say 2 degrees and then add more angle to the reg wheel. So adjust it to say 2.25 degrees and run some parts. If you are still getting a hour glass shape increase the angle some more until the part is straight. I like to see the parts stop grinding about 3/4 of the way thru the grinding wheels if that make sense.Not a dead try. Just a u-12 grinder and hourglass shape or s straight taper sometimes