Keep in mind, when bending offsets, the conduit will shrink. If bending at 10 degrees, the conduit will shrink 1/16" for every inch of rise. 15 degrees is 1/8" for every inch, 22.5 is 3/16", 30 is 1/4", 45 is 3/8" and 60 is 1/2". Example: For a 4" offset height at 30 degrees, place your first mark at the distance from the obstacle then add your shrinkage calculation. 4" multiplied by 1/4" is one inch. Add that to you distance of the obstacle, so your first bend point will be at 31". Multiply your height (4") by the multiplier of 2 so your second mark will be at 39". This will give you a perfect offset bend.