You followed the instructions? I never had problems, the few times I did that. Just made a grid of the size I wanted to use, then sketched in the lines from the original grid. Had to redraw some lines, but the end result always came out to scale.Those old grid-ed drawings bring back bad memories of trying to copy the half scale plans and scale them up when I was a kid. I never quite got the exact curves, regardless of how easy the instructions made it sound.