I came up with a unique way of finding the location of the center of each hole through which the 3/4" O.D. steel cabin brace rods would penetrate the turtle deck. I used a laser level and a card board tube placed over the brace mount to trace an ellipse on the under side of the turtle deck for both rods. I drilled out the center holes with a 7/16 hole using my stepper bit. I then used my hydraulic knock-out punch to create the 2 holes. In the Tools section I talk about the steel dimple dies I manufacturered for the hydraulic knockout punch to give the holes strength and a nice appearance.
