This is done by creating two rods and having the point in the middle near the middle and close to the dividing line. Now copy them and flip the two rods both vertically and horizontally. At this point it is important that you add a connecting rod in the middle, this rod does not absorb much stress it's main purpose is to keep the diamonds form and can be wood which 99% of the time will be adequate. keep in mind if you are on a Budget that a diamond brace made entirely of wood is cheaper than a steel one and almost as strong.