I posted this on another thread so forgive the duplication:
"I have noticed that these ballast boxes are positioned in the middle of the 3pt. Is that the optimal positioning of ballast? Reason I ask is that I hang 2 metal plates off my blade by hooks and I can put them just about anywhere along that 7' span. Normally on my 8N I had them equal distant from the middle (3pt) to the ends but don't know why."
Update: I put the weights as near the middle of the blade as possible, one on each side.