Scott
Following are some measurements I took from my O"Day 25 rudder.
From the bottom of the lower pintle:
6 1/2 inches down to where the forward extension of the rudder blade begins,
38 1/2 inches to the heel of the rudder blade.
The rudder blade is 17 inches wide through out.
The blade extends 1 1/2 inches forward of the pintle for counter balance.
The heel of the blade is rounded on the bottom forward corner, 4 inch radius.
The drag of the blade bottom is 3 1/2 inches, aft corner lower than the heel.
The blade thickness is 1 1/2 inches.
The blade is horizontally convex its entire width although only slightly so in the mid third, about 3/8 inch.
The forward convexity terminates in a 1/2 inch bull nose on the forward edge.
The aft convexity terminates in a 1/8 inch bull nose on the trailing edge.
This is only a basic description of the rudder blade but close enough that maybe you can fake the rest. The foil section doesn't appear all that sophisticated.
Good Luck, George
