NOTE: 06-12-07 HOBIE IS NOW PRODUCING THE BALANCED RUDDER, MAKING THIS MODIFICATION UNNECESSARY. THE HOBIE VERSION GIVES AN EXCELLENT RESULT AND HAS THE ADDITIONAL STRENGTH OF ALL SIX SCREWS.
For those who are experiencing a heavy helm with the AI, here's a "how to" for improved rudder balance. When done, it should feel much lighter to the touch at speed. The rudder will be remounted forward by one screw position. This requires some minor modifications to both the rudder and Twist & Stow (T&S) mount, so lets begin:
Tools needed -- Phillips screwdriver, hack saw, file, drill, pencil, ruler.
1. Modifying the T & S rudder interface:
--position the hull upside down on a set of saw horses for easy access.
--remove the rudder and set aside.
--find the three protrusions on the T&S rudder interface that must be filed/sanded off*. (* update 04-18-07 -- Yakaholic pointed out it is not necessary to remove the forward notch (right side of picture below) in order to make the mod; the modified rudder will butt right up against it). Here's the "before picture:
and the"after" (you can do this without dismounting the T&S):
2. Modifying the rudder head:
-- there will be two areas to trim at the rudder head; you'll cut off a portion forward of the upper middle nut and trim the drop-off behind the aft upper nut as shown (upside down in this view):
Here's another view of what it will look like when done:
Finally, here's what it looks like when mounted. Take a good look at your two clearance areas before cutting. Notice you have to leave clearance for the notch flange (shown on the right):
3. Re mounting the rudder:
-- You'll have to move three of the four holes in the T&S slightly. Begin by screwing the rudder on using the hole shown. Check for proper fit and alignment before tightening:
-- re-align the other three holes using the drill and insert the screws:
4. Trimming the rudder for hull clearance:
--mount the rudder in the full down position and place it next to the hull. Using a pencil, mark the overlap area on the rudder:
--add about 1/4" to your line. this will be your cut line. It should look something like this ( I marked a one inch reference line so I could give you my final cut out size -- coming up next:
re-trim as necessary. My cut-out was four inches long, cut in one inch at the top and 5/8" at the bottom; then trimmed and rounded with the file:
Here's the final product:
Not nearly as difficult as it seems. If you have any questions I'll try to answer them. You can return the rudder to its original position if you don't like the results; it just won't look as pretty. You can also adjust the balance beyond this, but we can cross that bridge later if anyone wants to.
As to the question of strength, I believe the original rudder mount was waaaay over engineered. As modified, everything feels very solid -- I don't see it as a cause for concern.