Here are some pics of how some personalized BB Hardware super-light .21 strut and rudder could look like on the transom of a outrigger.
SS 4-40 screws are used for mounting of the rudder and strut bracket and aluminum 4-40 lock nuts. The top screw that holds the rudder blade is a 6-32 SS button head and the lower brake away screw is a 4-40 aluminum (hole drilled through - no threads in rudder blade bracket).
I used a 90 deg M4 brass nipple bought from Frank Werner that I glued with ProSeal™ Pro Weld Quick glue. But you can use JB's version of that glue also. The nipple is glued at 90-deg left when the rudder is moved to full lock right... So at neutral the nipple points slightly forward.
The radius on the inside of the rudder bracket slightly interferes with the two outside mounting holes so I filed that part flat so the screw head would sit flat.
Steering linkage: Du-Bro #369 ballinks, Du-Bro #144 pushrod & Du-Bro #336 threaded coupler.
Aluminium #4 washers is used on the inside of the transom. Futaba S9551 steering servo.
Du-Bro medium silicone tube...
If you run your .21 rigger "old-school" style with a exposed driveline (and usually with rear sponsons) then you may want to modify your strut like this. I used a Dremel sanding drum (the smallest dia) and sanded it down towards the 1/4" K&S brass tube.
Note; the rudder blade is really, really thin and sharp - borderline too sharp/thin if you ask me. That is all good if you want to go fast but it makes the leading edge of the blade fragile. So I recommend you buy and extra blade right away and remove the blade from the bracket after each days boating. Store (and haul) the boat with it removed and it will last longer.
All screws are bought from Fastener Express.
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