This kickup rudder post, again (long, so read/reply if so inclined, only):
I have scoured the forum and others for smooth elegant solutions/execution of a kick-up rudder and haven't found the holy grail, yet.
I certainly understand and appreciate John's philosophy of keeping it simple, whether it is a friction star knob or a cleat to hold the downhaul in place, or some other friction.
What I am looking for, is a smooth elegant system that allows the blade to stay extended, to retract if hitting something and to immediately spring back after passing the underwater obstacle. Of course, we need the ability to manually retract the blade and keep it that way for trailer recovery or beaching. I would like to avoid having to uncleat one line and cleat the other, back and forth.
I would like this to be adaptable to most any kick-up rudder from CLC, but to be clear I am trying to get this to work well on my Skerry (I tried a variety of ways, all of which work with more or less elegance, and more or less satisfactions of use). The problem arises, partly because the rudder is already built and it was the old model with the exit hole for the rudder downhaul, way up under the tiller horn.
Best way, but temperamental is the bungee cord for downhaul, cleated to a breakaway automatic cleat for added redundancy, and an uphaul to a jam cleat. The execution with this nordic type tiller is a pain, mainly due to location of cleats being either on the aft side of the rudder post, or somewhere on the horn, even perhaps on the stern of the boat via a through hull. None feel good, work well or are sightly.
Another issue, is the anchor location of the rudder uphaul/downnhaul on the blade. Close to the rudder post, and while visually pleasing, it is poor in terms of leverage/fulcrum and force required on the line. This is not to mention that in the absence of an off center protrusion to the rudder blade (whatever that is called in nautical terms), the line is lined up with the rudder and requires tremendous force applied to move it. A slight offset is needed. With the line further down the blade, the geometry is better for decreased pull force required, but the line is submerged in water and is likely not the most hydrodynamically satisfying method, albeit one that would hardly disturb the perfect of a Skerry.
The best way, so far in terms of ease of operation, for me, has been a 1/4" bungee cord as uphaul, attached to the leading edge of the rudder blade on one end, pulled semi taught and locked in place on top of rudder post (no ham cleat as shock cord thins when pulled and weaved sheathing frays from friction.) via a 1/4" crimp doohickey (whatever those are called).
For uphaul, a line is secured to the trailing edge of the rudder and attaches to a dual block. Another line wraps around said blocks to a fixed block some 9" up the post, giving it a 3:1 pull ratio, and the exiting line goes through the tiller horn to a jam cleat on the horn. Pulling said line raises the rudder blade against the tension of the downhaul bungee, while releasing the line from the cleat allows the downhaul bungee to kick the rudder down into the extended position.
While this works well with just one line, it raises a few concerns:
- bungee may lose elasticity over time.
- Bungee is crimped and may fail.
- Attaching bungee to small diameter line in rudder blade requires unequal line bends to join the two and the thickness increases, making it prone to jams in the tight slot where the rudder blade lives. A crimp of that size also interferes with slot.
- The uphaul contraption of blocks is unsightly and more difficult to execute cleanly than is wise.
- Location of cleats to minimize the need for fairleads, blocks, etc., to limit friction while having the system operable from the cockpit is annoying, at best.
I tried to replace the bungee with a C-237 utility ext spring (9/32 X 6 X .034) from Tractor Supply, and it works well but rusts after a short time.
Help. I am sure thar more/better ideas in the multiple brains on this forum, exist. This is only for those who, like me would prefer a more elegant, but functional system, even if it requires additional costs and complexity.
If thinking one through prior to building a rudder, I was toying with the idea of an internal mechanism inside of the rudder post, with a wooden access door for servicing, but to keep the looks.
Obviously, those in the KISS category will be happy to point out one of the existing solutions in the form of friction, knobs, or single or dual lines. I respect all of it, perfectly ... I would just prefer to find a satisfying alternative. Anyone? Bueller?