CP 16 RUDDER Questions

[atrometer]

On my (new to me) CP16 the rudder blade swings up/down VERY easily.  There is no push/pull mechanism as there is on an IDA sailor.  It seems to me if you're sailing at 5 knots the water will RAISE your rudder blade at least partially?  I've also noticed that it appears the bottom of the rudder blade is a little lower (deeper) than the keel?

[marc]

I had a similar problem on my 19 with the rudder lifting when underway.  I ended up putting a clevis pin through the rudder head just aft of the blade. It's easy for me to reach over the transom and remove the pin if necessary. I'm not concerned about the rudder hitting bottom since my sailing area is all deep water.
Marc

[Jason]

Hi,

The bolt around which the aluminum rudder pivots is designed to be used as the pivot point for the swing-up rudder and also as a mechanism to tighten up the assembly so that the rudder does not swing up under water pressure alone.  There is a threaded handle that can be tightened so that the rudder does not swing up too easily (the handle can be seen in the photo in the post above), however over the years it may have been lost and may be replaced by a nut.  If you're missing that handle you could make one or probably order one from Hutchins in Clearwater FL.  Careful not to overtighten it, I tighten it just enough to keep the rudder down when making way.  A small line attached to the sternmost upper corner of the rudder blade is used to swing the rudder up.  There should be a cleat on the rudder stock where this small line is cleated to hold the rudder up when needed.

I replaced my stock aluminum rudder blade with a new one from IdaSailor, and I tighten the new rudder blade in the same fashion.

Hope this helps

Jason

[Pacman]

A clevis pin as shown above might be fine in deep water but if you hit an underwater obstacle something will break.  
It could easily tear the whole rudder assembly off the transom at the pintles - doing severe damage to the transon and risking sinking the boat.

Tightening the pivot bolt enough to clamp the blade might work too but it can deform the aluminum casting.
(I had a Catalina 22 that used this method for keeping the rudder blade down but it had a rudder blade that was a tight fit in the rudder casting so deformation was minimized.  My C-16 rudder blade has more clearance and would require more deformation of the casting to be sufficiently tight to hold the rudder blade in position.)

There is a much easier and safer way:

1. Drill a small hole on the leading edge if the aluminum rudder blade.

2. Insert a light line through the hole and tie a secure loop.  
(I use nylon line from Home Depot that is much like large fishing line.)

3. Take the free end up to the top of the rudderstock and tie it off. (a small cleat would be nice)

If you hit an obstacle the line will break so the rudder blade can fold back with no damage to your rudder.

[Pacman]

It seems to me if you're sailing at 5 knots the water will RAISE your rudder blade at least partially?

No.  The rudder blade should be down when sailing. 

If the blade comes back and up, it will greatly increase the tiller pressure required to stay on course and it will require a lot of effort to steer.

[Pacman]

I've also noticed that it appears the bottom of the rudder blade is a little lower (deeper) than the keel?

Yes,  That is a good thing because it serves as an early warning of shallow water before you run the keel into the sand.

If the rudder touches bottom you know it is time to head for deeper water.

[skip1930]

The CP-19 is fitted with the 'first' generation of the IdaSalor rudder which is not fitted with any lift rods or hold down 'detents'.
Just loosen the original jam bar that pinches the cast aluminum head onto the rudder and pull up the rudder with a line, and dog the line down.

The rudder even though it sits on bronze shoulder bushings still hangs down below the keel [+6mm] by about a 1/2 inch.
Being tired of pushing the rudder blade back down after the seaweed popped it up there is now a drilled hole and a shear bolt, later just a pin keeping it down.

It is noteworthy that these rudders be pushed 'hard forward' giving a bit of balance feel to the tiller. This rudder's leading edge is under the hull.

skip.

[Bob23]

If you look closely in this photo, you can see the downhaul I devised when I built my wood foiled rudder blade:


  I removed the gudgeon and installed a pad of 5/8" marine plywood with a vertical groove routed out in the front of it. A line runs from the back edge of the rudder, up along the transom in the groove and enters the cockpit through a PVC pipe I inserted through the transom. The line is held by a jam cleat just above the hole. Does that make sense?
  It works ok but due to the blades tendency to float, it still kicks back a bit while under sail. A second attempt is in order for the spring.
Bob23

[Pacman]

Bob23,

That's it exactly.

You might try a small cam cleat on the rudder stock so you can snug your line to keep the rudder blade in the forward position.

If you use a small cam cleat it will pull free if you strike an underwater obstruction.

Looks good.

[capt_nemo]

atrometer,

As Skip pointed out, ALL RUDDERS, whether they be original factory or foiled replacements, MUST BE SECURED IN THE FULLY FORWARD POSITION!

A rudder even SLIGHTLY back from its most forward position will cause noticeably increased weather helm when steering the boat depending on how far back it is out of "working" position.

Many complaints of "excessive weather helm" are due in large measure to a rudder out of designed "working position".

Photo of a rudder left to gravity to find its own position before tightening.




Photo of same rudder PUSHED forward as far as it will go before tightening. Toggle back and forth between the photos to notice TWO things. First, in its proper position (below) the leading edge of the rudder is parallel to and follows the transom line. Second,  the bottom tip of the rudder below "in position" is about 6 inches forward of the tip of the rudder "out of position" above AND is actually UNDER the hull of the boat.





Hope this helps.

capt_nemo

[atrometer]

I called Compac for an "official" answer.  They said I needed the "lever" to tighten the bolt, and they cannot recall a broken casting unless perhaps over-tightened.  (Just snug enough to hold it down).  I ordered the bolt and lever. They did know of one case of someone using a wooden dowel - rudder destroyed.  Thanks for all your help and advise!!!!

[marc]

I had discussed the need for a shear pin or some type of rudder hold-down arrangement with the customer rep at Rudder Craft. This is what he recommended:

It is a delrin shear pin that is suppose to break before the rudder does.
At this link - http://www.ruddercraft.com/catalog/product_info.php?cPath=60&products_id=298, it gives an example of the pin's use on a Macgregor boat and says it will release with 150 lbs of force. Can someone elaborate and tell me how much force that is? I've got nothing to relate it to and don't know whether it would work on our Compacs or not. It certainly would be more forgiving than the stainless steel pin I'm currently using!
Thanks for any input.
Marc

[Pacman]

The delrin shear pin is a brilliant solution!

It will positively hold the rudder in the correct position yet it will shear upon impact thereby preventing damage to either the rudder or the boat.

My light line accomplishes the same goal but the delrin shear pin is simple to use and inexpensive too.

I think that is the best solution discussed so far.

Kudos to Ruddercraft for that one.

[NateD]

In a previous discussion on the shear pin topic (http://cpyoa.geekworkshosting.com/forum/index.php?topic=6883.0) people suggested: plastic bolts, golf tees, wood dowel, zip ties, or piece  of rolled up beer can. It seems that a plastic bolt (either from Rudder Craft or the local hardware store) is a good choice.

I image 1,200 pounds moving at 1-2 knots would generate 150 pounds of force on the tip of the rudder if it hit something, although I have no math to back it up.

[nies]

Going back to previous disc., a drilled hole with a shock cord of proper length provides a safe alternative, cheap and quick..................no worry about pressure to shear anything, works on my boat....nies