Just started working on the rudders for the Nacra 5.5 uni overhaul. Overall they seem in pretty good shape. I'd just like to strengthen any worn areas (rivets) and make them reliable, while taking out some slop where I can. I'll be adding all new down-lines and up-bungee. I'm aware that many get rid of the bungee and install pull-up lines, but I don't want to go there just yet, and will try to get the original system working well. I'll outline my basic questions directly below, then there is a link to pics and more detail over on the Beachcats forum. I've searched the internet for everything related to Nacra rudders, and have read countless pages here and elsewhere. I've found many good tips and tricks. Nonetheless, I still have some unanswered questions.

1. Pivot hole in blades worn and sloppy. Fill and re-drill? Use existing holes and pad insert with epoxy?
2. Castings are not the type with a delrin screw for blade rake adjustment. How major is this going to be in tuning the helm pressure?
3. bolt through end of tiller tube from cross-tie attachment is badly worn/oversized. Can I cut off an inch of tiller tube and drill new holes?
4. Add a sheave on the pin in the casting that the pull-down line runs over?
5. Proper hardware for each end of pintle?

Pics and more descriptions of what I'm working with over here at Beachcats

Thanks as always

One thing I'd like to add FWIW

On my 6.0, I did away with the bungee uphaul- it always puts tension against the downhaul, etc.
Instead, I put a line and a seperate cleat on the side of the tiller arm. That way, they would drag in the water and still give you some control, and pulling on the line and cleating it kept it up when it needed to be up.

I also would get the lock down thingy (forget it's name), about 1-2 inches from lock down, cleat the line in, then lock it the rest of the way down.
This technique always kept it from 'backing off a bit' when it was locked down.

* That's my old 6.0 in my avatar, with my wife and I

HTH
FWIW

Cool looking CAT !!!

On your lock-down cleat ; if your rudder hits a log, will
the line release ? I got spring loaded centerboards
on my H-21se ; so they go up if i hit something. Next thing
down the line is my rudder ; and i Like your idea !!!

Bille

Use a line that stretches. Trying to preload the line is unnecessary. I have this system and I use 1/4" 3 strand nylon.

Last night i woke up at 4:am ; was trying to think of a way
to place the jam cleat for your line, on a release of some-sort
that would let-go at a predetermined pressure ?

Bille

I think they have jam cleats that one side lifts up at a certain pressure.

My rudder has cam cleats that over-rotate when the rudder hits something, allowing the down-line to slip through

V-jam cleat with release cam. They have a little off-center disk on the bottom of the cleat that you can rotate which will fine-tune the release pressure. Falcon Marine used to use these on the F16 rudder systems (I'm not sure if they still do or not).

http://www.go2marine.com/product/209777F/sea-dog-jam-cleats-clamcleat-auto-release-racing-mini.html

Forums are GREAT for information ; i "Like" that
V-jam cleat with the release cam !
Awesome solution !!!!!!!!!!!...

Bille

indeed! The first time I saw them was on the Falcon F16 and I thought they were ingenious then and now too.

Is this the same thing that Nacra used to call the "pivmatic"?

similar concept but different. The pivamatic is this thing:
http://www.thebeachcats.com/gallery...p;g2_itemId=112994&g2_serialNumber=3

No. The pivmatics are a trimmed up fiberglass tube with a clam cleat riveted to it. Those other pivioting clam cleats are not very robust. They are ok if you rarely hit the bottom. A friend tried them and they failed after a couple weeks.

Fairly sure the outer tube of a worn out Hot Stick is the same diameter as the piv's. lacking that you could lay some glass up on the tiller tube. Trim it up and install a clam cleat.