Help with this rudder cam issue please.....

Have read the previous posts and the article by Matt Miller about cams/rake etc but it isnt helping!

The delrin screws are as tight as they can go (presume there is some corrosion or something built up stopping me-but they are pretty tight anyways!- have pulled out the old ones and replaced all but the spring) and then today as another measure i have been putting bungy around the lower and upper casting ...basically to hold the cam down in place...cam is locked but seems to kick up when we are at speed....also when we fly a hull i can only assume the pressue on only the tip of the rudder causes it to pop up too......having bungy around the casting can create issues when we arrive at the beach too....it also makes it hard to lock the rudders down at first!....i hope someone can understand what i am talking about.....

See i live in New Zealand ...today we had 25-35 knots of wind....and a brand new sail (imported direct from Hobie USA) so looking forward to 2mmorow and the 15-20 knots we are expecting...just wish i could suss the rudder issues!!!!!

Many many thanks!

To clean out the thread in the casting go to the hardware store and get a 3/4" x 6" bolt (or correct metric size if differant than USA) and run it in and out with some oil. You can take a 4" hand grinder with a metal disc and cut a couple of grooves in the bolt and it acts as a tap. When trying to get a good grip on those screws I have heated up a large screwdriver and sunk it in perpendicular to the factory slot. If you get it so the screw goes in well and you run out of adjustment then maybe you do need a new spring. Make sure you lube the cams with waterproof grease or spray regular with silicon. Good Luck.

This may be related to the upper casting / cam plate position (assuming the boat is mid 80's or newer... if older, it will be a rudder drilling issue). If the cam plate is too far forward, it prevents the cam from fully locking, you get what appears to be a locking cam, but it trips too easily.

Hold the tiller arm up, lock the cam down with your thumb. Look at the cam from the front of the casting. There is a small rectangular opening in the front side (under where the tiller arm would normally be). Mark the casting with a scribe to align with someting on the cam. There is a sharp edge on the cam to use as a guide for a properly rotated and locked cam.

Open the cam with a blade screw drive. Lock the rudder down in the normal fashion, with the tiller arm.

Look again at the cam through the small opening of the front of the casting, under the tiller arm.

Likely the cam is not fully rotated and locked.

If this is the case and you have adjust the cam plate aft. Loosen the screw / bolt holding the plate. Move the plate all the way aft. See that the cam rotates and locks fully. Hold the rudder forward in the lower casting. With the tiller arm in the normal locked position, move the plate forward slowly until it contacts the inside of the cam hook. Lift and lower the tiller arm slightly to be sure the plate can seat fully in the cam (may be that the tiller arm will be slightly lifted off of the lower casting). Tighten the cam plate. Check the cam lock and rudder slop. If the plate is too far aft, the rudder can move aft under load. It will be a balance between holding the rudder forward and allowing the cam to lock fully.

I have seen systems where the plate is not properly aligned with the cam hook. The cam rotates over and hit the top of the plate and cannot lock. I have also seen systems where the castings have to be filed down a little to allow the upper casting to propery nest with the lower and get low enough to engage the cam hook.

Anyway... lots to look at.

Hello Scott,
Not sure where in NZ you sail from, but visit our website
http://www.hobiecat.org.nz
and make contact with your nearest fleet (or call me). I am sure we can help with your rudder cam problems.
Stuart

I have an old Hobie 14. I've had a similar problem with the rudder appearing to be locked down but popping up too readily. I installed a new cam but the problem persisted. I discovered that the pin on the tiller is too wide for the slot in the cam, so I ground the cam down to make the pin a neat fit ... but still had the problem. Finally I discovered that the holes in the rudder were the correct distance apart (90.05 mm), according to the spec, but seemed to be 2mm too close together. I redrilled the rear hole and now it locks perfectly.