rudderd locking mechanism

In my continuing quest to resurect a derelict H16 I have come to my next hurdle: The rudder locking mechanism and cam on both rudder castings is shot. Replacing the cams does not look like a problem. One of them has already been drilled out and replaced with the screw insert. The problem is getting out the Delrin screw inside the casting. They are both frozen solid and one of them is broken off. How do I get them out?!?!?

As an aside, I've finished repairing the hulls and added two layers of glass tape to the keels using West System epoxy. They look and feel good. Next is painting them...

Antony Dalton
Tampa, FL

Discussion on Delrin screw replacement:

Delrin screw discussion

FAQ on cams and rudder adjustments:

http://www.hobiecat.com/community/viewtopic.php?f=18&t=467

Awsome! Thank you so much. Between you and the rest of the guys on the forum I will have "Road Kill" back on the water in no time.

Antony

I seem to have to do this every year........I think my lower castings are warped or highly worn though.

Keep them lubricated too once they're back together.

Just a follow up with the Delrin screw discussion link from Matt....the luggage scale I used to set the tension worked well except I set it to the upper range at 25 lbs which was too much and caused one of my cams to shear instead of kicking the rudder up. I backed off a full turn of the Delrin screw and it has worked well all summer. Wrapping the screw with teflon tape also worked out well. The screw is snug (after tapping out the rudder casting) but still turns easily. And I doubt the screw,lined with teflon, will ever freeze up again.

Here's a great way to remove the Derlin screw, without risking damage to the threads.

Get the biggest, longest screwdriver you can find that will fit in the screw head.

Heat the screwdriver until it is very, very, very hot (such as, put the tip of the screwdriver in the flame of a BBQ grill for a few minutes).

When it's hot enough, immediately put it into the screw and push it in as the Derlin melts. Make sure it goes into the screw at least 1/2 inch. DO NOT turn the screwdriver while doing this.

After you've made this new slot in the screw, remove the screwdriver. Pour cold water over the screw so the plastic hardens. Place the screwdriver into some cold water (such as in a cooler with ice).

When the screw and screwdriver are sufficiently cold, insert the screwdriver and remove the screw. If the screw is really stuck, it helps to use a pair of vice grips on the shaft of the screwdriver to add leverage when turning.

The beauty of this method is, you don't destroy the screw (it can be re-used) OR the threads, and everything you need can be found on the beach at a typical Hobie event!

Mike

I’m still facing some problems with my rudder cams. I dis-assembled all items - even delrin screws went easy - and replaced the rudder cams. My first problem seems to be the special shaft (splint ?) that should hold the cam and keep itself in place because compression is needed while assembling. Even new ones seems to get loose after a short while after which the rotating centre of the cam gets out of place. I intend to order special rudder cam pins (solid tight fit shaft with countersink head and countersink screw) to solve this problem. Or have them made locally (stainless steel). Looks like my castings are slightly worn out but testing with a ø 6 mm axle doesn’t say so…
Next problem is proper adjustment. When done as described in one of the previous replies to this topic I need to apply quite some pretension in order to keep my rudders in position at high speed and when hitting plants etc in the (sea)water. However when tested by hand the rudders kick up quite smooth and with the rudder cam in right position. So far so good. However when I want to release my rudders by lifting the helms when sitting on the trampoline the starboard rudder is no problem. But the portside rudder demands quite some force. When released the rudder cam is in the right position. I used WD40 and grease on silicon base. Can not find any reason for the large difference.

I'm not sure releasing the rudders by lifting the rudder arms or tiller crossbar is a good idea. You are putting upward lift or force on the weakest part of the plastic cam. When the rudders kick up they are putting forward thrust on the cam to rotate it. My rule of thumb is that if you can lift your crossbar at sea, your rudder locks are not properly adjusted. In your case the starboard rudder.

That is incorrect.

Every racer pops their rudders this way - some guys can do it from the wire with their feet.

It's the only way to protect pricey EPO rudders from damage when coming into shore. I never let the rudders kick up on the bottom.

Word.

If I try to lift the rudder arms or tiller cross bar to unlock the rudders it works, but the cams do not rotate so I can not lock the rudders back down without manually rotating the cams first (usually on shore with a screwdriver). Whenever I hit a shallow area, the rudders kick up fine and the cams rotate so that I can easily relock the rudders down latter. Evidently, pulling up on the rudder arm affects the cam differently than when the rudder kicks up after it hits something.

Thanks guys. Sunvistas reply indeed amazed me a little bit but actually for me it's reality. Thus I damage my rudders ...
Our cat-club has oa. a number of Hobie Tigers and Foxes. For some strange reason they don't seem to have this problem, although system is in principle identical.
Got a spare H17 rudder assembly on which I'm going to do some tests at home. Ideal would we computer animation to determine angles & critical area.
But on the other hand: being the largest cat class world wide >110,000 pcs > 30 years it can not be necessary to invent the wheel again. So surely I must be overlooking something or at least doing not the right way.....
Thanks for comments anyway !!

Still, they shouldn't pop up that easy. Nothing more annoying that hopping out on the wire, lifting the hot stick and having the crossbar pop a rudder up, or worse, the rudder arm comes up but the cam stays locked.

I don't have EPO rudders but was considering buying a set. Are they especially brittle or something? I always let the shore kick up my rudders.

Your signature clued me in to why this is happening - an '82 boat does not have the rake-adjustable castings. It has the fixed rivet/pin in the upper casting that engages the rudder cam when the rudders are locked down.

What's happening with your rudders is that when the rudder is "locked down", the pin is not seated firmly in at the base of the hook on the top of the cam. When you lift the tiller arm, the pin bears against the end of the hook, the hook flexes, releasing the tiller arm, but not rotating the cam.

When you come in to the beach, the force of the bottom pushes the tip of the rudder aft, forcing the pin into the corner of the hook, releasing the tiller arm AND rotating the cam to the unlocked position.

If you put the boat up on wheels or a trailer, you can see this happening yourself. Lock the rudder down, then pull gently aft on the tip. You'll see the rudder castings move relative to each other (slightly) before the pressure on the tip increases significantly.

With properly adjusted / drilled rudders, the castings do not move realative to each other until the cam starts to rotate.

This is easily fixed with the rake-adjustable upper castings; less easily fixed by re-drilling the rudders.

They are certainly not as tough as the stock nylon rudders. They don't flex - that's why they handle so much better. They're essentially fiberglass(carbon) and have a gel-coat like outer "skin". Rocks will chip them. Sand will make the clear coating turn hazy. You don't want to wear them down to the fiber, either.

I don't know about you, but I'm not dragging my $250 (each) rudders along the bottom. It's too easy just to pop them up before you hit.

Matt, Excellent post/point! (There's so much much info on the adjustable castings an SO many people sailing boats without them) Do you think this bending of the cam hook may be related to too much tension on the cam locking spring? I've seen countless, newly replaced cams, with buggered up cam hooks. Can spring tension be an attributing factor? Or is this primarily a case of worn castings allowing slop?

HUH? You've just reworded my earlier post #190696. Up cam force bad....forward cam thrust good. In my case there was no slop so lifting or releasing the tiller arm didn't rotate the (chinzy plastic gusseted) cam...it just broke it off at the hook. One thing for certain, shearing a $15 plastic cam is clearly preferable to fracturing a $250 rudder. Either one will sit you on the beach though.

Way cheaper to replace rudder cams than repair race rudders. The cams are super cheap anyway

Last year I overhauled my rudders by replacing the delrin screw, cams, etc., adding shims and redrilling the aft holes in the rudders. I tried using the templates for drilling but that did not solve the problem so I had to refill the holes with JB Weld several times and through trial and error was able to get them raked forward as much as possible with only about a 1/4" of movement foward/aft at the bottom of the blades.

Bill Mattson's May/June 1998 On the Wire "Raking Rudders, Correcting Helm on a Hobie 16" and David Hall's March 1997 On the Wire "Towards the "No Slop" Rudder" along with Gary Wilcox's April 1997 On the Wire "Rebuilding the Hobie Rudder Cam Assembly" articles were very useful.

Even though I have corrected the helm, slop and "break away" spring tension, the cams on my old style rudder castings will still not unlock when I lift the tiller arms (only when the bottom of the rudders are pulled back by hand or they hit bottom), maybe it would be best to upgrade them to some "newer style" used adjustable rudder castings. I may also try following the section in David Hall's article where he shows how using RTV and plastic wrap on the lower rudder casting (instead of the newer style adjuster screw 8032001) to fill the gap between the old style casting and the rudder may help push the fixed rivet/pin further into the cam so it will be seated firmly in at the base of the hook on the top of the cam.

If I replace the upper rudder casting with an adjustable upper rudder casting will I have to also replace the lower rudder casting with an adjustable lower rudder casting in order to get them to work together properly?

No. You really only need the upper casting.

No, I didn't.

IF the pin is not seated in the corner of the hook when the rudder is locked down, THEN lifting straight up on the tiller arm will bend the hook and release the tiller arm without rotating the cam.



The old style (non-adjustable) rudder castings are a PITA to deal with. You've got to get the holes in the rudder just right for them to work properly.

Grease is a cams friend. Failure to grease is what fails them... and they are only $7.50

Hey, if it works...don't fix it. I thought about doing the silicone caulk with cellophane trick but I was worried that a blob of caulk, after it cured, would block access to the delrin adjuster screw. I'm still not totally convinced the cam is designed to rotate by lifting the rudder arm. That's a lot of leverage at the weakest point of a plastic part. In fact, I believe the cams are gusseted plastic and not brass or stainless for a reason. So that they will ultimately shear under stress and not destroy the rudders or castings.

I did this earlier in the season. I was able to get one of the rudders perfect the first time out and the other is still not working properly. Since I have to do a bottom job on one of the hulls now, I am planning a trying the RTV trick again. This time I think I am going to clean out all of the RTV, redrilling the rudder and than applying the RTV. Whereas I had applied the RTV and than Drilled the rudder before.

Sam

Just to reiterate what Matt said these assemblies must be greased to work properly. A dab of grease between the plunger and the cam is essential.

I once replaced a cam and the first time I went to pop the rudder up the cam stuck down. :-( I greased it and it worked fine from then on.

cheers
Bill

You don't even need a new upper casting. It is pretty easy to remove the fixed crosspin, cut a slot and fit the adjustable cam plate and screw. I have done this to two older boats with no problems.

To cut the slot simply drill a hole where each end should be, drill as many similar holes in between those as you can and file out the remaining metal to form the slot. Borrow a later casting to use as a guide if you can.

To complete the job, you might want to drill and tap the lower casting for the small rake adjusting screw, but I'm not sure how important that is. Matt Bounds might have an opinion.

Cutting the slot in the top of the castings would not be that difficult. The old style castings do not have any raised edges for the cam plate to slide on. How did you solve that?

Thanks Matt for the advice.

I just replaced my old upper rudder castings with a nice used set of adjustable upper rudder castings from PreSailed Parts. What a difference, the cams unlock when you lift the tiller now and I was able to rake the rudders more so the weather helm is just right with a raked mast.

Maybe this will help:

Was looking at the You Tube vid and got me to thinking. The axle holes for the CAMS in my castings have become eliptical over time, so that the CAMS can move about quite a bit. Has anyone got suggestions on how to repair them? Should I drill out and use a bigger set screw for the axle (or whatever kind of screw thing that it is) or fill it all in with epoxy and redrill (will epoxy even bond with the casting)?

Appreciate any comments you may have.

Cheers, PT.

Sounds to me like it would be simpler to find some new or used castings. The newer adjustible ones seem to be a huge improvement.

Antony

Do a Google search for HTS-2000 brazing rods. Never personally used the stuff, but for a small repair like that, they sound like the ticket.

Sorry for the late response.

When I did it the first time I had never seen the inside of the factory adjustable arms. When I installed the plate and tightened the bolt, I relized that it needed a spacer of some sort, so I just stacked a few SS washers until it was standing proud enough to engage in the cam.

It worked perfectly and it was only when I bought a newer boat that I saw the cast-in rails inside the arm.

I have been pondering this for a while because the local sheriffs camp has about 20 16s and 14s that we are helping with. The rudder systems are horrid. Mostly old non adjustable castings. I had an idea for a simple modification that I would like to run by you guys. The old castings use a ss tube in a hole through the upper casting that is flared on both ends to hold it in place. What if I drilled that out and drilled/ filed adjacent to it to make a slot. Then replace the tube with a 1/4-20 bolt and nut with some star washers for grip. This could be adjusted in the newly made slots to get a proper lock down. The slot would only have to go towards the cam since these old systems are always loose.

What do you guys think?

That certainly sounds doable and easier/cheaper than the old EX Raker. A few thoughts (that you may have already considered):

If, like many old boats, there's excessive slop in other parts of the system (gudgeons, rudder pins, holes in castings for the rudder pins), this mod may not be real helpful in and of itself. It's hard to describe well in words, but, if there's slop elsewhere and the new slot is wide enough, it will likely be possible to slide the new bolt so far forward in relation to the pin/sister screws on which the cam rides that the cam will not have enough clearance to rotate properly. (This can occur with the modern adjustable system and the EZ Raker as well.) If adjusted with the rudder locked down, the cam will be bound and not rotate up; if adjusted with the rudder up, the bolt will be blocked before the cam is rotated all the way down. In such case if the bolt is slid back enough for proper cam rotation, the rudder will likely still trail back due to the excessive slop elsewhere causing unwanted tiller load. I guess the bottom line is that this mod cannot remove excessive slop located elsewhere in the system. While the rudder should lock/unlock better than it does now, this mod may not fully achieve the desired result without new rudder pins and/or gudgeon/casting bushings.

The length of the new bolt that will be inside the casting should not be threaded (for increased shear strength and minimization of damage to the cam).

This sounds like a lot of work, but for a great cause. Perhaps a local machine shop would contribute (free or reduced cost) services toward all of the needed mods in exchange for some public recognition?

I believe your idea has a lot of merit and would like to hear others' thoughts.....maybe you should revive this old Hobie Forum thread?: https://www.hobie.com/forums/viewtopic.php?f=14&t=63204

Good luck and please let us know how this works out!

Sorry, but you all are getting way over complicated here.

There is a method that we called, "cutoff cams" that is super simple and works really well. No parts to buy, machine, etc.

Will have to see if I can find instructions online.

I think I can cobble together a jig to hold the upper casting on a drill press in the right orientation. I think 1/4” of adjustment is all that will be required. Drill one hole next to the current hole and then use the drill bit like an end mill to create the slot. Of course this will not solve other worn parts but it will allow a bit of adjustment. If I get the ambition I’m going to try this on an old set of upper castings I have.