Damage to upper leading edge of rudders?

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gahamby
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Boat Make/Model: SuperCat 15#315
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Damage to upper leading edge of rudders?

Post by gahamby »

I have sought but have not found.
I'm working up a spare set of rudders. One had a fair amount of damage on the upper leading edge.
This location is above the taper where the rudder impacts the lower gudgeon when the rudder rotates too far forward.
This seems to be caused by play in the down position notch. There is quite a bit of for to aft play.
Is there a preferred method to remedy this situation?
I could fill in the front of the down position notch but this could make lock down difficult.
I have also considered installing a bumper of some kind either on the leading edge of the rudder or inside the casting at the front.
There is plenty of room for reinforcement on the leading edge of the rudder.
If there's a post I missed, please point me to it.
Does anyone else have a solution besides yearly application of your favorite thick stuff?
The other rudders in my possession also have this damage to a lesser extent.
I have repaired the operational set.

Any recommendations will be greatly appreciated.
Thanks GH
Kevin Keller
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Re: Damage to upper leading edge of rudders?

Post by Kevin Keller »

Can you send pictures of the slot with the roller in? What is the diameter of the rollers? I believe they should be 3/4" Maybe you could install a larger diameter roller.
gahamby
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Boat Make/Model: SuperCat 15#315
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Re: Damage to upper leading edge of rudders?

Post by gahamby »

Kevin, Thanks for the reply.
The rollers are the stock Aquarius replacements of recent vintage. I don't think upping the dia. of the rollers will solve the problem. It would tend to force the leading edge forward into the gudgeon on a constant basis. I am thinking of installing a rubber pad on the leading edge of the rudder blade where it impacts the casting and lower gudgeon. I might also fill in the forward part of the down position notch.
Here are two links I found that demonstrate the issue. [credit: Mac M]

https://www.youtube.com/watch?v=5-KDpz7PJnM

https://www.youtube.com/watch?v=iDUtuK7qAec
Matt Haberman
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Re: Damage to upper leading edge of rudders?

Post by Matt Haberman »

Appears to me that the rollers and pin are bottoming out in the rudder casting and not seating properly in the rudder notch, thus answering the rudder to rock back and forth. It could be a couple of things, but I would be suspect of the pivot hole location. If this is the case the correct solution is to fill the pivot hole and redrill the hole in the correct location.
Matt Haberman
Aquarius Sail Inc.
http://www.aquarius-sail.com
gahamby
Professional
Posts: 187
Joined: July 24th, 2012, 7:02 am
Boat Make/Model: SuperCat 15#315
Location: Falls Church VA 22042

Re: Damage to upper leading edge of rudders?

Post by gahamby »

Matt, thanks for the reply.
I'll have to take a look at that.
gahamby
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Joined: July 24th, 2012, 7:02 am
Boat Make/Model: SuperCat 15#315
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Re: Damage to upper leading edge of rudders?

Post by gahamby »

Well I had a look at the rudders.
I couldn't see down into the notch. I could slip a 24ga. shim down there. The rollers will spin but not freely.So there's a little room at the bottom of the notch.There is about 1/8" of room at the forward end of the notch.
I think the impact occurs when pulling the rudders down. With the rollers pulled up the rudder can over rotate. It's possible to get the rollers forward of the down position notch.
On the subject of filling and re-drilling the pivot bolt holes: I knew going in I was going to have to re-drill the spare with the worst damage.
How do I locate the pivot bolt hole precisely? Is there a template available?
Thanks GH
Matt Haberman
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Re: Damage to upper leading edge of rudders?

Post by Matt Haberman »

The rollers typically should not be able to rotate when fully seated. Depending on the vintage of the rudders and which molds they came out of some of the notches were a bit wider then ideal. In those circumstances we have been able to add a little fiberglass patch to buildup and reduce the width of the notch which can help, however this making any difference is predicated on the hole being drilled in the correct position. We have a drill fixture that is used to drill the rudders and doing it without the fixture can be tricky. I would suggest calling Tom during the week and discussing your options for re-drilling.
Matt Haberman
Aquarius Sail Inc.
http://www.aquarius-sail.com
Kevin Keller
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Re: Damage to upper leading edge of rudders?

Post by Kevin Keller »

It is easy enough to take the rudder apart. By doing that you get to see the size of the pivot hole. You also get to see the width of the notch that the roller goes into. This should give you all the information you need to figure out what is wrong.
gahamby
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Re: Damage to upper leading edge of rudders?

Post by gahamby »

Thanks again for the replies.
I have taken the rudders apart any number of times. What you can observe about the position of the rollers in the down notch is limited, even with the springs, nuts and washers removed.
I would have to "move" the pivot holes up about 1/16" for the rollers to bottom out.
The forward part of the down would have to be built up about an 1/8" or more with glass and resin. There would then be a trial and error period involving a file and sandpaper. I could just pad up the bottom of the notch. That would be less of a pain than filling and re-drilling the pivot holes. Three out of four of the holes are the right size.
If locating the holes in the exact right place involves shipping to and from the factory plus labor and materials, it would not be cost effective.
I assume there are no plans or dimensions of the rudder blades available for download.
The spares I bought arrived dissembled. They will need a number of new parts. I'll have that conversation with Tom when I place the order.
Thanks for the input. Please keep it coming. GH
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