Video: How To Make A Laser Rudder Vertical

Hi all,

Ed was curious as to how I made my rudder go vertical. I said I'd do a video. Here's the video.

Cheers,

- Andy

Nice job, Andy. And without Class racing worries you now have a faster, more efficient boat. My approach was to trim down a Hobie 16 rudder and make it vertical and use the extra 4 inches depth. Now we'll have to race on Tomales Bay and see who rules to weather!

Eyeper said:

My approach was to trim down a Hobie 16 rudder and make it vertical and use the extra 4 inches depth.

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I think Bruce Kirby said in a 1990s interview that the only things he'd change on the Laser were the control systems (which was done a few years later) and the rudder, which he would have made elliptical and deeper.

Thank you Andy! Now that I know, I'm thinking I'll get a non class legal practice rudder and modify that one. My GRP is just too new to chop on and I'd like to keep it legal anyway. Thanks again for your high quality work. BTW, the technical term for that line is a rudder downhaul, but I like yours better! -- Ed

chemprof said:

BTW, the technical term for that line is a rudder downhaul, but I like yours better! -- Ed

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Appreciate it Ed. Thanks to you, I'm one step closer to not sounding like a total Laser qeek!

Hey, maybe I should just call it, "The Rudder Cunningham".

- Andy

Andy,

Thanks for the inspiration. I gave the problem a bit of thought. I figured out that if you drill a new pivot point for the rudder bolt you can leave everything else the same. I took out my bolt. Placed a straight edge down the rudder pintels, measured a consistent distance along the blade, and marked the new pivot point.

I drilled it on my drill press. There are the steel reinforciing rods in the new hole location which is about 1 1/4" from the old one. The rudder must be clamped hard to the table or the drill bit will wander. I wouldn't try this freehand with a drill.

I plan on using the vertical position when using my Hanson Turbo rig or sailing in 25+knots with the full rig. Hopefully it will end the rooster tail and insane weather helm. Then I can move the bolt back to the regular location for club racing.

Cheers, Ahab

CaptainAhab said:

I gave the problem a bit of thought. I figured out that if you drill a new pivot point for the rudder bolt you can leave everything else the same.

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Brilliant Ahab! Why didn't I think of that?

- Andy

CaptainAhab said:

There are the steel reinforciing rods in the new hole location

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Ouch. You mean you drilled right through the rods? That sounds like an effective way of shortening the life span of the blade. They're not stainless steel.

LaLi said:

Ouch. You mean you drilled right through the rods? That sounds like an effective way of shortening the life span of the blade. They're not stainless steel.

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hmmm ... If you can still drill, you might want to oversize the hole and epoxy in a bronze bushing to seal. -- Ed

I can always drill...

The new hole is above and forward of the old one. The rods in the blade are discontinous thru the middle where the original hole is located. I will try it out on the water. If I like it I will drill it out to 5/8" and fill it full of epoxy/filler. Then redrill the 3/8" hole. That way the steel won't rust and the bolt is pivoting on the epoxy silica filler. If I don't like it I will fill it and forget about it.

I've had two centerboards in the past that both started to have surface rust and they were never damaged. I think the rods weren't set deep enough into the hard foam.

CaptainAhab said:

The rods in the blade are discontinous thru the middle where the original hole is located.

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I just had to get a magnet and map the rods on my mega-crappy old rudder blade... I have done it before but the pattern is simpler than I remembered. There are two parallel sets of vertical rods, less than 2 mm from each surface. They're located completely forward of the pivot hole, so there's nothing but foam between the hole and the trailing edge. But the distance between the aftmost rod and the hole is only some 5 mm, so you're bound to hit some metal if you drill forward of that.

CaptainAhab said:

I've had two centerboards in the past that both started to have surface rust and they were never damaged. I think the rods weren't set deep enough into the hard foam.

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It's not about depth. The interesting thing I now noticed is that the rust spots do not always coincide with the rods. The stains form a regular pattern of their own, as they're connected to tiny cracks which are likely a result of the manufacturing process. But there's no steel necessarily under those points.

I've got to drive to the workshop and get my drill...

1st test of the new offset pivot vertical rudder blade design.

Protected water 2-3ft waves. Near gale conditions. Blowing 27-30kts constant, 35-40kts chronic gusts.

Full rig Laser. 200lb 6'2" sailor. Excellent results. Almost no weather helm when boat is near flat. Flow reattaches instantly when rudder is recentered if stalled.

Unfortunately the load was too much for the crompton construction to handle. The foam cracked at both of the hole locations on oneside of the rudder. I had the rudder in kickup mode, which I suspect puts to much load on the rudder itself. In reality the Laser rudder head as designed distributes little of the rudder load to the aluminum side plates. If one was to tighten the bolt as tight as possible, then perhaps the second hole would work without damage. At the end of the day we don't know.

The biggest variable in the whole thing is the shoddy construction of hard foam and steel rods. Since I've come this far and the rudder simply cracked. I plan on boring out the hole a bit more, then sealing it with high density epoxy filler, which I will likewise use to fill the cracks after enlarging them a bit with a grinder. Then I will redrill the hole. In the future when I use the new pivot point, I will crank down on the bolt to stiffen the upper section of blade.

I do see this as a success. Keep in mind the extreme loads on the rudder and it is from a 1990 boat that has been hammered on. I found out yesterday that one of my friends who is an old fella, ex Laser, International 14 skiff sailor, had likewise "fixed" a Laser rudder vertical back in the early 80's. He did it Andy's way.

I have fixed several Laser rudders that hit the beach hard with the rudder down. It blows up at the knot location. These are not a well built foil by any measure. I'm still amazed how durable the old dagger boards are considering the construction.

I think the rudder cracked at both holes because there is more load in a vertical position than in the swept back standard. Not only is it vertical, it is also longer. Both increase the lever moment on the head. I've sailed that boat in similar conditions atleast 10 times with no ill effects in the past to the rudder....

CaptainAhab said:

... In reality the Laser rudder head as designed distributes little of the rudder load to the aluminum side plates. If one was to tighten the bolt as tight as possible, then perhaps the second hole would work without damage ...
....

I think the rudder cracked at both holes because there is more load in a vertical position than in the swept back standard. Not only is it vertical, it is also longer. Both increase the lever moment on the head ...

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Have you given any thought into drilling the rudder head to accept a second rudder bolt? With both tightened the force would be distributed across the whole rudder head. No kickup possible but ...

I'm really thinking that we need a supplier to consider making a proper rudder that fits the stock rudder head. For example, something like this Albacore elliptical rudder blade ...

I'm considering filling the cracks and then epoxing a skin of biaxial fibreglass on both sides of the head. There is atleast 3-4mm slop in the rudder head. There is plenty of space for the glass and it will never break. Obviously this would make not class legal. I really liked how it performed in the vertical position. I suspect it might not have broken unless it was used in 30-40knot winds. Between my 200lbs and the waves I was pushing the boat pretty much to its theoretical limit before something might break.

I made my old wooden rudder vertical by cutting a slot into the leading edge so it can pivot further forward, like Andy's original.
I was out today for a while in 12 gusting maybe 20, 165lb sailor under radial sail.

It's a HUGE reduction in control force (pressure on the tiller), weather helm, rooster tail wake, and tendency to cavitate/stall. Overall it felt to me like much better control, much more nimble, and FELT like it was faster especially when the boat got hit by a gust + came up on the rail.

I LIKE it. Thanks for the tip Andy.

cskudder said:

It's a HUGE reduction in control force (pressure on the tiller), weather helm, rooster tail wake, and tendency to cavitate/stall. Overall it felt to me like much better control, much more nimble, and FELT like it was faster especially when the boat got hit by a gust + came up on the rail. I LIKE it.

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I could not have described it better myself. Welcome to the Laser Rebels club!

In fact, I've been working on getting a hold of an even cleaner, high aspect ratio rudder. See the photo below. The girls on SCA owed me a couple of favors so here they are in the process of handing over one of their spare rudders as I approach in my Rib to take delivery of the Ill Gotten Booty.



Now I just need to figure out how to mount the SCA's spare to the stern of my Laser.

- Andy