Modified Roberts Rudder

[lewsea]

Hi all.

I raised this topic a few month ago about modifying the rudder on my Roberts Mauritious. I have just completed the modification and for those who are interested the job took about a week not counting paint and I am pleased to anounce it was a total success. The performance and steering characteristics improvement is quite amaizing.

The job involved making a new rudder and rudder tube, seals and bearings.

Anyone who's interested I''ll pass on any info email- lewhoneAThotmail.com (the AT is @)

[MMNETSEA]

I note that you have closed the gap between the top of the rudder and the hull. In the old design the amount of water flowing through that space must have contributed to poor rudder control.

The closing of that space will make a significant difference.

Also the extension of the keel (bottom of skeg) to support the rudder has opened the gap between the prop and the Rudder stock - improving the prop efficiency - AND the extension helps in keeping ropes and lines from fouling.

Altogether a great job !!!

[linnupesa]

Originally Posted by lewsea

Hi all.

I raised this topic a few month ago about modifying the rudder on my Roberts Mauritious. I have just completed the modification and for those who are interested the job took about a week not counting paint and I am pleased to anounce it was a total success. The performance and steering characteristics improvement is quite amaizing.

The job involved making a new rudder and rudder tube, seals and bearings.

Anyone who's interested I''ll pass on any info email- lewhoneAThotmail.com (the AT is @)

Hi Lewsea

it looks like you did a splendid job on that rudder. My BR has a very similar hull and doing the mod is

something I've looked at as well, but do not really know if it is worth all the effort time wise. The mod would

mean quite a bit of lazarette modification and one thing tends to lead to another. It's that slippery slope law

that bites you in the tush. Besides, many boatyards do not let you do your own below waterline work. ( why

would you want to pull a boat out of the water in the first place, huh? Duh! )

Could you mail me the jpgs plus others so I can see some more detail? The thumbnails don't seem to blow up

for me on my machine/software, but I did not yet try very much. I have a grp hull but suspect that

yours is welded?

Saw an Oz article on a similar steel-hull mod once. The bloke did it himself with a few days

work and a buddy helper. Of course, in Oz I hear sailors come born with a welder attached to their

umbilical cord and also with a basic supply of baling wire to fix pretty much anything. The owner claimed improved

steering and the cost was really minimal. In my case, it's not steering but the limited space makes a

a folding prop almost impossible. Plus, I do think prop efficiency and reduced turbulence might

be a benefit as well.

Like you I'm also at notmail, but under teknetcal at notmail, to twist a word a bit.

Thanks,

Ivo

[linnupesa]

Originally Posted by lewsea

Hi all.

I raised this topic a few month ago about modifying the rudder on my Roberts Mauritious. I have just completed the modification and for those who are interested the job took about a week not counting paint and I am pleased to anounce it was a total success. The performance and steering characteristics improvement is quite amaizing.

The job involved making a new rudder and rudder tube, seals and bearings.

Anyone who's interested I''ll pass on any info email- lewhoneAThotmail.com (the AT is @)

OK, finally I got the little hamster in the treadmill to churn out a blow-up pic... it just took forever for all 44kb/picture

Your hull does look like steel. One mod I would still add is a little notch on the trailing rudder edge to slide a knotted line

under to make it a fail-safe steering option. I've never tried such in real life and do not know if it actually works or is

just a knuckleheaded idea. It did look very cool and eminently doable as well as being cheap and nasty, so why not?

Ivo

[lewsea]

Originally Posted by linnupesa

Hi Lewsea

it looks like you did a splendid job on that rudder. My BR has a very similar hull and doing the mod is

something I've looked at as well, but do not really know if it is worth all the effort time wise. The mod would

mean quite a bit of lazarette modification and one thing tends to lead to another. It's that slippery slope law

that bites you in the tush. Besides, many boatyards do not let you do your own below waterline work. ( why

would you want to pull a boat out of the water in the first place, huh? Duh! )

Could you mail me the jpgs plus others so I can see some more detail? The thumbnails don't seem to blow up

for me on my machine/software, but I did not yet try very much. I have a grp hull but suspect that

yours is welded?

Saw an Oz article on a similar steel-hull mod once. The bloke did it himself with a few days

work and a buddy helper. Of course, in Oz I hear sailors come born with a welder attached to their

umbilical cord and also with a basic supply of baling wire to fix pretty much anything. The owner claimed improved

steering and the cost was really minimal. In my case, it's not steering but the limited space makes a

a folding prop almost impossible. Plus, I do think prop efficiency and reduced turbulence might

be a benefit as well.

Like you I'm also at notmail, but under teknetcal at notmail, to twist a word a bit.

Thanks,

Ivo

Hi Ivo

By changing the angle of the rudder it only moved the rudder stock aft around four inches so there is no need to butcher cabinet work too much,but it moved the bottom of the rudder aft by over one meter the deeper you go the denser the water is. As for the cupboards in my case there are too many in the aft cabin which makes it very cramped so I have removed some and replaced(or in the process of) them with a settee and also widening the bed by 12 inches. It's a shame if you can't do the job yourself. I must admit I quite enjoyed the project and it didn't cost that much, my only grumble was that we had the wetest October in years, about eight inches of rain fell during the job, October is our dry season!

The change has meant that I can ballance the rig and I am getting feed back through the wheel that I never had before so I can feel weather/lee helm also once the rig is balanced I can let go of the wheel and she will hold course. She is a different boat now.

As my BR is steel and yours is glass the photo's probably aren't much use to you but if you want dimensions ect let me know.

Lew

[linnupesa]

Originally Posted by lewsea

Hi Ivo

By changing the angle of the rudder it only moved the rudder stock aft around four inches so there is no need to butcher cabinet work too much,but it moved the bottom of the rudder aft by over one meter the deeper you go the denser the water is. As for the cupboards in my case there are too many in the aft cabin which makes it very cramped so I have removed some and replaced(or in the process of) them with a settee and also widening the bed by 12 inches. It's a shame if you can't do the job yourself. I must admit I quite enjoyed the project and it didn't cost that much, my only grumble was that we had the wetest October in years, about eight inches of rain fell during the job, October is our dry season!

The change has meant that I can ballance the rig and I am getting feed back through the wheel that I never had before so I can feel weather/lee helm also once the rig is balanced I can let go of the wheel and she will hold course. She is a different boat now.

As my BR is steel and yours is glass the photo's probably aren't much use to you but if you want dimensions ect let me know.

Lew

Thanks Lew

The full hull pic shows what you are referring to quite well. On mine the deck is raised from about the prop position,

giving some extra headroom. It seems to me that my engine may be sitting a bit further back than yours but one needs to

actually put the pictures side by side for a true comparison to scale.

On the Island packets the bottom of the rudder is mounted on a skeg and I've often wondered how that would hold up against

violent sideways forces. Having the much beefier extension like you show it would likely be stronger. Moving the rudder back

will increase the leverage moment into I guess THE LEVERAGE moment, so every bit of beef added will help. It still is far

stronger than having just a spade rudder, though that may be very nice in performance and handling. IMHO these are catch-all

devices of extreme efficiency when you least want them to be, like in areas choked with lobster pots.

Perhaps you want to re-post the e-mails between us on notmail, as others may say "huh?" and find the thread a bit disjointed.

Thank you for all the info and congrats on a job nicely done. Too many folks buy off the shelf and forget all the pleasures that

accrue from "simply messing around in boats". ( Hopefully there are no wimmens around to agree with the "messing" part )

Ivo... gotta run now and get going on a hike in this great CA weather

[Silver Raven]

G'day bloke. From up the hill. Am back from Darwin & a tad bit flooded in. GREAT job you did on that rudder modification. So glad it works-at-treat. If your not out sailing drop us all a note as to how it's still working. Very professionally done. good-on-yer, bloke!! Would you take a moment to make some comments to Mike about his desire to sail north in the Cyclone season. Your professional experience should give him more information to better judge the wisdom or otherwise of his proposed voyage. Thanks mate. Ciao, james