Tiller judder

[bizzard]

If the rudder goes hard over in forward and everyting is in the right place as it should be it means the rudder would have more than 50% balance forward of the rudder stock. I know there are boat builders out there that are that stupid but look for another reason.

1.Is the is the rudder stock in it's bottom bearing?

2.Very unlikley to be anything to do with the top bearing.

3.Vibration is there any damage to the propeller you need very little damage to cause vibration in the rudder.

4.If your rudder is damaged you can normally drop the rudder off the boat. Remove the swan neck and upper bearing, put the nut back on, tie a rope to the rudder stock and another through the hole in the rudder tit (yes thats what it is there for it is not decoration) push boat to the middle of the canal lift rudder stock and pull the rudder to one side and let go. the rudder should now be on the bottom of the canal. As long as you have tied the rope on well you can now drag it out of the canal. IMPORTANT LEAVE THE ROPE THAT WAS TIED TO THE RUDDER STOCK IN THE RUDDER TUBE THIS IS THE ONE YOU WILL PULL THE RUDDER BACK UP WITH.

Under forward power the tiller will fling across with no more than %40 leading, as its closer to the prop it gets a more powerful thrust stream.I think the limit is about %30-35,before steering becomes uncomfortable.

The rudder assembly can be remove in that fashion providing its not got a fixed welded tiller,like mine, and that the stock tube is of large enough ID to allow the stock to be jumped sideways off the skeg socket.One has to determine exactly what ones got before attempting it in the water like that.

[H.C.Astell & Co]

If the rudder goes hard over in forward and everyting is in the right place as it should be it means the rudder would have more than 50% balance forward of the rudder stock. I know there are boat builders out there that are that stupid but look for another reason.

1.Is the is the rudder stock in it's bottom bearing?

2.Very unlikley to be anything to do with the top bearing.

3.Vibration is there any damage to the propeller you need very little damage to cause vibration in the rudder.

4.If your rudder is damaged you can normally drop the rudder off the boat. Remove the swan neck and upper bearing, put the nut back on, tie a rope to the rudder stock and another through the hole in the rudder tit (yes thats what it is there for it is not decoration) push boat to the middle of the canal lift rudder stock and pull the rudder to one side and let go. the rudder should now be on the bottom of the canal. As long as you have tied the rope on well you can now drag it out of the canal. IMPORTANT LEAVE THE ROPE THAT WAS TIED TO THE RUDDER STOCK IN THE RUDDER TUBE THIS IS THE ONE YOU WILL PULL THE RUDDER BACK UP WITH.

balance plate should be about 20% of the size of the main plate, is the ratio I've always believed to be 'received wisdom' & it seems to work.

 

There is a certain amount of personal preference involved. I like to be able to feel what's happening & really dislike handling boats with over-balanced rudders.

Some people don't believe there should be any effort involved in moving the tiller

 

Tim

 

 

Under forward power the tiller will fling across with no more than %40 leading, as its closer to the prop it gets a more powerful thrust stream.I think the limit is about %30-35,before steering becomes uncomfortable.

The rudder assembly can be remove in that fashion providing its not got a fixed welded tiller,like mine, and that the stock tube is of large enough ID to allow the stock to be jumped sideways off the skeg socket.One has to determine exactly what ones got before attempting it in the water like that.

 

Fancy popping up to yelvertoft and have a looksee , i would be happy to cover your time and expenses. although being an engineer i have worked on alot of machines, i dont (wont) touch anything i have no knowledge of, and would rather learn from the experienced and part with a few pennies, than get myself in a right ole pickle on the side of the cut.

i will take detailed picture this weekend to help you see if this process indeed can be applied.

 

Kind Regards for taking time to help me, much appreciated

 

Harvey

Edited November 2, 2011 by H.C.Astell & Co

[bizzard]

balance plate should be about 20% of the size of the main plate, is the ratio I've always believed to be 'received wisdom' & it seems to work.

 

There is a certain amount of personal preference involved. I like to be able to feel what's happening & really dislike handling boats with over-balanced rudders.

Some people don't believe there should be any effort involved in moving the tiller

 

Tim

Indeed.At sea an over balanced rudder is highly highly dangerous, motor or and especially under sail.

All sea boat designers and builders are extremely careful about this.

Yes my rudders about %25-75 balance,i prefer more feel and better self centering, too.

[steelaway]

Fancy popping up to yelvertoft and have a looksee , i would be happy to cover your time and expenses. although being an engineer i have worked on alot of machines, i dont (wont) touch anything i have no knowledge of, and would rather learn from the experienced and part with a few pennies, than get myself in a right ole pickle on the side of the cut.

i will take detailed picture this weekend to help you see if this process indeed can be applied.

 

Kind Regards for taking time to help me, much appreciated

 

Harvey

 

 

 

 

Usuall arrangement

 

Alex

 

 

[ditchcrawler]

You will have to have it dry docked to confirm and cure your problems.

You might get a marina to tug it up the slope backward so you can have quick look.

I don't think it will be a problem with the balance blade but you be able to have a look.

 

Alex

Why not. I took 2" off mine and welded a bit on the trailing edge. We also had the same problem on our shared boat, but as it wasn't mine I lived with it. As soon as you let go of the tiller it was hard over which ever way it fancied.

 

If the rudder goes hard over in forward and everyting is in the right place as it should be it means the rudder would have more than 50% balance forward of the rudder stock. I know there are boat builders out there that are that stupid but look for another reason.

1.Is the is the rudder stock in it's bottom bearing?

2.Very unlikley to be anything to do with the top bearing.

3.Vibration is there any damage to the propeller you need very little damage to cause vibration in the rudder.

4.If your rudder is damaged you can normally drop the rudder off the boat. Remove the swan neck and upper bearing, put the nut back on, tie a rope to the rudder stock and another through the hole in the rudder tit (yes thats what it is there for it is not decoration) push boat to the middle of the canal lift rudder stock and pull the rudder to one side and let go. the rudder should now be on the bottom of the canal. As long as you have tied the rope on well you can now drag it out of the canal. IMPORTANT LEAVE THE ROPE THAT WAS TIED TO THE RUDDER STOCK IN THE RUDDER TUBE THIS IS THE ONE YOU WILL PULL THE RUDDER BACK UP WITH.

You don't need anywhere near 50% for that. Lots of new boats have zero weight on the tiller, just watch ladies steer with fingertip effort

[Timleech]

Indeed.At sea an over balanced rudder is highly highly dangerous, motor or and especially under sail.

All sea boat designers and builders are extremely careful about this.

Yes my rudders about %25-75 balance,i prefer more feel and better self centering, too.

 

That would make your balance about 33% of the main blade, if I've understood you correctly, which is more than I would like.

 

Tim

[bizzard]

That would make your balance about 33% of the main blade, if I've understood you correctly, which is more than I would like.

 

Tim

I've not explained clearly. Its %75 main blade and %25 balance.And is ok and self centres reasonably.

[steelaway]

Why not. I took 2" off mine and welded a bit on the trailing edge. We also had the same problem on our shared boat, but as it wasn't mine I lived with it. As soon as you let go of the tiller it was hard over which ever way it fancied.

 

 

You don't need anywhere near 50% for that. Lots of new boats have zero weight on the tiller, just watch ladies steer with fingertip effort

 

 

 

 

I was really pointing to the bottom skeg bearing arrangement. as he is not familiar with the standard construction.

I think that maybe the rudder has been lifted out its socket. He should be able to reach down through the weed hatch to check it

I had 2" added to my leading edge to improve the steering - worked a treat. I also had to add a load of ballast at the very front and that also made a big difference

Different boats, different solutions?

 

Alex

[H.C.Astell & Co]

Usuall arrangement

 

Alex

 

Thanks now i know what to look (feel) for at the weekend

I noticed your trailing edge looks around 10/12mm thick and has some more strength from them ribs, i think mine is alot thinner & lighter as i can turn my boat using my ear hair..

 

 

I was really pointing to the bottom skeg bearing arrangement. as he is not familiar with the standard construction.

I think that maybe the rudder has been lifted out its socket. He should be able to reach down through the weed hatch to check it

I had 2" added to my leading edge to improve the steering - worked a treat. I also had to add a load of ballast at the very front and that also made a big difference

Different boats, different solutions?

 

Alex

I was following this thread well, until you posted that you added 2" to the leading edge to improve stearing , but i thought too much leading edge is the route cause of this type of problem.

Edited November 2, 2011 by H.C.Astell & Co

[bizzard]

Thanks now i know what to look (feel) for at the weekend

I noticed your trailing edge looks around 10/12mm thick and has some more strength from them ribs, i think mine is alot thinner & lighter as i can turn my boat using my ear hair..

 

 

 

I was following this thread well, until you posted that you added 2" to the leading edge to improve stearing , but i thought too much leading edge is the route cause of this type of problem.

It couldn't quite have had enough on the leading edge in the first place unless he likes a tricky negative helm that he daresent let go of.

[PhilR]

I've not explained clearly. Its %75 main blade and %25 balance.And is ok and self centres reasonably.

 

I can understand Tim's confusion. I always thought the leading edge [balance] (in front of the rudder stock) was expressed as a % of the main blade area which is behind the rudder stock.

 

My rudder has about 6 ins leading edge and 22 ins blade behind the rudder stock. Next time it is docked I'll be having 2 or 3 inches trimmed off the leading edge because it refuses to self centre......... but it does steer in reverse ................

Edited November 3, 2011 by PhilR

[bizzard]

I can understand Tim's confusion. I always thought the leading edge [balance] (in front of the rudder stock) was expressed as a % of the main blade area which is behind the rudder stock.

 

My rudder has about 6 ins leading edge and 22 ins blade behind the rudder stock. Next time it is docked I'll be having 2 or 3 inches trimmed off the leading edge because it refuses to self centre......... but it does steer in reverse ................

I'd rather it steered properly going forward as you are going in that direction mostly.

A large balance blade will catch more of the prop wash when reversing,for the bursts of forward to kick the stern round and straighten up.

A very large balance blades ok as long as the trailing piece is correspondingly large to counteract it,but of course it all becomes heavier to handle.

Edited November 3, 2011 by bizzard

[Timleech]

I can understand Tim's confusion. I always thought the leading edge [balance] (in front of the rudder stock) was expressed as a % of the main blade area which is behind the rudder stock.

 

 

That's how I would describe it, & one-fifth (20%) of the main blade area (the area behind the stock) as balance in front of the stock is an often quoted and very workable norm.

 

I've not explained clearly. Its %75 main blade and %25 balance.And is ok and self centres reasonably.

 

That's what I thought you meant. So your balance flight is about 33% of the main blade. More than I would like, but as I said earlier personal preferences do come into this.

 

Tim

[bizzard]

That's how I would describe it, & one-fifth (20%) of the main blade area (the area behind the stock) as balance in front of the stock is an often quoted and very workable norm.

 

 

 

That's what I thought you meant. So your balance flight is about 33% of the main blade. More than I would like, but as I said earlier personal preferences do come into this.

 

Tim

Yes quite so, i do understand Tim,

But i've always found that dealing with the blades as separate percentages easier for folk to understand.

When i taught sailing in my spare time i found this so.Although a sailing boats good rudder handling is mainly down to a well designed boat as a whole,leverage moments in the correct place ''mast sails,rudder shape and size ect.

[steelaway]

Thanks now i know what to look (feel) for at the weekend

I noticed your trailing edge looks around 10/12mm thick and has some more strength from them ribs, i think mine is alot thinner & lighter as i can turn my boat using my ear hair..

 

 

 

I was following this thread well, until you posted that you added 2" to the leading edge to improve stearing , but i thought too much leading edge is the route cause of this type of problem.

 

 

 

 

The leading edge extension was also to counteract the amount of prop wash around the back of the rudder on full lock.

Much of the thrust was being lost around the leading edge.

I've still got a theory that the distance between the prop to the rudder distance being a big factor in a good steering NB

 

Alex

[tosher]

The leading edge extension was also to counteract the amount of prop wash around the back of the rudder on full lock.

Much of the thrust was being lost around the leading edge.

I've still got a theory that the distance between the prop to the rudder distance being a big factor in a good steering NB

 

Alex

 

 

Interesting, that's just what I was told by Crowthers some years ago. Anybody any idea what this measurement should ideally be ?? tosher.

[bottle]

or

 

Is the size of the leading part (which would have an effect on the size of the trailing part) as ratio of the prop size (diameter) be more important?

[NB Esk]

For anyone who thinks the rudder shaft may have lifted out of the bottom skeg bearing & it can't be reached thro' the weedhatch, you can make up a simple viewing scope (sure it has a proper name, but can't think of it) to check.

Obtain a length of plastic drainpipe & fix a piece of glass or clear plastic to one end, sealing with a waterproof adhesive. In use, just head in the direction of the bearing & check it out. If the water's very murky, cable-tie a waterproof torch to the outside...sorted.

 

If it doesn't have a proper name, it's an "ESK-SCOPE"....definately.

[Timleech]

The leading edge extension was also to counteract the amount of prop wash around the back of the rudder on full lock.

Much of the thrust was being lost around the leading edge.

I've still got a theory that the distance between the prop to the rudder distance being a big factor in a good steering NB

 

Alex

 

If a boat has been built with too much space between rudder & propeller, a vertical plate between the two can help - similar to the skeg support which was normal on older working motor boats.

 

Tim

[steelaway]

If a boat has been built with too much space between rudder & propeller, a vertical plate between the two can help - similar to the skeg support which was normal on older working motor boats.

 

Tim

 

 

 

My old Liverpool boat had a good few inches more between the prop and rudder than this one.

I could do tricks with that one that amazed people (forward or reverse) I even frightened one bloke in Preston Dock

This new one, with much less distance, is a comparative camel of a thing, I am used to it now but I can still remember how good it could be.

I'm convinced that the prop wash has to be given time to form a 'slug' of water to push the rudder - not just splash itself aimlessly again the rudder.

This new one also needs a longer swim, its great on rivers where it can collect water from the depth but any thing less and its a slug.

I spent some months this year in the company of a Jonathan Wilson boat (with a14' swim) and it was definitely a better swimming boat than mine.

 

Alex

[Guest]

For anyone who thinks the rudder shaft may have lifted out of the bottom skeg bearing & it can't be reached thro' the weedhatch, you can make up a simple viewing scope (sure it has a proper name, but can't think of it) to check.

Obtain a length of plastic drainpipe & fix a piece of glass or clear plastic to one end, sealing with a waterproof adhesive. In use, just head in the direction of the bearing & check it out. If the water's very murky, cable-tie a waterproof torch to the outside...sorted.

 

If it doesn't have a proper name, it's an "ESK-SCOPE"....definately.

Sorry to pee on your parade, but the correct name for this device is a "CAT SCAN."

[NB Esk]

Sorry to pee on your parade, but the correct name for this device is a "CAT SCAN."

 

shucks....missed out again...

[steelaway]

Sorry to pee on your parade, but the correct name for this device is a "CAT SCAN."

 

You need a spell checker. Its a "SCAT CAN"

 

I've just registered it.

 

Alex

[sheriff]

You need a spell checker. Its a "SCAT CAN"

 

I've just registered it.

 

Alex

[/quo

Edited November 4, 2011 by sheriff

[Alan de Enfield]

Sorry to pee on your parade, but the correct name for this device is a "CAT SCAN."

 

 

A woman brought a very limp duck into a veterinary surgeon. As she laid her pet on the table, the vet pulled out his stethoscope and listened to the bird's chest.

After a moment or two, the vet shook his head sadly and said, "I'm so sorry, your pet has passed away."

The distressed owner wailed, "Are you sure?"

"Yes, I'm sure. The duck is dead," he replied.

"How can you be so sure", she protested. "I mean, you haven't done any testing on him or anything. He might just be in a coma or something."

The vet rolled his eyes, turned around and left the room. He returned a few moments later with a black Labrador.

As the duck's owner looked on in amazement, the dog stood on his hind legs, put his front paws on the examination table and sniffed the duck from top to bottom. He then looked at the vet with sad eyes and shook

his head. The vet patted the dog and took it out and returned a few moments later with a beautiful cat. The cat jumped up on the table and also sniffed the bird from its beak to it's tail and back again. The cat sat back on its haunches, shook its head, meowed softly, jumped down and strolled out of the room.

The vet looked at the woman and said, "I'm sorry, but as I said, this is most definitely, 100% certifiably, a dead duck."

Then the vet turned to his computer terminal, hit a few keys and produced a bill, which he handed to the woman. The duck's owner, still in shock, took the bill.

"£150!" she cried. "£150 just to tell me my duck is dead?!!"

The vet shrugged. "I'm sorry. If you'd taken my word for it, the bill would have been £20. But what with the Lab Report and the Cat Scan, it all adds up."