Hi Stephen, got your PM.

I think a simple version of the cast one is the way to go. The part of the frame in the hull which holds the rudder may have to be adjusted. Is the lowest part usable to pivot the new rudder on?

I would suggest cutting a brass outline of the original one and butting this up to a brass rod which will be a close fit into a tube in the hull and protude for a tiller and servo connection.

I suggested for brass strips, flattening out a 1/8th inch or 3mm diameter brass tube. To do this lightly clamp an end of the tube to a metal clamp. This so that when hammering the tube flat it cannot rotate, which it will try and do.

If you need to drill holes for securing screws do it now. Then place in a vice and file the edges until it falls into two pieces.
Using the brass rod, butt the cut out rudder to it and fashion the cut brass strip around the rod and either side of the rudder. Butting up close to the brass rod and keeping the rudder central.

If you need to have a pivot at the bottom a small length of tube can be soldered onto the rod leaving a hole for a vertical pin.

Position the rudder centrally against the rod and anchor in place with electrical connector crocodile clips, I would remove the plastic covering. Also use similar to hold the brass securing strips flat against the rudder.
I would assemble this until satisfied with the shape and try and fit in place if possible.

When happy, disassemble and clean the brass ready to take solder, use either solder paste or flux everywhere you want to solder. Bring it all together again and clamp up.
Use a 60 watt tinned iron and solder wire to heat it all up and make sure the solder flows around all joints and cools looking shiny. Check that the brass rudder is still centrally located down the rod.

Cool it all down and then go over all the joints with a sharp implement to remove excess solder and then wire wool all over. Don't use a file as it will take just as long to unclog the solder from the file.

Before painting, clean the new rudder unit in meths to de-grease it and then use an etching primer, spray or paint, then the finishing colour.

With a pintle support at the bottom you will need to have a small support that screws into the hull to support the base of the rudder,

If you want to be keen on detail then some small lumps can be stuck on with superglue to represent the sacrificial anodes that the full size ships have. They are grey in colour., do not paint as the bare metal should be in contact with the water to be effective.

If any forum members reads this and finds a step missing please comment. This is the way I make my metal rudders and they are strong, well none have needed repair yet.

Hope this helps
Roy

Alessandro,
I like your idea of a bolt-on rudder extension for sailing. It can be removable for display

Hi Ross, glad I could help.
My intent was just to remind you of this issue, which you know well, to prepare a plan B in time. Maybe an easier rudder replacement if necessary or something else.
Anyway, as I said, I hope you will not have this problem.

Alessandro,

You have a valid point, and thank you for another challenge. I have thought about this. Your test is a very simple and excellent one to be used. I am hoping that as the mass and volume are reduced 13,824 times (24 x 24 x 24), (250 tons reduced to 36 pounds), the rudder area is reduced only 576 times (24 x24). Sail area and wetted surface area are in proportion to rudder area. This just addresses mass volume and area. The scaling of hydrodynamics and aerodynamics is another whole issue.
As you say, the rudders of my 2.5 kilogram boats are about a third of the area of the 17 kilogram boat's rudder. 3 times the rudder area to control 6 times the weight. In defence, the tiny racing boats can turn almost in their own length. I don't expect that response from the schooner. Thank you again for your insight

Hi Ross.

This rudder is beautiful but is it in perfect scale with the original model of the Bluenose, which you are building?
If the answer is yes, then be careful, do some tests first.

As you well know, scale models reduce linear measures, but the surfaces are reduced to the square (and the volumes to the cube but for now it does not concern us).
This implies that the surfaces of the rudders are reduced with a scale factor to the square, and consequently they may not be as effective as the original ones.
I already discussed this issue with JockScott.
The higher the scale [model smaller than the original] the more incisive the "scale factor" will be. I hope that your model (being very large) will not be affected too much.

It is clear that the problem does not concern motor ship models but only sailing ones.

From direct and indirect experience I can assure you that this actually affects the effectiveness of the rudder.
I have seen that all the modelers who reproduce galleons and vessels to perfection, when they want to make them sail, have to add "prostheses" (usually made of plastic or similar transparent material) to the original rudders. These "prostheses" actually create rudders with much larger surfaces (at least twenty times but even more).
Otherwise (without prostheses) they would not be able to turn (at least not in times and distances acceptable for us).
Many overcome the problem with speed (relatively the fluid is made to flow on the rudder). You can't because you don't have a propeller.

I am optimistic anyway because the galleons have a flat transom. You have a streamlined shape and the keel should favor the fluid fillets that reach the rudder. This gives me hope but I am not exactly one hundred percent sure.

As soon as you can you should do some tests.
I have one in mind, but you with your genius will be able to find others.
Manually push the hull (once waterproofed) with all your strength from the shore towards the center of the lake. At the same time, activate the rudder control either all the way to the right or all the way to the left.
If the model responds then everything is ok, you are sure that the rudder is effective and you can do other tests gradually reducing the manual push to understand empirically, roughly, at what speed it still works.
If it does not turn then you need to think of a solution such as, for example, oversizing the rudder or using a removable prosthesis/extension (to be removed when the model is on static display).

For the rest, thanks to everyone for the advice you gave Stephen, I also benefited from it.

brass strips

I found sheets of brass and cut strips with a box cutter, yes really!😮

Looks Good!
Ifyou need thin brass strips I found that hammering a thin wall brass tube flat and then filing the edges released two nice strips of brass. If you pre-drill them first you can have similar hole fixing.
Roy

This is how I did mine. It has NOT been tested yet

brass rod pins
brass tube pin receivers
brass strips soldered to pins

strips are bolted to rudder and hull (soon)

Hi Stephen this looks like a metalwark job. Are you OK with soldering?
Roy

Hi Marty,
"White metal is about the cheesiest material one could use for a component."👍

Yep. You might actually be better off using a really hard cheese, like a rife Parmesan or Parmigiano Reggiano.😁😋

😎

this is the casting that has failed as you can see it is very soft whitemetal

White metal is about the cheesiest material one could use for a component, like a rudder, that will experience strain. roycv is exactly right: make your own, wood or brass.
-Marty-

Hi Stephen, do you want to know how to make your own rudder?
If you do, post a picture of the rudder type including if it is also located at its base or just 'pokes out'.

I always make my own, either wood or brass.
What are you best at solder or glue?
Roy