# Rotating Masts



## rickles23 (Oct 13, 2006)

Hi,
I am building a Chinese Junk to fit the Footy Rules which means the hull is 12 inches long.

It will have two masts but to make the sails work I need to rotate the masts.

The lower part of the masts will be brass tube and I will plug in the rest of the mast complete with sails.

I need a bit of help in deciding which is the best way to make the masts rotate. Any help is welcome...(Thumb)

Regards


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## stores (Apr 8, 2007)

*rotating masts.*

do they rotate on a real junk, ? i thought the sails rotated around a mast on all sailing ships, ?


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## John Rogers (May 11, 2004)

stores said:


> do they rotate on a real junk, ? i thought the sails rotated around a mast on all sailing ships, ?




Good question Stores,I know sails rotate with the sail Boom or Gaff,interesting to know if the mast turns on Junks.

John


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## jerome morris (May 27, 2008)

connect the mast directly to the servo top.


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## Don Matheson (Mar 13, 2007)

If you must do it then Jerome has it right. However if I had to do this I would add a load bearing collar on the mast to keep the weight off the servo. That would give you a good range in turning the mast but I would much rather keep the mast rigid and use the servo to slacken or heave on the sheets thus turning the sail, the wind will do the rest.

Don


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## rickles23 (Oct 13, 2006)

Hi,

Real Junks masts do not rotate but they do have a crew to manage the sails.
On the Footy Junks that I have seen the masts rotate as there is only room for two servos, one for steering.

I know the system works but just cannot visualize it.

Regards


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## stores (Apr 8, 2007)

*rotating mast*

on a real junk, the sail rotates around the mast, same rig as lugsail, but with battens and different shape, wikipedia has all the details. how can u have a rotating mast, ? what about the standing rigging. ?


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## 6639 (Apr 20, 2006)

try asking *regiment* on here rick.......he'll probably be able to help you..........he's a helpfull chappy.
neil.

http://www.modelboatmayhem.co.uk/forum/index.php?topic=29135.0


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## 6639 (Apr 20, 2006)

you guys that keep pointing out the rigs on Junks....we are actually talking of a none scale sailing model here of 12" long (300mm from bow to stern)......I don't think that the format of real junk rig has anything to do with such a small model and how it is actually rigged for sailing purposes,

and as a modeller myself a certain modellers licence is allowed here! I think that Rick is after constructive methods and help of turning his masts to get a small model working on a pond, NOT critisism and comments on how a real junk is rigged, which has absolutely no bearing what so ever on a model that size.

Try the lads on Model boat mayhem Rick, they'll be able to help you.Neil.


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## rickles23 (Oct 13, 2006)

Thank you nhp651,
The Footy class is the smallest class in model yacht racing and one of the most popular.
My main racing yacht is the semi traditional Marblehead. This class has crbon fibre masts and booms as opposed to the wooden masts. She carries 800 square inches of sail and the mast is 6 feet and the hull is 50.5 inches long.
Regards


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## Don Matheson (Mar 13, 2007)

nhp651 I think you will find that on post No. 4 Jerome mentioned how to do it and in post No. 5 I made a suggestion on how to avoid an overload of the servo. So not everyone mentioned a real junk.
My idea, same as Jeromes, would be to use a servo on one mast (I assume rickles is using two) use a load bearing device, both masts, easy to make, on the mast above the deck and link the second mast using a servo arm on mast below the deck and both masts will turn as required. Main point being keep the weight off the servo.

Also a model maker myself, smallest pond boat is a 10" MTB but I am presently trying to find a way to increase the throw of two rudders (out of three) an extra 10% when the vessel goes to full speed. Any ideas welcome as I am a wee bit stumped. Think I have it but not sure so help would be appreciated and gratefully acknowleged as I dont want to build to tanktesting stage to find its a non starter.
Hope the idea of using the servo helps you rickles.

Don


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## rickles23 (Oct 13, 2006)

Hi Don,
On the Footy Junk as with the other styles of Footies there is only room for two servos, one for steering.
But I have taken nhp651 advise and joined Model Boat Mayhem. The beauty of the Footy class is even fully rigged they don't take up much room in the car.
After this one I have a Thames Barge coming from the UK, same size..12 inches.
Regards


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## Don Matheson (Mar 13, 2007)

Rickles, that was what I was trying to explain, one steering servo and a second to work the two masts.
I know what you mean about space in the car, was going to build a Great Laker but couldnt get it in my estate or pickup. Thought of building a box to go on the roof but worried people may think I was doing cut price funerals.
Good luck with your footer, the junk sounds exciting.
I thought Model Boat Mayhem had shut down?

Don


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## 6639 (Apr 20, 2006)

Don Matheson said:


> nhp651 I think you will find that on post No. 4 Jerome mentioned how to do it and in post No. 5 I made a suggestion on how to avoid an overload of the servo. So not everyone mentioned a real junk.
> My idea, same as Jeromes, would be to use a servo on one mast (I assume rickles is using two) use a load bearing device, both masts, easy to make, on the mast above the deck and link the second mast using a servo arm on mast below the deck and both masts will turn as required. Main point being keep the weight off the servo.
> 
> Also a model maker myself, smallest pond boat is a 10" MTB but I am presently trying to find a way to increase the throw of two rudders (out of three) an extra 10% when the vessel goes to full speed. Any ideas welcome as I am a wee bit stumped. Think I have it but not sure so help would be appreciated and gratefully acknowleged as I dont want to build to tanktesting stage to find its a non starter.
> ...


i quite agree don.and wasn't getting at you or anyone for that matter...just stating that there is a difference between a 12" none scale model and a real ship......but not all people can equate to the fact that a sailing model has to be treated tiotally differently to a real ship, in many respects if you want it to sail, and those that point out the vagaries of ships rig with relationship to model rig are totally out of step with modelling reality. i think you would agree with me that on a sailing model, many of the standing and running rigging lines have to be either left off or truncated in order to gain quick access to the interior and also for handling without breaking fine rigging wire, but many a time at the lakeside, mariners of old tell me in no uncertain manner that my rigging plan is wrong...but can't understand or don't want to understand when you try telling them that you simply can't detail that finly on a working model..


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## 6639 (Apr 20, 2006)

as for more throw on your rudders, you could either lengthen the arm on your servo arm keeping rudder arm the same length as the servo arm...thus giving a longer throw, , or you could put an extension onto the rudder when sailing made from clear acrylic so that it doesn't show when under the water........both these methods give a better flow and throw for the rudder.
neil.


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## Don Matheson (Mar 13, 2007)

Didnt think you were getting at me Neil, I was trying, poorly I know, to let Rick and yourself know there were some people who did know the problems of scale and non scale sail. I could understand the two masts single servo and liked Jeromes idea but mast weight could be a problem. I also wondered about one servo using one sheet to each sail take some adjustment to the servo arm but could be done.

My own problem is there will be three rudders but at full speed the Port and Stbd open out another 10 degrees away from straight port one opening out further to port and same for Stbd with the centre rudder staying straight. Think I will need to use a second servo for port and stbd. rudders, that way your first idea would work. Thanks mate.

Don


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## 6639 (Apr 20, 2006)

don't know about that one then, don..you've stumped me.....only ever built one model that worked with twin rudders, but never 3...sorry about that, but if you send me adiagram i'll have a think......i'll pm you my email address.
neil.


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## 6639 (Apr 20, 2006)

Don, your message box is full and it won't allow me to send a pm.
neil.


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## Don Matheson (Mar 13, 2007)

It wasnt completely full and I received a PM from you and just replied to you. Will go and check again.

Don


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## rickles23 (Oct 13, 2006)

Hi Don,
Model Boat Mayhem is alive and well, I joined yesterday.
http://www.modelboatmayhem.co.uk/forum/index.php?board=84.0 is the website.
I think I can visulize what you mean so I shall go looking for a load bearing device.
Regards


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## Don Matheson (Mar 13, 2007)

Rickles The load bearing device is very simple to make or have a frend with a lathe turn one (or two) out for you.
It just needs a small tube with a collar, the tube fits the mast exactly with the collar part of the tube bearing down towards the deck. The loadbearing part can be almost the same in reverse without fitting the mast so tightly but secured on the deck and unable to move. This should be positioned to allow the mast to touch the servo without putting an always changing weight on it. This should allow a much longer servo life.
The second mast can be made to follow by using an arm from the servo with a link to the second mast
Hope this is a help, if not Pm me and I will try harder to explain.
Thanks for the link to MBM.
Don


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## rickles23 (Oct 13, 2006)

Hi all,

Problem solved!

I helped a good friend to make thirty 1/72 scale aircraft for an r/c Japanese aircraft carrier he is making and as we talked I mentioned the rotating mast problem.

In two minutes he had drawn a sketch and said this is what you need to do. 

I don't know how to attach a photograph to this reply but I have PM'd Don.
Regards


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## jerome morris (May 27, 2008)

I love a great ending!


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