Hello Duncan
Good to hear from you, the advice from Roy cannot be faulted, the sheets should go to the boom ends via the most central and direct route. The three on Inga, one from the transom to Mizzen boom, through the cabin roof to Main boom and forward to foresail all central to deck. Not particularly pretty but has to be.
Can I suggest you obtain a copy of Nylett BB3 "how to" a most brilliant brochure describing all you need to know about all aspects of sails, setting them up, tuning them all for a give away
£7.50 when I bought mine. If for any reason you cannot get a copy feel free to contact me I maybe can help.
The build by mturpin MTINGA 1V shows a great below deck sail control system, well worth checking out.
Take care ChrisG

Hello Len
Thanks for your observation and you could well be correct, I will buy a suitable brass prop when I am sure of the size it needs but she will be for the most part a sailing ship with an effective get me hope method. Thanks for the interest ChrisG

Not a criticism but just an observation, the prop looks a little small. Len

Chris a good afternoon
Of you Need a sleeping medicine for your Little nap let me know and i will sent you some😂

I'm trying to work out where to drill holes for the sail sheets (ropes) in the deck to control the sails on the Bruma kit that I'm trying to modify to also be a sailing boat. I thought this was a good idea before starting the planking so I can see better where everything will go! I'll be interested to see how you are planning to control the various sails. Again I thought I would plan the location of motor, servos and winch before planking - again so I can get a better view! Recently I've been building the cabin top which needed a combination of varnish and white painted coach roofs. It all takes time waiting for the various layers to dry! Need to waterproof the frames before planking.
I cut an extra hole in the stern bulkhead because from someone else's comment , otherwise there isn't enough space for the rudder arm to move fully! So I agree with you about planning - even on a kit! 😊

Hi Chris no need to chastise yourself! You have been through a learning curve and come out the other side having assimilated much of what you need to know.

Actually doing and asking is a good way of learning rather than just reading about it.
If you get the chance of getting on and helping to sail a yacht, not a dinghy you will learn a lot more.
regards
Roy

Hi Duncan. The holes or tubes from the deck should be placed as close to underneath where the sheet connects with the sailboom.
This ensures that the sails all go out at the same angle.

Roy

Wow, Chris . That looks superb!

Hello Alessandro,
I did think it looked like a beached dolphin not a sight I would wish to see I should add.
I have always wanted to build a large model J class yacht and some years ago, after a discussion with another contributor Roy on this site decided one it was too large for me to manage and too costly to build. I particularly liked Tommy Sopwiths Endeavour so for my build I have pinched his colour scheme for her and glad you like it as I do. All the best ChrisG

Hi ChrisG.

The definition of beached dolphin made me laugh.

I really like the colors you chose.

Is it your customization or are they the original ones?

In any case, you did a really good job.

I thought when I started to read Roycv post that he was about to suggest we had a whip round to get a few quid in the kitty to make an offer for the real Inga1V and have it as a club yacht, I then realised it was to remind all interested what a beautiful yacht she is.
Thanks Roy although I am tempted to stray from the plan and attempt a changed topsides, not sure yet but many thanks ChrisG

Hi all this is the full size Inga IV may still be for sale. If you want authentic detail look at the photos.
Might be a good idea before committing to the model plans.
regards
Roy

https://www.facebook.com/profile.php?id=100048676124076

Looking good, well done 👏

Looking good but that is only to be expected from yourself. Well done!
Cheers Duncan 😊

Hi Chris.

I follow your progress with interest and curiosity.

Accompanying written explanations with images is an excellent thing, which makes me understand well what you are doing. Thank you.

Hello Michael
Yes the plan does give a waterline, I have 6kg of ballast in a variety of types all clean lead. I am hoping to resin 4kg low down in the central bilge areas. I have also acquired 2kg of lead shot in 1kg bags that I will be able to place where needed and will be movable now and in the future.
Any information that you come up with will be useful and will help me and others who decide to build one of these beauties in the future.
I plan to fit the prop shaft next as it impacts a lot on the lower hull and where all the ballast needs to fit.
Thanks so much for the help ChrisG

Hi Chris I will weigh my hull as soon as I get chance and then put it in my test tank hopefully then take some pictures and maybe take some measurements,
As long as you leave space in the hull ballast can be added later when you can do a bath test, I'm sure the plan gives a water line

«Entia non sunt multiplicanda praeter necessitatem.»

«Frustra fit per plura quod fieri potest per pauciora.»

Ahahahah.

Stand easy Capt. Roy,
Congratulations, you have, through your determined efforts and exemplary application of Occam's Razor, achieved the 8th electron shell of the quantum dimension and have earned a Mention In Despatches and the right to learn the ultimate answer to the universe and everything (including the empirical method of determining ballast required for a model boat or ship).
The answer being (of course🙄) "forty-two". AKA: Rule of thumb or Suck it and see!😁

@ChrisG, Alessandro, and any other interested parties, see next post on this thread!
Same time same channel😁

😎

Hi Chris, I enjoyed reading their jokey posts.

Hello Alessandro

Thanks for your kind concern I do believe or hope that most of the "gobble de gook" in the most recent blogs from Roy luckyduck and our esteemed fleet admiral are a tongue in cheek way that the British have of " having a laugh". The build is coming along fine despite all of the verbal nonsense.
I think I am wise enough to know when someone is taking the wee wee.
Thank you again for your concern and I hope Google translates this well for you.
Very best regards ChrisG

Hi Doug and Roy.

It's already difficult for me to translate and understand simple and common things, but if you use big protoalactic words I get lost, ahahahahahah!
She seemed like the "supecazzola" from the movie "Amici Miei".

Chris worked hard and fervently, but not anymore.

Joking aside, I don't want to have the opposite effect and instead of helping Chris with his work we slow him down and create even more confusion for him.

The discussion of Roy's prismatic coefficient is certainly not a solution to be discarded, but precisely because Roy (now the godfather of this construction) has already built the model he can provide all the data to Chris.
If I understand correctly, it is the same model and the same dimensions.
If I misunderstood, stop me immediately.
Again, if I understand correctly, Roy suggests obtaining the immersed volume by applying the inverse formula of the prismatic coefficient.
The data to know are, in fact, the prismatic coefficient and the volume of the prism. It would be enough for Roy to provide them to Chris and we could see if it is a reliable result.
Immersed volume = volume of the prism X prismatic coefficient.
The only doubt is whether it can be applied to keels that are not parallel but oblique, I don't know.

I don't know the prismatic coefficient of the Inga1V but for fun I calculated that of my model.
I don't want to "clog up" Chris's topics with other images that don't fit with his construction so I'll report the details on my topic.
I can say that to calculate the immersed volume I applied another method.

Chris, any theoretical calculation needs feedback in the water, in my opinion.
Wanting to use logic, then I tell you to do the test in the water directly, but after having well waterproofed the hull and drawn your waterline.

Fleet Admiral, Sir!

I have feared the Helsenburg Uncertainty Principle has indeed reached its half life and my coefficients have also followed the same path.
I can no longer with any certainty, due to as you say, refractive angular distortion, maintain my past Certainties and fear a fractious disintergration of my own Block Coefficient as a consequence.

Distortions in my data storage elements have created a dichotomy of Certainty within the Uncertainty principle in Helsenberg's theory.

This has caused differing elements within my own coefficients to distort and delineate my perception of data as received.

Consequently any non-specific and distant contact with unspecified or uncertain data will contain an element of predictable uncertainty.

I have as a consequence retained my "Rule of Thumb" and my "That's about right" mantra to enable me to maintain a sedentary life in my armchair!

Uncertainly Yours

Roy

Dear Roy,Also useful stuff, at least interesting.
But I feel you may have overlooked the dilithium half-life degradation coefficient of the data storage elements, which can dramatically affects the distortion ratio of the output Block Coefficient data.
Agreed Prismatic coefficient CAN be more accurate; depending on the prevailing atmospheric conditions and resultant refractive angular distortion and tropospheric scattering.
All of this is, of course, subject to Heisenberg's Uncertainty Principle which renders any such calculation invalid except for a specific moment in time, and pre-supposing you are not directly looking at the test object at that precise moment of measurement!

😎

Hi Luckyduck, all usefuls stuff. One of the first (and few) computer programmes I wrote back in 1967/8 was a printout of look up tables for model boats and yachts, by size and type.
Back then the computer had a room of its own and had individual transistors in the circuit boards.

I read an English University Press (EUP) book called teach your self Naval Architecture. It is easy to understand and is nice and basic.

What you have got is the block coeffecient calculations, if you have access to the centre under water bulkhead area you can get a slightly more accurate answer using the Prismatic coefficient. Yachts fall into a bit less than 0.5 to 0,55.

Don't be put off by the long words, it is a good read that is useful. For model yachts a very old book on model yachts by Colonel Bowden gives a lot of insight.
However do not get caught up in his circular arc ideas they are not at all effective. But I do use his CLR and C of E ideas and his in / out wedge balancing of the volume of the hull comparing being upright and heeled over..

At the end of the day if you find a drawing of a hull that is what you want go for it!

Incidently and perhaps it might suit some older forum members I find using good old fashioned fractions is more convenient than more usual decimal ones.

Once you have your head around fractions they are also quicker and simpler to use. I suppose this is for mental arithmetic and not the calculator!

Roy

Chris
I have been trying to do the same calculations, and found this formula which might help. It is based apparently on full navla architects calculations:
simple formula to determine the estimated all-up weight of a model:-

Displacement formula

When:-
A = length* between stem and stern perpendiculars at plan waterline
B = moulded breadth*
C = draft*
D = displacement in kilogrammes
Y= multiplier**
* in decimetres
** ‘Y’ is a ‘guestimate, which assumes that the underwater volume of the immersed hull is not constant throughout its entire length, i.e. less water is displaced at the bow (swim) and stern (deadwood) than at midships. I use Y= 0.6 for ‘bathtub’ hulls and Y = 0.5 for yachts or other sleeker craft with their finer underwater lines. By comparision, a square biscuit tin would warrant a multiplier of Y = 1.0

Therefore:-
Displacement (kg) = (A*B*C)*Y

Hi Chris I would not worry too much about the all up weight. Another kilogram will only drop the hull half a centimetre and Inga will not notice it.
As far as dispersing the weight inside the hull I would keep it as central as possible.

If you think of the hull as a dumbell, there all the weight is at the ends, it will have greater inertia to turning, where as if the weight is at the centre she will respond to the rudder much quicker.

Although I have reverse for the motor it is hardly effective if there is any wind but with the motor on forward it can help a lot if the shore is too near and you need to tack.

The biggest drawback with the super structure is that the aft mast is through the cabin that comes off so you have to spend a lot of time to gain access to the insides.

If you fit the quick release type hooks for the shrouds that Bearospace Gary uses it would be much easier.

I expect you have thought of it but I reinforce any where on the deck that has to have a screw thread or eye located. If you use screw-in eyes for the shrouds they look a lot better if you slip a close fitting washer on first.

A freind built the Inga IV yacht using the hull I gave him, would you believe in 4 weeks! He split the cabin in two for ease of access. It was not a great success but a few feet from the bank it was hard to tell.
regards
Roy

Thank you Alessandro for taking the time to send me a long and comprehensive list of suggestions all of which will be helpful, and you are quite correct in your comment that Roy is well qualified to offer advice I think his knowledge of boats large and small would be hard to equal.
Again grazie and buonasera, ChrisG

Hi Chris, I just read your post.

I was about to reply but I saw that Roy posted two replies, which I read.

My intent is to help you, but I must say that you are lucky to have a modeler who has already built the same boat as you, like Roy.
In my opinion he gave you the right directions.
If your models are of the same scale (as I think) follow his instructions.

Consider that he has put on 9 kg. Your design says max 9.5 kg. It's okay not to get as far as allowed. It's okay not to go to the limit especially in the early stages of construction.

I totally agree with Roy, put the ballast as low as possible. Is very important.

I advised you to paint the hull first and then put it in a bathtub, because in this way, you can adjust the trim of the ship before definitively fixing the ballast by resining it. You will avoid unpleasant surprises such as having the model too stern or too bowed.
I remain with this idea.

If you can also add ballast later, do the calculations for 8.5 kg, so don't put all 6 kg available.
For the moment just put 4 or 5 and check the setup.
This cannot ignore drawing, first of all the waterline, it is fundamental.
There is little use in doing a static test in the water if you don't first have your waterline clearly drawn on the hull.
Do you know how to do it?

If your model will displace 8.5 kg instead of 9.5 kg (expected by the designer) you will have greater freeboard (distance between the deck and the waterline roughly).
This is not a bad thing, in fact it is better if you have a good straightening pair anyway.
Roy, in fact, rightly stopped at 9 kg.

If you create the possibility of adding half a kg or a kg later, that's even better. But you have to make sure that this weight can be placed low.

I hope I have been clear and of a little help.


P.S. after your last post, which I had not read before preparing this answer, I add the following:

Don't just put the weight below the waterline it must be as low as possible.
The keel designed in this way also serves that purpose.
The weight in the lower part will do its job better, that is, create a righting thrust as opposed to skidding.
A better weight position will allow you to use less of it for straightening purposes.

Please, waterproof the outside of the hull well with paint before the water test.

Hello Roy and thank you so very much your the help, it is much appreciated and I was hoping I would hear from you.
I am surprised that the original grp hull weighs in at a similar weight to my wooden one and it does make sense of things. Your recommendations seem sound and I shall be referring to them as I proceed.
My initial plan is to resin the inside of the hull and re weigh it before placing around 5kg of ballast low down and along the hull below the waterline and securing the it with more resin.
I will trim the boat in the bath (my wife will really appreciate that) and use movable but secure bags of shot to achieve a final trim when the model is about complete.
I am pleased that you are recovering from your injury and wish you good health, thanks again ChrisG

Hello again Chris. Get as much weight as possible as low as possible. If you use lead shot allowing for the airgaps it comes in as the same weight as steel/iron on an equal volume basis.

You must either support it within the hull (bolts lodged in the lead and firmly fixed to the hull frames) or a glass cloth sheeth around the planking and well up the sides etc to stop it snapping off the hull planking.

Otherwise it may flex the area where the lead keel meets the wooden parts of the hull, eventually leading to a mechanical failure.

Roy

Hello Chris G. Just weighed my Inga in complete sailing order. My one comes in at 9 Kgrms.

When I first had her she had more stuff inside and about another kilogram I would guess.

She sailed nicely then and still does, although a little lighter, so not critical.

Would have done this for you before but I have had a right shoulder injury that stopped me picking her up. Almost fixed now.

I run her on a 7.2 volt 3.3 Ahr battery pack which is less weight than your forecast. The Inga fibre hull is exteremely light I think 900 grams or so, I had a bare hull some time ago since passed on.
Maybe compare the weight of your hull the way she is now to work out actual keel weight.

Good luck your planked hull looks really good.

Roy

Hi Chris.
Certainly! You are absolutely right!
Sorry but I took it for granted.
The model must absolutely not be wet before being well painted.
The wood must be totally waterproof, otherwise it will get ruined and you will make a mess.

Thank you Roy and I agree totally that Inga1V is first and foremost a yacht and the motor is a " get me home " addition to the sails therefore I will probably go for a new and unused 600 that I have and a large carefully placed battery that will also add to ballast if needed, thanks "luckyduck" for that idea.
As for a float test Alessandro, I intend not to float her until their is some protection for the planking whether it be paint or resin and that is yet to be decided. I understand your reservations but the lightness of the planked hull has made me think again thanks for the advice, much appreciated.
Thanks to you all for your interest and help ChrisG

Looking great!😊

Do the plans not give any clue? Even images of the real thing would give you a ball park to work to, then give allowance for all the extra weights of fittings, deck, etc. In my yachts I have also used a far heavier battery than normal, as it is a great way of adding ballast without having to use yet more expensive lead, sorting the battery size and position might also aid your decisions.

Hi Chris.

The work continues as best as possible but why can't you do a test in the water?
In my opinion it is very important.

I don't think it's better to put the ballast first and then the engine.
I would do just the opposite because with the engine you have fewer possibilities of useful positions, while the ballast can be managed as you want as long as it is as low as possible.
Why do you prefer to put the ballast first and then the engine?

When positioning the engine, remember the longitudinal quarter rule.

You absolutely must know the displacement and you can do it either through the data of the real boat, applying the scaling factor, or in the water.
Either inside or outside you have to wet it.
But you have to draw the water line yourself, first of all.

If you want I can provide you with more details, if you need just ask.

Hi Roy.

I also used this trick: a lower voltage to limit the number of turns.
On one model, 1/50 scale, [which I haven't shown so far] I have a 24 volt brushed motor. A beast!
They gave it to me as a gift, it was probably from a truck.
Well on this model I run it at a maximum of 6 volts, even if I did some tests at 12 volts.
But at 12 volts it is too fast for the type of vessel.
It has a non-planing displacement hull.

Hi nice seeing the hull as you build her. Thought you might like to know what motor my one has.
Being a yacht hull she does not need much power to drive her along.

I use a Monoperm super with a 1 : 2 gear reduction and a large prop. Power is very modest and you will need no more than 10 Watts of power.

You might consider a 12 volt or higher voltage largish motor but running on a lower voltage battery. As an example a 20 volt motor running on 6 volts will turn a large prop and you do not need a gearbox.

You can run on a much lower voltage even down to 2 or 3 volts (1 liPo).
An esc will run such a motor at a low voltage if you disconnect the red servo lead from the esc but you will need to have a separate Rx battery.

Regards
Roy

That looks really good Chris, an achievement to be proud of

Amazing job, so far👍

Thank you
I will take account of all of your recommendations and it seems that smooth surfaces would seem to be paramount. I am a long way from masts and rigging but a great deal of the pleasure of this type of build is the planning and I am sure you all would agree so I will keep all of this advice for the future.
Many thanks and best regards ChrisG

Hi Chris as we discussed the method you have suggested will work provided you make sure the grooves are properly smoothed before gluing together, I would suggest you apply Ronseal wood hardener to the groves then smooth with at least 600 grit wet and dry before gluing together, then make a scraper that is the profile of the groove so you can drag it through the groove after initial gluing to ensure there isn't any glue left in the groove.

Chris - the inside of the sail groove needs to be as smooth as possible, as the outer edge of the groove. Sail cloth does not like any rough edges of any sort, and it will only take a couple of sailings in windy weather, and the sail material will start to wear away. You almost need a 400 grit finish on anywhere the sail will rub.

I should have added that the mast pieces in the kit are, each mast in 2 pieces. They are divided down the centre line of the yacht. With a groove in each side with the major part of the mast aft and solid. So that both parts are similar.

Hope this helps.
Roy

Hello Chris, just a few days ago I was tweeking the sails in my Inga IV. The gap needs to be about 1mm and the sails need to have a rope or wire inserted in a seem which goes inside the mast. This allows for a loose fit and the wire or rope retains the sail in place.

If you had gone for a groovy ally mast then the sail edge that is located adjacent to the mast is best fitted with a series of plastic tubes about an inch long every couple of inches.
In both cases this allows for the sail to set with the wind.

If the sail is inserted into the small gap in your picture it will hold the material firmly and the sail will have to bend as it comes free of the mast.
My very first mast was like this, it did not work!

The sail had a bend in it going the wrong way. I made a new one which works OK.

regards
Roy

Chris it's looking very good, don't knock your methods, it's the end result that's important to you, it's your model so if you like it then it's great.
Cheers Colin.

Hello Michael and Duncan
Thanks for the kind words they are appreciated I would just like to have achieved a much better level of finish instead of having to rely on my friend P38. In the end I expect the model to look good and maybe even sail well but the "the old man" who built boats when they were works of art did it without P38 just a bit of caulking.
I am not going to beat myself up but just want my modelling friends on this great site to understand that I recognise my shortcomings.
After that confession I will really enjoy proceeding with the build.
Enjoy your evening ChrisG

That's looking really good Chris I'm sure you got a lot of satisfaction from that method and the result looking so good.

Looking really great. You must now have a great deal of satisfaction from what you have achieved. Sit back and admire your achievement so far. Well done! 😊

Hi ChrisG.

I am very pleased and happy that in the Chris Vs PC battle, you won, ahahahah,
but remember that the war with PCs is long, this is just one battle! Ahahahah.
thanks for the photos.

Sorry ChrisG, I couldn't find the photo and then I forgot about it.
Now I will re-edit the message and insert it.
But you are right to choose your favorites, if you already have them.
I'm not an expert and I'm not good at painting but I also prefer Humbrol. Now, however, in the European community the old Humbrols, which were exceptional, are banned, only warehouse remnants can be found. The new Humbrols are not the same.

I'm glad you love Rome, I'm also a lover of Rome.
As a history enthusiast in general and Roman and medieval history in particular, I have also read a lot about the history of your great nation. It has always fascinated me.
I already visited London years ago with my wife and son but I would like to return to visit other places in the United Kingdom.

Hello Alessandro
The photo I have not received but no matter like you I have my favourites. On this build I will probably use spray can primer and then Humbrol which I am a fan of, with a good brush and a good surface the finish if all goes well is fabulous.
I envy you living in Italy and especially one of my favourite cities to visit, Rome I just love your country.
All the best ChrisG

Hi ChrisG.

I used this paint here in the photo and I liked it, but there are many similar ones on the market. It is not worth saving on paint.
In my opinion you are right not to resin on the outside if you are not absolutely sure.
Don't worry, I'll translate, so I'll try to improve my English.

Hello Alessandro
Thank you for this and your previous comments and the plank bending tool you recommended I have but it was not helpful in this application.
Like you I am scared of resin for the final finish and am scared of messing up lots of hours of effort so I also use lots of coats of paint and am generally pleased with the finish.
As for the downhill I am not sure of that, there is more work ahead of me than behind me but as winter approaches it will ensure I have a stimulating and busy winter period.
I thank you for your interest and apologise for not translating for you but my computer skills are more limited than yours so I hope you can do it on receipt.
Photos will follow when I have tidied up a bit, it is chaos in my workroom with such a monster on the bench 🤣🤣
Best regards ChrisG

Hi CrisG.

You must have put in a lot of effort, but it deserves to be seen.
Why don't you post some photos? I'd like to see them.

As for the resin, I totally agree with putting it inside the hull. In fact, the resin waterproofs and makes the hull very resilient.

I don't put it outside because I'm scared.
Not being good, I'm afraid of making a mess.
Outside I only rely on many coats of paints and enamels.

However, once you have passed the hull you are now downhill.

talian-English translation from Google