Did a dream got shattered?

If the designer do the reduction, no problem, if you do it your GM will change dramatically, so you will have to find a way to get back to the original GM.
And you will have of course to re-do the weight assessement and moment.
And you will have to check the roll period and acceleration to be sure to be in tune with the intended number on the original boat and the new boat.
About copyright, be just polite with the designer, dead or alive, and do not still the design, internet or not.
It is just to be honest. No lawyer needed to be elegant.
Good luck
Daniel

 

I was making an observation. You need to come back to earth, mythbusters has more entertaining things to do than to build a design modified by you.
The main reason you are getting insulted (I think) is because the design is absolutely horrid to look at. Why not find a better design?

 

This is the base of your problem I think.
If you know what calculation to do you will be not here in the forum asking for help.
Please don't take that personaly, it is just the reality.
I certainly do not know to do things you know how to do, and "vice and versa"
Daniel

 

Thank you very much. Another one to who I could explain my problems without being insulted. Most obliged.


Yes, it has somewhat affected the buoyancy this reduction by 13%. Special after the local Authoryties requested to place sealed pipes in the structure to ensure that the boat stay afloat at all times. I will still have to go back and discuss more details with them.
But your explanation is spot on with the worries I have been struggling with for myself.

I will go back again to the drawing board and see what you have explained, how to implement this in the reduced plan and see whether I can grasp what you try to warn me for. Please, everybody must understand, with electric motors and battery banks many parameters have to checked and double checked. It is not just a smaller sailing boat. We are pioneering here. There are no ready avialable plans for sea going battery/solarpanles/windenergy/electri mortors driven vessel available. The one I like to build.

Thank you very much Murielle. How are the Maeple Leafs doing? Or are you not an Ice-hockey fan?.

When I was young, 11 years old, we were making floating structures with drums and planks and ropes. We braved the busy shipping lanes in Rotterdam harbour and had a ball, but made a nuisanse of us for the ships. But at that age, we very quickly grasped what stability was. I am therefore very carefull to understand and explore all consequences of the 13% reduction before I will build something.

Bert

 

Ok Bert,
I do not have time to go back and find out exactly why you are asking your questions, what the design is (for example you give three designs). If you can provide that information again, that will help. I recollect seeing something about electric propulsion, but is that part of the existing plan or another change you want to make. Please provide a link to the designers site, and other sites where there are images, and discussions about this design and building it.

What I do see is that you are trying to reduce the size of the boat by 13%. But what aspect is it that you MUST reduce? And why? The beam, length, or what? My initial thought is you can just reduce one dimension 13% and not change much else of the fundamental hull design, except to make your keels either heavier and/or deeper to and your rig lower (I presume we are talking about a sailboat...) to maintain at least your overall stability. Keep in mind that making this change might mean other key aspects of the interior, or drive mechaisim, etc will also have to change, and might even not work out at all, but that is outside our ability to judge without the complete set of plans.

Also, if you have done the calculations then share those with us, including the basic lines drawings they are based on. Its easier to judge the data from the origional statiliby curve and the calculated one than to guess based on general terms.

Regarding what seem to be your main questions: Once you change the plan, you can no longer use the designers weights - in your case you need to use less, if you want the boat to float at the same level. Thus you will most have to deepen your keels to maintain overall stability, as opposed to adding weight (but you can move some weight lower too). Putting them at 90 degrees to the hull panels will only decrease your stability, also when heeled. I am not sure what you mean about a center plate - if you mean yet another keel that will add weight (she will sit lower) and resistance (go slower). And you say 'The designer has provided me with all those very fine detailed drawings': do you mean of these options? Why did he supply them? To solve your problem? Then trust him or her.
OK, lets see if you can now provide a helpful reply...

 

No comment.

I can only conclude, that you have never been on the sea. Pl;ease give me the answers on #1
Bert

 

And here we are again.


Peers

do´nt you see that this halfbaked is not here for getting proper advice (as his brother in arms "tugboat").

He is here to get a confirmation of his preconceptions and dreams!

The idiotic claims, that he "calculated", or he "goes back to the drawing board" does by no means go together with his obvious inability of understanding his capabilities.

You are wasting your time mates! (and girls, sorry Murielle )

Richard

 

Apex1, in this case, its kind of like discussing a movie I am watching with my mates as it unfolds... you do not have the full or logical story, but it fun to second guess whats being said and why, and wondering what is coming next, but in this case, we can even influence the plot a bit... but we know almost for sure, the action will take an 'suprising' direction... and we can leave when we get bored or it gets too unrealistic...

 

Well, it was unrealistic from the very beginning!

It started with the kind of propulsion (which does not exist at present) and goes all the way down to a "self designed", "improved", hull.

Those people (we have more of them), are not willing to learn, nor are they able to understand their limits.

Wasted time..............

Regards
Richard

 

Daq , Mark Steele . How can I access the sail/moment calculator from my
home site ? marksteele2010@yahoo.ca

 

Mark, I guess it was a call for me...?
Just click on this link, it should work with any browser:
http://www.wb-sails.fi/news/SailPowerCalc/SailPowerCalc.htm

Once you're on that page you can save it's address for the future by clicking on "Add to favorites" button in your browser.

 

Look, I have understanding that this site is sponsored by designers and boat builders, but that for a professional site, where people can obtain advice, the amount of mental abuse is allowed, indicates to me a kind of un-professionalism.

I showed it to my wife, and we had a good laugh about the mentality shown in some remarks. She knows my education, my limits and capabilities.

Sorry Tugboat, that I drew you into this unpleasant. mental bashing.

In anyway, I agree with my wife, I will never get a straight answer on a very simple question: Can the instability , created by a reduction of 13% be corrected.

Yes ,in this and in that way.
No, for those reasons.

But I am not interested anymore in any of your answers. Like

Boat-building, first-timer design >>>Thread #16 >>>Alan, you scare my customers, don't say that, the truth is never good for business

Bert

 

Fact is Bert, when I gave you a serious reply yesterday,
- asking for more and clearer input to help everyone be able to make better judgements on the stability, and
- gave you a tentative answer to your questions,

and then asked for a serious, straight, reply from you, I did not get a reply from you. Difficult to help you then.

Many many people have told you that it hard to say if a '13% reduction' will create a dangerous situation, mainly because no one has insight into the exact shape of the origional boat and where the center of gravity is in the origional design. You say you have 'done the calcuations' but do not seem able to provide your input, the forumulas you used, and the output. This is the information needed to give you a clear answer.

Also, it is not clear to me, or I think many, what boat you are making calculations for: you give three designs at the start of this thread. Which one is original, which one are your redesigns. Which one are you doing the calucations on.

You need to provide a clear, single problem, based on a clear single design. And it would very much help if we knew better why you want to make this reduction (see my earlier post). If it is just because of towing restrictions, then I was serious that it might be easier for you to get a special towing permit - I suspect you will only be towing the boat two to 4 times a year.

Let your wife read this, and my earlier post (http://www.boatdesign.net/forums/boat-design/did-dream-got-shattered-32801-3.html#post366380) and judge if I was being unreasonable or unhelpful.

Also Murielle provide a very insighful reply, which you said you would take into consideration and go back and consider - what have you done with that input?

I think many get the impression you are not listening to them, in otherwords, they get the feeling you are not respecting their replies, and so you get little respect in return. But because we always hopeful that you will at one point understand, we are good enough people to keep trying, each in our own way, with humor, or clear frustration, or even sometimes anger... just like in the real world when you interact with all sorts of people with different personalities.

 

You hit the nail Grant.

The information provided was less than sufficient, to start with.
Questions why it MUST be this vessel and not one which fits the requirements remained unanswered.

Critical comments on the so called calculations and redesign capabilities have immediately been named unhelpful.

Our Bertie does just not like to listen and especially not when the comments are critical (though constructive).

But he likes to argue a lot! Even obvious jokes like the one he quoted:

are not allowed in his world, he likes a confirmation of his preconceptions.
And thats ALL we are allowed to secrete.

I follow his dreams since quite a while and noticed his reactions.
Apart from the boat in question, the entire dream of a electric propulsion behind, is premature and that was proven by our experts on electric systems several times, but he does´nt like to listen. If he can dream it, he can build it. And if we cannot assist, we are unable, unpolite, destructive or live in the past.

So, folks, please understand some harsh comments in that context.

Regards
Richard

 

Well, now the only thing to do for you is to go on an other forum, ask the same question, refuse to read the answer, or understand them, and have a good laugh with your wife.
Like that you keep your wife and will not built your boat.
I understand why your wife is laughing
Daniel