Displacement software

And again you're missing the point.
Too bad.

 

Any decent mechanical CAD package will give you the mass and CoG of the parts you have entered, be it a boat or a full plant. Recomputing the waterline should be easy for any marine design software or add on.

The very big main problem is that you have to enter ALL the part in the system without missing one. You do it with a pencil, a spreadsheet, or with the CAD program is equally painfull I fear ...

 

Martijn

Ditto...and never the twain shall meet.

 

I fear thats only true to some extend, and not worth trying for a pro!



Gonzo

try Freeship+ to play around a bit. It is extremely easy to learn, and you will soon find out if it fits your needs.
You then can purchase the delftship programme which has some advantage over the free Freeship+ and does´nt cost the world.
You are professional enough to know what such a program can do for you and what it can´t.
Proper design of course has nothing to do with any software, but you are not the one who must learn that. (and some others will never)

Regards
Richard

 

Gonzo
Delftship is available as a free download usually available from here:
http://www.delftship.net/

HOWEVER THE SITE IS STILL DEAD (Martijn are you aware of this?)

Delftship Pro gives a bit more functionality. The cost is really no more than a small donation when you consider the power of the package.

It can be a little frustrating getting to understand how to work with surfaces but typically after 40 hours of reasonable effort it can be mastered to great satisfaction.

Rick W

 

I don't need a computer to have common sense for me. Ad Hoc is being rather snooty. I will give some of those programs a try and then start the questions on how to make them work
Thanks,

 

Use the link I provided, go straight to the last side and DL the two .pdf files, the rest is a piece of cake for you, believe me.
Ad Hoc has some reason to be a bit hmm, ja, snotty. There are members around here still believing, that their Playstation can replace the knowledge earned by a proper education. That battle will continue, I´m sure.

Regards
Richard

 

I am asking for a specific solution to an aspect of design. He seems to think that calculating what happens when you change a heavy part is not designing. That would rule out all the major Naval design firms that use tank testing and shuflle stuff around to see what happens.

 

Wow. Things really took a nasty turn here.

I suspect we can probably all agree that, unless you're a software engineer, the computer program is not the design- it is just a tool. A tool that, in good hands and with its outputs properly interpreted, can speed up some otherwise tedious parts of the design process.

And, just as you would end up with an expensive disaster if you put a young teenager at the controls of a hydraulic excavator, you'll end up with a heap of worthless data if you put someone at a CAD workstation without first making sure that they know what they're doing.

CAD automates some of the tedious parts of manual drafting. It does not, and cannot, replace knowledge, understanding and sound engineering judgement.

And Gonzo, since you've made it quite clear over the last few years that you do seem to know what you're doing, you will likely have few difficulties automating some of your calculations with a basic marine CAD system like Delftship/Freeship. There's a bit of a learning curve to get used to working directly in 3D, but it all becomes second nature quite quickly if you already know what you're trying to end up with. Being able to see your CB, curve of areas, curvature plots, etc. update in real-time is quite a nice change after drawing by hand for a while.

Rick- Just wondering, have the prices for Delftship Pro come down? Because it was a loooong way from affordable the last time I checked.

 

Matt
it is about 150$ or so, when I recall well. Thats next to nothing.

Gonzo
the reason I was recommending Freeship+ to start with, is simply that it has more features than the free version of Delftship.
And due to the fact that it basically is the same programme you have no problem to switch to Delftship Pro when you decide to purchase th full version later. The Pro has some features Freeship has´nt.
Sure there are others like Maxsurf Rhino and so on. All are way too expensive and much steeper a learn curve than Freeship / Delftship to test just a bit.

A last word to John (Ad hoc), I assume he does´nt know Gonzo is not a novice.

Regards
Richard

 

Mat
When I made my donation the basic Pro was EUR120.

It looks like Martijn is fixing the site now so still cannot confirm if this is the case. Some of the add ons I consider quite expensive but I only have the basic Pro primarily so I could export the different formats. It was also a means of showing appreciation for a great little program.

Rick

 

gonzo
"..He seems to think that calculating what happens when you change a heavy part is not designing.."

Where do I say that??

You first asked:
"..Is there softwere where I can input the offsets and then the weight of building materials and will give me the waterline? Then I could change things like engines or tanks and it recalculates the waterline.."

my reply:
"..Once you have a set of hydro's for your hull, you know where the KB and LCB etc are, then all you need to establish is the distance from the LCB to the LCG, you have a lever, then you ahve the displacement, then look at the hydro's for the MCT 1cm...and so on..."

Which I further elaborated:
"..With a set of hydrostatics, with the current GA and layout, the weights and centres will have been done. If the trim is wrong, after plugging through the hydro's, then all one is looking for, is the total tonne.metre moment...If the total tm is say 100, then this means moving, for example 10tonne 10m, can this be done in the design?...if the total displacement is say 25tonne and the boat is say 20m with an engine say 5tonne, then clearly no, since this would mean moving the engine 20m. As a crude example. One doesn't need to "play" to design, one needs to understand what 'design' is!.."

How does moving "items" about in a program to find the waterline and having several new positions (after trial and error) automatically update the final data constitute design?..this is iterative and just indicates one is not designing, one is being reactive. Because ones does not understand what is required to find the solution to the problem.

It seems, if as Richard says, your not a novice, then you're missing the point.

Matt didn't, he understood perfectly:
"..I suspect we can probably all agree that, unless you're a software engineer, the computer program is not the design- it is just a tool..."

A computer just makes the process quicker. It doesn't design for you...if you start with a mess and don't know what to do, you'll just end up with a mess a whole lot quicker!

 

If I manage to not understand like Herreshoff, Stephens and Frers don't understand, I can live with it. Also, if you don't have answerd to my question, please stay out of my thread. Whether what I do is design or not in your opinion is of little importance to me. Your harrassment and interfering I can do without.

 

Gonzo
The Delftship site is up and running again. This link gives some details on the free version:
http://www.delftship.net/delftship/index.php?option=com_content&view=article&id=31&Itemid=4
You need to create a log in to download. There is no obligation associated with logging in. It allows you to participate on the site board.

Rick W

 

Delftship Pro core looks to be 178.50 euro now (about $250-$300 CDN), small change to a company or a pro designer, but quite a hit for those of us who are students or don't use the software in a professional capacity. Add a few of the extensions and it can really add up. I know Martijn has a great piece of code here- I use the older, open source version myself- but he's apparently aiming it at the professional market now, which makes it hard to justify for those of us who don't get paid for our designs. (A student licence of Rhino is only $200, by comparison; add rhinomarine/orca3d and you're up to $400 as a student- for what is overall a much more versatile program. Commercial licences are obviously much more pricey, so for a design house that only does boats, Delftship Pro might make a lot of sense.)

AH - yes, I do get what you're saying, but I also get what Gonzo's saying- and I don't see why the two of you are in such a huff over this. All that Gonzo's asking for is a tool that can automate the hydrostatics and weights/moments calculations for him, so he doesn't have to slave away with calculator and planimeter every time he wants to change something. And all AH is saying is that you can't just drag stuff around and expect it to eventually work, you have to look at your calculations and interpret them correctly in order to figure out what needs to be done to achieve the desired result. I know both of you know all of this....