Displacement Volume in v4.18

[S . Warr]

I still think that this update is the cat’s whiskers, but I now have a rather significant problem.

The “Design Hydrostatics Report” no longer calculates “Displaced Volume”.

In that my design is of a Box Rule type, this feature is essential to me.

Is there a setting that I need to change, or is this feature no longer available in the updated free version?

PLEASE NOTE: I have changed no setting from earlier file (created in v3.20).

S/F, Phil

[Marven]

Hi Phil,

Displaced volume is now called “Moulded volume”, which is the volume measured to the inside of the shell plating.
The “Total displaced volume” is the moulded volume increased with the wetted surface area multiplied with the mean shell thickness (to account for the extra volume displaced by the shell plating)

[S . Warr]

Marven,

Thank you for the prompt response, but I still can’t get to where I want to go 🙁 .

The box rule dictates a maximum total weight (hull, keel, bulb, rudder, spars, electronics, etc.) of not less than 4.00 tonnes (actually 4.00 kg, but I have scaled up…).

To achieve maximum performance one needs to optimize the shape of the hull and underwater appendages to achieve lightest possible displacement of 4.00 tonnes.

Skin thickness, and weights of build materials, etc., will be selected to meet design displacement (4.00).

I tried entering a (nominal) skin thickness of 3.0 for hull stations, but this had no affect on Hydro Report.

There are still no readings for Moulded Volume (which would appear to be interior volume of hull – a reading of limited value for my design exercise), nor Total Displacement Volume, or Displacement).

To further compound my dilemna, the rudder, keel and bulb will be solid structures with no “skin” thickness

Sorry for the lengthy post, but I’m worried – is it possible to revert to v3.20?

S/F, Phil

[Marven]

Of course you could revert to v3.20, however the same values should still be in your report, possibly displayed under a different name. Can you perhaps post a screenshot of your design hydrostatics view, showing especially the volume properties?

[S . Warr]

Marven,

I have attached relevant data, but also included screen shot for stations showing skin thickness added…

Again, I would like to note that this problem did not arise until after the update. I also tried opening old files (done with v3.20) with no volume data displayed.

S/F, Phil [file name=HSR_100920.doc size=340992]http://delftship.net/delftship/media/kunena/attachments/legacy/files/HSR_100920.doc[/file]

Attachments:

• HSR_100920.doc

[Marven]

The data seems to be missing?

[S . Warr]

Sorry, Marven :ohmy:

File added to original post.

S/F, Phil

[Marven]

Ahh, now I see what you mean. The wetted surface area is larger than zero, meaning at least part of your hull is submerged. The hydrostatics aren’t calculated though. This probably means that you have some leak points in your model. See also this post.
You can easily check this by selecting the “check model” option from the tools menu.

[S . Warr]

Thank you, sir.

I knew that I had leak points, but they weren’t a problem before :unsure: .

My next step, is to eliminate all, and see if the report changes. (I’m sure that it will 😉 ).

I’ll post the result immediately.

S/F, Phil

[Marven]

Phillip wrote:

Thank you, sir.

I knew that I had leak points, but they weren’t a problem before :unsure: .

That’s correct, v4 tests for leak points more rigorously in order to avoid problems in some of the professional extensions.

[S . Warr]

I removed the Foredeck and Cockpit (both of which were developed as “Parts” – to permit me to try different combinations when fitting electronics (this is a Radio Controlled Boat).

The Hydrostatic Report is now accurate! 🙂 I still need to shave 0.191 tonnes of displacement, but this is do-able with some modifications to the appendages B) .

I’ll worry myself with re-attaching the Foredeck & Cockpit after I get the displacement “right” (I’ll have to work on that a bit too) :unsure:

Thank you for all of your help!!!!!!!!!!! 🙂

S/F, Phil

[MICHAEL KERR]

Hi Phillip, remember that model of your boat I sent you thats the correct way to avoid leak points between the hull and deck + transom. 4.18 as a niffty tool to extrude a deck and transom in one go,( under Edge Editing, 2nd icon, deck extrude edges along an arc) just highlight the sheer between the control points (not the control points)from the bow all the way to the transom CL insert some data for curature and hey preso, then you just have to mould it into shape, remember the shortest distance and weight betwwen 2 points is a straight line, although not as pretty as a curved one. Or just use the model I sent you.
Mike

[MICHAEL KERR]

Phillip I forgot something, you have a rudder shaft
which has leak points, in the layer properties just uncheck the hydrostatics on it other wise your data might not appear.
Mike

[S . Warr]

Mike,

Thanks for the clarifiation (I was wrestling with trying to figure out how you had so easily fixed my errors :unsure: .

Now I know (leading off with Descartes’ theorum :dry: ), and will use this as follows:

1. Extrude sheer line using only control edges,

2. Import parts (cockpit and foredeck),

3. Join parts to extruded sheer, then

4. Collapse previously extruded edges.

Sound right?

After, I’ll work again on the transom, but I’m thinking to do a scooped transom now in an attempt to remove some extra weight.

Thanks for dropping in to the forum and lending your wisdom.

As a courtesy, and if you’re interested, I’ll send you a copy of the file after I adjust the displaced volume and do the above.

BTW, rudder shaft has been temporarily deleted (now a part) and does not affect Hydrostatics.

The most significant information here is to omit the control points when extruding control lines :ohmy:

S/F, Phil

[MICHAEL KERR]

Phillip,
sounds like your making a lot of work for yourself,
I cant advise you on how to join the imported parts to an extruded sheer maybe Marven can, now before you pull all of your hair out of your head, think about using the model I sent you, its already got a fore deck, cockpit and scooped transom, and its still got the rudder post in it, and no leak points (excluding the rudder post). But who am I to spoil your party, go for it. Ill send that model to you again just incase your deleted it.
All the best
Mike

[S . Warr]

Mike,

I certainly did not delete your sage input to my effort 🙂 .

“Leak Points” are not terribly important to me, as each of the five major components (hull & underwater appendages, foredeck, cockpit, rigs & sail plans ( x 3)), need to be developed, evaluated, as seperate components before incorporating as a complete design.

Was that a run-on sentence :unsure: ?

Please remember, I’m designing to build myself. The actual build process may require some changes :ohmy: . Simply true of all interface between designer (I have not earned the title of architect) and builder (same afterthought), further followed by changes required by the users :silly: .

With the foregoing in mind, one can easily see how how I have wrapped the axle before, and will most probably do so in the future :blink: .

But, I know that I have friends who are always there to help me 🙂 .

Thanks Mike! My plan is to “sew up” my design holes, and send you re-vamp tomorrow for “Peer” (no claim in my part) review,

S/F, Phil

[John Owles]

Marven,
I seem to have the same problem.

I loaded a design that I have been working on, and completed to physical testing, but no hydrostatics are showing. On looking at Philips attached data, the same data is showing as well as the same lack of data.

I have only had a quick scan round but I certainly like the look and feel of this version.

All the best

John

[S . Warr]

John,

Try addressing the Leak Points (per Marven’s advice) – it worked for me.

Mike,

You did a great job on correcting my model earlier, but I have significant re-work into the foredeck and cockpit (to include placement of mast ram/partners, control lines, etc.). Rather than go back and re-do, I’m going to try to continue with them as parts.

As in most designs, all of the parameters are a moving target…

S/F, Phil

[MICHAEL KERR]

If no Hydrostatics first turn control points ON then go to Display—>Leak points Only and only leak points will be displayed and all other control point will disappear. This is a simple but a brilliant tool, maybe not appreciated so much in smal boats but can you imagine how many there might be in something the size of a merchant ship.
When I first discoved this tool I was that impressed I was going to sacrifice a goat towards Marven, unfortunately me, and fortunately for the goat, I didnt have one handy,
NEAHHH NEAHHH………NEAHHH

[John Owles]

Leak points from appendages were indeed the proplem and the solution is in Layer Properties (Wow, looking in there that was a surprise. Very impressive). I need to look right through DS before getting excited.

John

[Robin Upshon]

I have just downloaded the new version and must say it looks and feels much better. However. I cannot get the properties of volume,displacement,waterplane and Initial stability info to show in Design Hydrostatics. I have tried turning on “control points” and “leak points only” but with no success.

Any help would be appreciated.

Best regards
Bob

[MICHAEL KERR]

Hi Bob,
attach your file and we can look at it to sort it out.
Mike

[otaku]

Ditto here. Mike, the exact wording of your guidance didn’t match the menus for some items, but I think I followed your steps. I also get zero values for the first 4 or 5 lines of displacement, CB, and other coefficients. I even clicked on things unrelated, just to see if other things would be changed.

Is this something to do with it being free vs Professional? I note that the v3.12 or v3.x does not have this issue.

Also, i wish that the default install of v4.18 would not be that of the existing 3.x install. It should detect, warn of conflicts, and either suggest a new name or warn the user. Also, it would be nice if the new version would somehow pick up the last used files.

Overall, i like that it was updated, and some convenient icons are present.

I think that “windows, tile” still is randomizing the window placement afte tiling is invoked. I really would like it to tile without moving the windows around (I’m recalling that lizrds-on-mahjong-like tiles, where one clicks the the upturned to find the lizard and the tiles shuffle around… ehhehehe)

[Robin Upshon]

Hi Mike:
File attached, but this is not the only one, none of my files will give the information I mentioned which is a bit of a tee off as am working against a deadline at the moment and need the hydrostatics info that was on three of my files like yesterday.
By the way, it is a paid Pro version.
Cheers
Bob [file name=COMPLETED_MODEL_46_Inboard_Version.fbm size=7118]http://www.delftship.net/delftship/media/kunena/attachments/legacy/files/COMPLETED_MODEL_46_Inboard_Version.fbm[/file]

Attachments:

• COMPLETED_MODEL_46_Inboard_Version.fbm

[MICHAEL KERR]

Hi Bob,
I can see where your going wrong, I had no problem turning on the control points and then turning on leak points all those green points and there are quiet a few, are leak points (leak points green, normal control points blue). Its your methology thats screwing it up. Ill try to explain how Delft works.
Its a bit like wrapping a sheet around the hull from the center line (bottom of hull) to the deck center line. You have to do that first, so all the edge control points will end up on a center line. Then you raise or lower the control points on the deck center line and inbetween to get the different features of your boat eg cockpit, cabin, transom board, flybridge.
There is another way to make your boat, design your hull, extrude your deck to the center line, Save. Open Delft up again File–>Open–>
Cancel, you will have a blank screen, no hull, you can use the Add a box or Add a cylinder to design your cabin, flybridge etc then export as part and import into your hull design, move it onto your deck make sure it protrudes slightly thru your deck, then Edit–>Point–>Intersect layers and the 2 parts are joined together.
Mike

[MICHAEL KERR]

Bob
I had another look at your design hoping that I might be able to fix it for you but I cant, sorry mate.
So many people seam to screw it up including yours truly when I first started with Delft. So to clarify Ill go over it one more time for everyone.
Design you hull, once your happy with it then and only then extrude your deck ( I use extrude because you might want a bulkwark and extruding is the only way I can do it) when I extrude I do the deck and transom in one go to avoid leak points instead of doing the transom separately. So once that is done all the EDGE points of the Y coordinate are on 0.000 thats the hull center line and the deck centerline. Then I raise or lower the control points on the deck center line to form the cockpit, coach house, flybridge etc, then I raise the control points between the centerline and the sheer leaving a walkway around the deck. To form these things you will have to add more control points between existing control points (Add a new control point by spliting a control edge) and adding new edges by (spliting a face by adding a new edge) and once you do that they can be turned into creases.
PS make sure new edges dont cross over each other, the program wont let your do it.
If you add a cylinder for a mast or boom close the ends with a new face this can effect hydrostatics as well.
Once you get the hang of it, its a no brainer but its hard to explain.
Mike

[Robin Upshon]

Hi Mike:
Thanks for trying. Although not the greatest expert on Delftship we have been using Delftship Pro for over four years without a moments problem and have never had the hydrostatic info go blank on me. The trouble has only occurred since switching over to the new version two days ago and all files that I have imported have gone the same way. The real bone of contention is that I am finalizing modifications on a couple of our designs for a big tender and I am now without hydro info on even the original drawings.

We use Delftship for initial design, hydrostatics and plate development and then DXF the file over to Autocad to do the actual construction drawings. Unfortunately there is no way to reverse the process and import AutoCad into Delftship.

I am hoping it might just be a new licence issue as I loaded up the one that came with the email notification and I have sent a request for another licence in case that is the problem

Cheers
Bob

[MICHAEL KERR]

Hi Bob,
I havnt swapped over to the new version yet, Im running version 3.33 on my design computer and Im using the new version, well the free version on my other computer, I havnt received my email yet. My 3.33 version is the pro version I had no problems opening up your file in 3.33 so
do you still have your old version, if so try opening up your design in there and if you dont have it get in contact with Marven he should have a copy of old version and he can send it to you.
Mike
PS Unfortunately some of the hydrostatics is missing in 3.33 as well but its worth a try.

[MICHAEL KERR]

Hi Bob,
I had another go at your boat but couldn’t get far so I did a design for you its a bit rough but you might find some use for it, even if its only good as a reference, remember you can scale it up or down to your size. It has no leak points and all the hydrostatics are there.
Mike [file name=Boat.fbm size=34355]http://www.delftship.net/delftship/media/kunena/attachments/legacy/files/Boat.fbm[/file]

Attachments:

• Boat.fbm

[Robin Upshon]

Hi Mike:
Once again thanks for your efforts and I see what you are saying. I guess the older version was more forgiving on leak points and I took your advice and loaded up Version 3 into my laptop and loh and behold, the hyrostatic data etc. shows up just as it did before I changed over to Version 4 on the desktop.
I guess, I will have to re-work existing files in the old version and keep Version 4 for new projects. At least we have actually modelled the design I sent to you over into Autocad and actually built from the design. See our website at http://www.kelticstar.com
Regards
bob

[MICHAEL KERR]

Bob,
Theres nothing like a happy ending, I also understand why your vessel was so narrow now (air transportable), glad to be of assistance.

Mike

[John Owles]

The new v4 is great. The only problem for some of my work is Leak Points.

Leak Point detection is a little too rigorous for designing open or part decked boats. It seems that there are two options to work around this sensitivity:-

1. Extrude a solid deck over everything. This is fine unless the boat is part decked, in which case I think option 2 is the only answer.

2. Have a copy of v3.2 for working on these types of boat. I have set up a new folder as Delftship_32 and reinstated v3.2. They are both working well together. Just don’t save a design in v4 if you may need to load it into v3.2

John

[S . Warr]

Has anyone figured out a “work-around” to open files developed in v4 in v3?

The leak points in v4 are problematic for me, and I’m concerned that I may not be getting correct displacement values :ohmy: .

S/F, Phil

[Marven]

Leak points shouldn’t be a problem if they are above the waterline. If they are below the waterline they can be a problem and hydrostatic values can be incorrect. That’s why version 4 doesn’t calculate hydrostatics if leak points become submerged. You could try version 3.2 which calculates hydrostatics even with leaks submerged, but the results are not guranteed to be correct in that case.

[S . Warr]

Thank you, Marven.

All of my leak points are above the water line, so I’m now back to trusting my v4 HS Data.

Still… Is it possible to move a v4 file to v3?

S/F, Phil

[Marven]

Only the professional version can save to previous file versions. If you have the free version and want to convert it to a previous version just send me the file by PM and I’ll convert it for you.

[S . Warr]

Marven, you are a saint (and the greatest salesman/customer support agent)! 🙂

Without a doubt, you have the kindness to lend “freeloaders” such as myself a helping hand – if only I could go “Pro” :unsure: .

I am sending my file, and appreciate all of your assistance!

S/F, Phil

[S . Warr]

Duh 😛

Marven, how do I PM you? :unsure:

[Marven]

Sorry :blush:
Use the following email address, but remove the underscores: info_@_delftship_._net

[MICHAEL KERR]

((Marven, you are a saint (and the greatest salesman/customer support agent)!))

Marven, don’t you just love Phillip, he realy knows how to suck. You other freeloaders take note of Phillip, this is how you suck-up to the Boss.
Then again you could be like me and buy the Pro version and your sucking days are over.

Mike

[S . Warr]

Mike,

You’re right on the money (I have none, however :ohmy: ).

Truth is that Marven provides a level of support that is exemplary.

S/F, Phil

[MICHAEL KERR]

Hi Phillip,
(Truth is that Marven provides a level of support that is exemplary.) No argument there, Phillip, if wisdom is wealth then your a rich man.
Now, I have no idea what that means but it sounded like the right thing to say at the time.

[otaku]

Hi!

Would it be possible or worthwhile to have an “auto heal” or “auto seal” for below-waterline leak points in a future version or a patch of the recent Pro version?

Also, what if some leak points are very close to the waterline, but then a draft is calculated or imposed to take the hull below a leakpoint? Does the software internally model waves and troughs to determine if a warning should be thrown if the hull and some still-water non-submerged leak points will sail through internally modeled/simulate waves that rise above any leak points?

[S . Warr]

Marven,

Thank you for the file conversion! (Yes Mike, I’m still “sucking” up to the Boss 😛 )

Interestingly, there are some differences in the volumes expressed in Hydrostatics (minor) between the two files (v3/v4). I’ll look deeper into these, and see if I can find some rationality.

I’ll post my results :dry:

S/F, Phil

[Author]

Posts