Simple design software....

[Oscarvan]

Does such an animal exist? And, if at all possible, for a MAC?

(Don't tell me I'm nuts.....I know.)

[Jim Ledger]

What do you want to design?

[willmarsh3]

Google sketchUp comes to mind.

http://sketchup.google.com/

[LocktownDog]

What kind of money are you willing to spend? This one is supposed to be the best in hull design software, but it runs $900.

http://cadcam.autoship.com/cadproductsservices/autoyacht/autoyacht.htm

Richard

[Oscarvan]

What do you want to design?

Valid question.... a boat. I know what it looks like above the water, i need to find ce/clr....righting moment, displacement. Were exactly to place the mast.....how much ballast. How big a rudder....

I know it's complex. A lot of it is intuitive....but you'd just hate to build it and find out it will only sail in circles......

[Don Z.]

You may be able to find an old version of MaxSurf. It will do that, but they no longer support the Mac edition of the software. It will get the job done.

[Oscarvan]

I'll try that. Thanks.

On a side note....what did designers use before computers? Endless calculations? Modeling?

Is there valid design testing in modeling?

[Donn]

Google sketchUp comes to mind.

http://sketchup.google.com/

Very cool! Thanks for the link.

[sv Lorelei]

Oscar

Get yourself a copy of Skene's Elements of Design (you can usually pick it up on Amazon or the likes. This will give you a leg up on figuring most of the basic stuff. And then once you have a grasp of that you can take it to computer.

[Texasgaloot]

On a side note....what did designers use before computers?


Cap't Nat used wood. Other than that, pencil and paper. Some calculations, but not endless.

[donald branscom]

The google sketchup only showed a house. I wonder if it does curved lines. also there are no system requirements listed

Mac OS 8.6 ,9,10 or above????

Many internet ads are only supported by OS 10 or above.
Of coarse that is not of a reason to buy a new computer just because you cannot see jumping flashing SWF files of Mortgage loans.

[Bruce Hooke]

I think Google Sketchup was suggested before you made it clear that you wanted to design a boat and not, say, a boarding ladder for a boat. You could use a generic drawing program to do what you want to do, but it will not really give you much of a leg up on the calculations you need to perform. So, your best bet is a program that is specifically intended to be used for boat design. The second choice would be a program that is designed for producing engineering-style drawings, and that will let you do things like calculate the area within a curve, which you can then use to run math the old way.

In all honesty, if you are fairly well along with drawings of the above water profile and plan, presumably all on paper, then I would follow Lorelei's advice and get Skene's Elements of Yacht Design and do the math the old way. It will be a good education in what the stuff you are calculating actually means, which will help you make better use of software if you eventually go that route, and for one boat it likely will be faster than learning how to use a new software package designed for drawing hulls.

The biggest problem with doing the math the old way will be calculating the areas under curves. The old way to do this was with a planimeter, which you could pick up on eBay most likely, but that is a lot of work for one hull. For a hard chine hull you can break the area up into triangles and calculate the area that way. For round-bilged hulls you can always fall back on the old method of laying the lines over a piece of fine graph paper and counting the squares.

[Oscarvan]

Get yourself a copy of Skene's Elements of Design

Funny...did that a half hour before I read your suggestion.

Cap't Nat used wood. Other than that, pencil and paper. Some calculations, but not endless.

That's encouraging. For the same reason that I am gravitating towards a wood boat with three strand lines and a big tiller, I would like to design it using simple methods.

On the other hand we communicate right here using technology....and I did use a pewter to make the initial sketch....

One day I want to be here and build with wood, smell cedar and linseed... the next day I want to infuse epoxy into a vacuum bag and build a 25 foot folding try that I can just lift out of the water with one hand, and sail on a beam reach in a 20 knot breeze at 22 knots. I'm having a hard time, though, getting over the toxic element, not to mention the fact that whatever I create will en up contributing to a landfill, in stead of returning to the food chain.

The price of improved technology and performance....is it worth it?

It's the great dichotomy of our time, and my life in particular.

[Bruce Hooke]

Keep in mind three things about the intuitive method of designing boats:

1. The people who did it this way generally would have had a lot of experience under their belt before they starting designing boats.

2. They tended to make boats that were slight modifications of previous proven designs that they knew well. So, if you are going apply this method you should take the same approach. Yes, the great masters (like NGH) took more radical leaps, but they were great masters of the craft for a reason and I'm sure they started out by taking less radical leaps while they learned the trade.

3. It was not uncommon to do things like include some inside ballast that could be shifted around to compensate for the boat not floating right on her lines when she was launched.

While Capt. Nat carved hulls to design boats, this did not preclude him from using the carved hull to pick up the lines and then doing the math on those lines. Does anyone know for certain how much math he applied?

That said, you can do the math just fine without using a computer!

[Donn]

The google sketchup only showed a house. I wonder if it does curved lines.

It does curved lines, and it does boats.

There are 1300+ boat models in Google's 3D Warehouse (http://sketchup.google.com/3dwarehouse/search?q=boat&btnG=Search&styp=m&reps=1&start=0).

It supports Mac OS X (10.3.9).

[Oscarvan]

The biggest problem with doing the math the old way will be calculating the areas under curves.

How about a scale model, then measure water displacement.....?

[sv Lorelei]

That said, you can do the math just fine without using a computer!

But why bother? The computer is vastly superior to a slide rule and a legal pad. Skene's will give you enough background as to what you need to know and what most of the more common elements and ratios represent and why they're important. It'll also give you some "good enough" formulas for estimating a lot of the stuff you'd generally use calculus to get a "precise" number on. Keep in mind, precision is relative to the building process and materials used.

[Oscarvan]

2. They tended to make boats that were slight modifications of previous proven designs that they knew well. So, if you are going apply this method you should take the same approach. Yes, the great masters (like NGH) took more radical leaps, but they were great masters of the craft for a reason and I'm sure they started out by taking less radical leaps while they learned the trade.

3. It was not uncommon to do things like include some inside ballast that could be shifted around to compensate for the boat not floating right on her lines when she was launched.

Understood and agreed. The basic design I'm working off is the traditional channel cutter-ish workboat, be it French, Bristol, Cornish crabber...all same genus similar species. The only thing I'm changing somewhat drastically is under water.

I would do a test launch early in the game to see how she floats.....I have thought of leaving room for adjustable ballast, makes sense. One way to do that is to have multiple options on ballast tank locations, as we are talking trailering here. Removable and adjustable....

[Spokaloo]

OS-X allows you to run multiple OS's concurrently, which allows HULLS and DELFTSHIP to operate. You just need to work in the secondary OS to run the software.

E

[Bruce Hooke]

How about a scale model, then measure water displacement.....?

It is a lot of work to build a scale model that actually has the proper distribution of weight, which is what you would need to do a true flotation test. If you built a simple solid wood model you could check how much it displaces (but to do that accurately you would need to build a fairly large model and likely build a custom tank to allow you to get an accurate measurement of the change in water level), but I don't think you could get the center of buoyancy without a good bit of messing around and a good bit of calculating. I don't think there is any way to use a model as an easy way to get the area of each station, which is really what you want for most of the calculations.

[Bruce Hooke]

Understood and agreed. The basic design I'm working off is the traditional channel cutter-ish workboat, be it French, Bristol, Cornish crabber...all same genus similar species. The only thing I'm changing somewhat drastically is under water.

I would do a test launch early in the game to see how she floats.....I have thought of leaving room for adjustable ballast, makes sense. One way to do that is to have multiple options on ballast tank locations, as we are talking trailering here. Removable and adjustable....

If you are changing the underwater part drastically then as far as the calculations go, you cannot make any claim to be following an existing model closely. The calculations mostly focus just on the underwater area.

A test launch early in the game sounds nice, but by the time you are to the point where you can do a test launch you will already have committed a huge amount of time and resources to the project and will have few options for correcting any serious problems uncovered by the test launch.

I would strongly suggest that you need to do one of two things:

1. Get whatever software will solve the problem and learn how to use the software and then put it to use.

2. Learn how to do the math "by hand" (a spreadsheet application can greatly help with this process) and do it.

[Bruce Taylor]

It does curved lines, and it does boats.

Sketchup is a great drawing tool and, for such an easy-to-learn package, amazingly versatile, but it doesn't have such basic marine design features as a hydrostatics report, areas, resistance calcs, plate development, and so on.

TouchCAD seems to be the most popular Mac boat design tool, but I have no idea what functions it offers.

As spokoloo says, you might look into running DELFT!ship/FREE!ship (and other useful marine programs, such as Archimedes and Michlet) in a parallel Windows OS, or else in a PC emulator.

[Oscarvan]

OS-X allows you to run multiple OS's concurrently

Sort of, OSX and Classic. Delftship is Windows, so I would need to run softwindows....there's a lot of issues with that.

[Bruce Hooke]

But why bother? The computer is vastly superior to a slide rule and a legal pad. Skene's will give you enough background as to what you need to know and what most of the more common elements and ratios represent and why they're important. It'll also give you some "good enough" formulas for estimating a lot of the stuff you'd generally use calculus to get a "precise" number on. Keep in mind, precision is relative to the building process and materials used.

I never said anything about a slide rule. In fact I would recommend a spreadsheet and a calculator. The reason to do it "the old way" (using the formulas in Skene's) is quite simply that for one boat it is likely to be faster than learning a new software package and getting the proposed hull entered into that software package. If he actually has a complete lines drawing I'd venture a guess that in an evening of work he could churn out the basic numbers on displacement, center of buoyancy and so on using the formulas in Skene's. I'd bet that at the end of a similar evening spent going the software route he'd still be messing around with figuring out how the software works, and not be anywhere close to having the hull entered into the software.

If the software package can do fancy calculations such as plot the stability at different angles of heel, something that is a lot of work to do on paper, and if such calculations are desired, then that would justify going the software route.

[Bruce Hooke]

It should be noted that as far as I know there is no easy software solution to calculating the center of gravity. To do that you have to simply sit down and start adding up the weight and moment arm of each element of the boat. A slow, tedious but essential process. A spreadsheet is a big help in doing this.

[Texasgaloot]

I would strongly suggest that you need to do one of two things:

1. Get whatever software will solve the problem and learn how to use the software and then put it to use.

2. Learn how to do the math "by hand" (a spreadsheet application can greatly help with this process) and do it.


It occurs to me that there might be a third alternative here at this point. By the time one pops a bunch of cash down on software to analyze one's "ideas," or follows through with the ambitious project of drawing hulls, views, lines, and from there running the calcs on something that may or may not be feasible, building, and then launching one's dream, one might be better off commissioning someone who has done this a time or two. If your dream does happen to be a somewhat radical departure from the obvious recognized forms and turns out disappointing performance (at the very least,) the commission suddenly begins to look like a much smaller part of the overall investment. Call me conservative.

[Dave R]

Yes, you can draw boats with SketchUp however I don't think it is an approporiate tool for designing them. It uses straight line segments to approximate curves and because of that, it is difficult to create fair curves.

It might be a good place to start working out the looks of a boat design but, with the free version at least, you cannot export a file that could be read by another application.

Here are some examples of boats I've done in SketchUp.
http://img.photobucket.com/albums/v506/weekender410/cradle.jpg

Based on Bruce's Vesper drawing
http://img.photobucket.com/albums/v506/weekender410/Vesper.jpg

http://img.photobucket.com/albums/v506/weekender410/Weekender/weekender5.jpg

http://img.photobucket.com/albums/v506/weekender410/Quyet%20Time/halfhull2.jpg

It is handy for working out detail stuff though,

Weekender steering setup
http://img.photobucket.com/albums/v506/weekender410/Weekender/steeringModified.jpg

Stern hatch on Weekender
http://img.photobucket.com/albums/v506/weekender410/Weekender/SternHatch.jpg

http://img.photobucket.com/albums/v506/weekender410/rudderboxV6.jpg

http://img.photobucket.com/albums/v506/weekender410/boom1.jpg

If you're interested, there's more SketchUp work here. (http://smg.photobucket.com/albums/v506/weekender410/?start=all)

[Oscarvan]

Learn how to do the math "by hand" (a spreadsheet application can greatly help with this process) and do it.

Oops, missed your post. I plan to do just that, and I have, and am versed in the use of, Excel.

TouchCAD looks promising, and there is an educational function for le$$....one of the kids wants to be a robotics engineer...we'll get him started early.

[Oscarvan]

If your dream does happen to be a somewhat radical departure from the obvious recognized forms and turns out disappointing performance (at the very least,) the commission suddenly begins to look like a much smaller part of the overall investment. Call me conservative.

That is a good point, and valid for many people. My "departure" is not THAT radical.....and if I would have done the same with my first engine rebuild, or my first construction project, or my first boat project, like some people told me to do, I would still be paying people $25-$100/hr for those various activities. Now I have piles of tools and turn out some relatively serious projects.... I have my mind set on learning how to do this. And, no disrespect to the resident designers, I don't think it is beyond my means to learn how to do.

BTW.....why do some of my posts take up to a half hour to show in the thread?????

[openboater]

Bearboat Pro 061001 - Helps design your own kayak/canoe/rowboat. (Free)
Bearboat Pro 061001
Bearboat Pro aids you in designing your own kayak, canoe, or rowboat... This app is best suited to wood-strip construction. Bearboat Pro is a sophisticated program that can also generate a stability graph for your design, represent it in simulated 3D, and allows you to export your design as a DFX file for use in CAD programs. However, it is still a work in progress that will be continually improved and upgraded so check back here at MacUpdate.com periodically to see if you have the latest stable version. The numbers the files begin with are the year, month, and day it was completed.




I got this in an email from a friend, I have no idea if it works.

but it's for a mac

[boatbear]

Good thread. I will confess to having a modelling software habit and you have provided some more apps to keep the beast satisfied. Delftship is a great little program. You can model with a table of offsets and tweak using control points. It provides lots of hydrostatic info (still mostly a mystery to me). I’ll see if I can find a copy of Skene’s to help here.

Oscarvan – I hope you find a way to try Delftship on your Mac. I have no experience with Macs but was under the impression that PC emulation was ‘do-able’ now.

DaveR – thanks for the SketchUp stuff. Your models are great and there are some amazing things in that link. I will give it a try. I have been using MoI (Moment of Inspiration) for that sort of detail work. Pretty quick to learn. It uses NURBS surfaces and can create some pretty fantastic shapes. It’s currently free but is for PC only, at this stage.

Openboater – Thanks for the Bearboat info. I have just downloaded the software and manual and will have a play. There is all sorts of stuff on the Mariner Kayaks site that is worth a look; Drag prediction spreadsheets, etc.
It has a nice name, too.

Charlie

[Ed Burnett]

Bear in mind that whatever software you use, it will not make decisions for you that guarantee a good boat. The software will give you information that allows you to make design judgements, but as the designer it is your role to judge what is "good" or otherwise.

If you don't have experience with CAD programs I would suggest you stick with hand drawing and calcs with the aid of a spreadsheet or two. It is more likely that you will keep the design under control if you use these methods and there are various books which will guide you through what is a very pleasant and tactile process.

NGH and the like did plenty of calculations. Many designers from that time were very accomplished engineers and the science was quite well enough advanced to enable them to do the majority of the calcs we would do today on most projects. Computers merely allow us to go through more itterations in less time.

The bottom line is that good design is all about ending up where you wanted to be. Predictions of weights, balance (of all sorts) and so on are fundamental to this and not doing them means you trust to luck. Professional designers of 100 years ago will have been just as reluctant to do this as we are today.

[mmd]

An old saw from a good friend and mentor:

"A computer is a device that enables you to make bigger mistakes faster, with more confidence!"

[DaveWhitla]

That is a good point, and valid for many people. My "departure" is not THAT radical.....and if I would have done the same with my first engine rebuild, or my first construction project, or my first boat project, like some people told me to do, I would still be paying people $25-$100/hr for those various activities. Now I have piles of tools and turn out some relatively serious projects.... I have my mind set on learning how to do this. And, no disrespect to the resident designers, I don't think it is beyond my means to learn how to do.

BTW.....why do some of my posts take up to a half hour to show in the thread?????

Good for you. I sadly suffer from the same illness, only worse. Being a long time Unix user (now Mac OSX) I was very disappointed to find a void in the area of such software for Unix - so I have begun to write it. Don't hold your breath though ... my work commitments are pretty bad making this software project take longer than normal - and I've had to dig out some texts on analytical geometry and numerical analysis which I haven't opened in over 10 years. :o

[MiddleAgesMan]

Greg Carlson's Hull program is free. I don't know it you can run it on a Mac, though.

[peterAustralia]

hi

This question has come up before. I have heard of 'carlson designs', and of 'hulls' and of 'freeship' but have never used any one them. I have used and like hullform. I use the free version. No it does not run on a mac but you can buy a second hand pc for $30, do your hullshape and give the pc away for free when done.

Hullform works by offsets. You say where the stations are, what the half breath is, what the height above baseline is and then enter a displacement. It will calculate C of G, CLR, trim calcs, area above and below the WL, some calcs to do with the smoothness of the hull..... something coefficent..

I guess my point is, say you start with your boat, you design on paper, you get some dimensions etc, then you can go to hullform and enter these offsets and it will show you where the C of G has to be, what the CLR is etc etc. Thus you can use it as an aid to conventional pen and paper, not as a replacement. It can be a bit tricky to use this software, and others may be easier. However it you already have your offsets, then entering them into the computer only takes a few minutes. If you decide to go down this route and need advice you can contact me on this list for tips, if you wish.

regards,
n peter evans

[DaveWhitla]

The software I am working on is based more closely on traditional lofting. I specifically want to digitise the lines plans in a way sort of like tracing using parametric natural cubic splines to interpolate the major points of intersection which are typically measured to produce offsets. The splines ensure the same fairness that would be obtained by using perfect battens on a loft floor.

The lines once digitized are modelled in multiple schemes each suited to a particular purpose. The ultimate aim is to calculate accurate hydrostatic and hydrodynamic data for a given model so that changes to the lines can be quickly "tank tested" in a virtual tank. Determining centers of bouyancy, mass, pressure etc are all part of this and will take into account the internal fitout if desired so that ballast can be accurately calculated for a new design - something which has traditionally been a largely trial-and-error process.

My main reasons for wanting to do this are that I haven't been able to find an existing design which suits my needs, so I am trying to modify a very old traditional pilot-cutter design which, true to the old ways of building, was built sans-plans. I have only a reverse-engineered set of drawings. I also want to try changes to this old design to produce particular seaway characteristics from more modern design ideas - sort of designing the best such boat as could have been had computer-aided numerical methods been available in the 1870s.

I have tried most of the software tools available. These were almost all Wintendo-only - I prefer my Mac - and were either too general to be of much use to me in the specifics of ship design or, as was the case with FreeSHIP (now DelftShip), too painfully slow to use interactively without going mad. (FreeSHIP is written in Delphi - blech!!)

Regarding offsets ...
Using offsets alone is usually error prone - indeed there are often a significant number of errors in tables of offsets as it is a tedious task to generate the table and the width of a pencil line on a set of plans is significant in producing errors. This is mentioned a bit in Howard Chapelle's books as well as other more contemporary texts.

[Oscarvan]

In an ironic twist my MAC is starting to show signs of fatigue....(I've had it for 5 or 6 years and shlepped it all over the world) The new MAC's come with the duo chips.....it may solve the issue. Still would like something native for OS-X.

Meanwhile the office of Teale, Kene and Gerr have reported for duty on my front door step.

[Michael s/v Sannyasin]

for what it is worth, the book Wizard of Bristol about Nat, written by L. Francis has a bit of detail about how Nat used his models then took the lines off of them. In fact, I think he said that there is a machine that he used to trace the lines off the hull of the model.

Nat had a degree from MIT and no doubt he did the calculations, but from L. Francis' description, it sounds as if he could do a lot of that in his head. I'd like to live in that brain for a bit just to know what that was like.

IIRC, he said that prior to one of the America's Cups, they'd spotted the Lipton team towing a model, sort of like the modern day tank tests, and Nat found a way to improve on those tests as well.

I believe that Nat sculpted his models out of a solid block of wood (or maybe a couple laminated together, versus building it up as you would with planks and frames etc.

Well worth the read.

[Oscarvan]

Well, moving right along. Reading Skene, and Teale.

Getting some questions answered here, and concepts clarified. I am impressed with the caliber of folks here, and the wealth of experience. It is truly an honor and a pleasure to be among you.

MAC G4 had been making scary noises for a while, also refused to give up, or play a CD... :( So finally broke down and bought a MACBook.....with Parallels, an OSX based virtual PC that lets you install Windows.....and DELFTSHIPfree.... :cool:

I will be VERY entertained on my upcoming layovers......:D

[boatbear]

New 'puters are wonderful things (for a while). If you get stuck with Delftship send a PM and I'll try to help. I'm no expert, but have modelled a couple of hulls using offset tables.
Charlie

[Oscarvan]

I appreciate that, thanks! I'll read the instructions first..... ;)

[DaveWhitla]

If you are going to run Wintendo apps on your new Macbook (as I do occasionally) I'd recommend VMWare Fusion over Parallels ad BootCamp over either.

I was rather unimpressed by the slowness of DelftShip even running natively in Windoze on my BootCamp machine (a maxed out Macbook Pro 2.4). It has the most intuitive user interface out of those I have tried though. It is also more aligned with your needs as a boat designer than more generic 3D modelling tools like Rhino.

I'd be interested to hear about things you find difficult or lacking to feed into my own design.

[Bruce Taylor]

I was rather unimpressed by the slowness of DelftShip even running natively in Windoze on my BootCamp machine (a maxed out Macbook Pro 2.4).

Could it be that you were running the program in High precision mode? No doubt you know this already, but when working on a model in FREE!ship / DELFTship, it's best to set precision to low or medium.

It has the most intuitive user interface out of those I have tried though. It is also more aligned with your needs as a boat designer than more generic 3D modelling tools like Rhino

RhinoMarine offers a full range of boat design tools.

[Oscarvan]

I'd recommend VMWare Fusion over Parallels ad BootCamp over either.

Too late....pewter came with Parallels. I did get the 2.16 with the 2G RAM.....

I'll post after I play with it for a while.

[Andrew]

???

[Oscarvan]

???

I'll second that. As stated, new pewter came with Parallels, OSX and WindowsXP and I've downloaded Delftship-free.

[Dave R]

Thank you, sir. You, too, can do it if you'd like. ;) I can teach you.

[Dave R]

Since SketchUp was mentioned at the top of this thread, I thought I'd post the following image. Although not intended as something to build from, I think it is pretty impressive for a SketchUp model. Rendering was done in a different program. It's not my work and I can't vouch for any sort of accuracy, either historical or nautical.

http://img.photobucket.com/albums/v506/weekender410/vray-sailship-1.jpg