Can FreeShip give me horizontal slices?

[alexlebrit]

I'm thinking of glass on foam core construction, and the logical thing to do would be to cut big horizontal sheets of foam following the hull form and layer them up, then with some sanding I'll get the basic form and then I can glass.

I've got the hull in FreeShip, but can I work out a way to get these horizontal slices out? Nope, short of shifting the waterline about and printing each one individually.

Is there a way to do this, or perhaps a way to export to something else and do it from there (assuming the something else isn't ludicrously expensive)?

[Martijn_vE]

Export the coordinates of the waterlines to a text file and draw these manually on a piece of wood or cartboard. This is by far more accurate than puzzling small pieces of paper together. Make sure you have disabled the "simplify intersections" setting.

[Windvang]

Export linesplan with all waterlines as dxf., look for free or cheap CAD program (plenty around) use dimension function in CAD program to measure width at each station.

If you are talking about your pedal boat most plotting shops can print that out full scale (1 side of boat) for around 60 EU If you use cross sections instead that will even be less.

You don't have to shift waterlines you can select multiple.

[Guest625101138]

Alex
I think Martijn assumes you have set the waterlines.

You do this by <Calculation> <Intersections> select the Waterline button then the +N and set the spacing to the thickness of your foam - say 50mm.

You then Export the Offsets.

I have attached what I produced with the boat facing forward. So "0" is the stern.

I think you will find cutting the foam to be tedious. Even hot wire is difficult unless you have guides.

You could always simplify the lines to make it easy to build. Remember that water and air take less effort to move in gentle curves.

Rick W.

[alexlebrit]

Thank you one and all and especially thank you Rick. I wanted to start with a 1:10 scale model, so in fact I popped all the waterlines in FreeShip, selected Plan View annd then Printed that out using the pdf995 program, which will print to a PDF file. Then I opened that up using Photoshop and spent a bit of time splitting it into two contour maps, the first of the hull form and the second of the deck/superstructure form. Printed those out and had endless fun with Spray adhesive and 4mm thick polystyrene, glue and sandpaper, and voila, I know have a 1/10 scale model.

As FreeShip will print on a 1:1 scale, and I have tax deductable print costs I'm sorely tempted to do the same thing.

[Guest625101138]

Alex
You can reduce a step in the process by using the faithful right-click mouse button when you are in plan view. This allows you to save a bitmap image that can be loaded directly into your image handling software and scaled as required.

Would be great to have a printer that could print out big sheets. I am stuck with marking up although I can print out bulkheads for narrow hulls that save a bit of work depending on how I build.

Rick W.

[kengrome]

I wish FreeShip could produce transverse cross-sections with the mold borders marked on a grid -- like "develop plates" but perhaps called "create cross sections" instead -- so I could easily create the molds for building the boats I'm designing.

Any ideas of how I might do this now, or if it might become a feature in a future version?

[Guest625101138]

Ken
I am not sure if I got the correct understanding of your question. I have attached an image of what I think you mean.

Rick W.

[kengrome]

That's close Rick, but what I am actually hoping for is the coordinates of the intersections of the grid with the cross-section curves.

With the coordinates I can build very accurate molds, but without them I have to "guess" at the coordinates where the cross section curves intersect the grid.

The "develop plates" feature provides these coordinates of course, but only for the developed panels, not for cross sections that I would use to create my molds ... :(

[alexlebrit]

Rick you can indeed. The advantage to the method I described is that it allows you to scale things within the process, rather than having to scale up in an image editor - never an easy task. Also if you scale that way the thickness of your lines stays the same at 1 pixel, and the curves become curvier and less pixellated, whereas if you scale up the bitmap, you scale up the size of each pixel - if you see what I mean.

I'd thoroughly recommend pdf995, it's free to use, and very useful for all sorts of printing operations.

[Guest625101138]

Ken
You can get the text version of what I think you want using the Export to Michlet. Michlet works on a hull grid of intersecting waterlines and stations.

It takes some thinking effort to understand the data set. You also have to pull it out of the Michlet .mlt text file. I have done this in the attached Excel file. As a check I plotted the stations on a chart shown in the file. Note that the chart is not to scale. It also shows some obvious discontinuities on the centreline (bottom axis of the chart) due to the coarseness of the waterlines. The same thing happens when you use Michlet to produce offsets that are imported into FreeShip. It pays to have waterlines close together to avoid large discontinuities.

You can set the number of waterlines and stations when you export to Michlet. Also if you want to get the full hull you need to sink it. (Set the draft higher than the highest point). By choosing the right number of waterlines and stations during the export you can get nice even grids. I have used a 0.1m grid for the waterlines so this gives fair resolution for the size of hull shown. The Stations are at 0.4m intervals - maybe more than needed.

Rick

[nero]

Stacking foam to make a model boat may have worked well for you. Imagine the waste if you intend to do this on the full size boat.

It would be better to reproduce your intended building method when making your model. This helps to illiminate problems that at full scale could be project ending.

There is a technique of strip foam. It uses strips of foam like corecell to strip plank the boat. Never used it myself.

[alexlebrit]

Well it does of course depend on what you want to do with your model boat. If it's just to look at, have sat on your desk and wave around at visitors to bore them to death, then quite frankly who cares what it's made of, especially when it's 2 foot long.

And in fact i'm planning on using this method for the real thing too, it's really only a kayak-a-like thing, so I won't have huge amounts of wastage - the reason for doing this, was so that I COULD replicate the build, so as my foam comes in 2m x 1m bits, I started with 20cm x 10cm pieces of paper, so see how much wastage there would be.

[bhnautika]

Alexlebrit you seem to be confusing vector lines produced by CAD and raster used by graphic programmes. Take the lines you want out of freeship in DXF format and import them into any CAD. From there you can get any measurement you want to whatever accuracy you want.

[nero]

Alexlebrit
Can you post a picture of your model? How thick are the sheets of foam?

[alexlebrit]

Alexlebrit you seem to be confusing vector lines produced by CAD and raster used by graphic programmes. Take the lines you want out of freeship in DXF format and import them into any CAD. From there you can get any measurement you want to whatever accuracy you want.

Who knows? I know I certainly don't understand any of that, I'm afraid. I've managed to do what I wanted to do using just FreeShip, pdf 995 and Photoshop. FreeChip's multiple waterlines gave me the horizontal slices and the ability to print at whatever scale I wanted. Pdf995 pretends it's a printer and converts what would be the printed page into a .pdf file at whatever scale you previously selected. PhotoShop will open that and you can slowly and carefully delete the lines you don't want. In fact if you were using this on a 1:1 scale, you wouldn't have to go through Photoshop, the lines would be far enough apart not to be confusing.

Nero, i certainly will post piccies. I actually took them with my good old 35mm SLR and a 200mm zoom as that way playing about a bit it's possible to make the model floating gently on the local millpond look almost like it's full size (apart from the one with the duck in). The foam I used was 4mm thick paper backed foam, it's the type of thing PR people use to make pretty displays with. The real thing will use 40mm thick foam, used for insulation. Because the boat is a basically a large (semi) sit on top kayak, 6m long, by 1m wide and has a hull height oh about 40 cms, I wont need huge amounts of foam, and there'll be lots of off cuts from the larger bits which I can use lower down the hull. The superstructure itself will be just tortured PVC sheet, which when heated with a hot air paint stripper is possible to shape into gentle compound curves. Touch wood she'll look like this.

http://perso.orange.fr/eurochat/images/6metre_enclosed_1.jpg

[nero]

That is smoking! How are you planning to power it? Where are you going to use it? Transat?

Keep us up to date on your progress please. The boat/float/avec canard pict would be cool to post.

[alexlebrit]

Haha, transat? Nooooo more like Trans-Bretagne. For the ten years I've lived in France I've always fancied navigating the former Nantes-Brest canal. Depending on who you believe it's between 360-400 kms long, and has 283 locks!! Unfortunately it fell into disusue in the 1930's when they built a hydro-electric barrage across one of the valleys, effectively cutting the canal in two. Since then some of the locks have been sealed up, some have been fitted with kayak-slides, and some you just have to portage round.

I started off with the idea of just a longer wider kayak, something I could if I wanted to pop a one man tent on. Then the sun came out and I thought I'd need some form of canopy to keep the sun off my head. Then it poured with rain solidly for a week, with thunderstorms and I thought maybe some form of proper cockpit to keep the rain off, and then I thought "well if I'm having a cockpit I'll have a rear cabin too." And finally I decided I'd use the trip to raise money for charity, so in the interests of plugging the trip in the media, I thought it ought to look eye-catching.

So it ended up like that. I might even attempt to replicate the zebra stripes, because I think they look very cool.

So sorry to disappoint no trans-atlantic trips for me. But if she performs well on the Nantes-Brest I might take her up the Loire, and then dogleg onto the other canals till eventually I end up on the Mediteranian. That'd be a trip!!

Oh and power? Well my legs of course, none of this internal combustion for me, just a bloke, a set of pedals and decent French food.

[nero]

When you make it down to Marseille, look me up.

How thick is the foam core going to be? What is the total weight?

As long as you are staying off the sea, I guess the paint design would be great. If you do venture on to the sea all that red may act as a big squid lure! smile