How to create lines drawings from a model?

[Omeron]

I am an amateur, trying to design a 38ft sailboat.
Instead of starting with drawing lines, i wanted to create a scale model.
The first step for me was freehand drawings, to get an idea of the
finished boat, which i did.
Second step was to create a solid scale model (1/14) which is nearing
completion.
Now i have in my hands a solid block of the boat which is roughly 2.5 ft
in total length. Deck and superstructures not yet done or decided.
My problem now is how to retrieve the lines from the model to get to the
actual lines drawings.
I tried to mark and measure a total of 30 points on the hull in x,y,z, and
tried to feed them into freeship 2.6 program.
The resulting boat is close in appearance but not the one i have.
Because unless the points measured are an edge,defining the boundary
such as sheerline or keel,all other points become a control point and
produce a different curve. They do not become an actual point
on the surface of the hull,as measured.
I think it is almost impossible to play around with those control points
so that the curve goes through the measured point.
So i am stuck here.
Is there a way to accurately retrieve lines from a model, with or without
using software such as freeship?

[nero]

The more measure points you take the closer to the hull you will come. In TouchCad, you can add a series of points into a ruler (line). Then you command TouchCad to reduce the number of control points. The result is excellent!

Not sure if freeship has this ability.

[lazeyjack]

I am an amateur, trying to design a 38ft sailboat.
Instead of starting with drawing lines, i wanted to create a scale model.
The first step for me was freehand drawings, to get an idea of the
finished boat, which i did.
Second step was to create a solid scale model (1/14) which is nearing
completion.
Now i have in my hands a solid block of the boat which is roughly 2.5 ft
in total length. Deck and superstructures not yet done or decided.
My problem now is how to retrieve the lines from the model to get to the
actual lines drawings.
I tried to mark and measure a total of 30 points on the hull in x,y,z, and
tried to feed them into freeship 2.6 program.
The resulting boat is close in appearance but not the one i have.
Because unless the points measured are an edge,defining the boundary
such as sheerline or keel,all other points become a control point and
produce a different curve. They do not become an actual point
on the surface of the hull,as measured.
I think it is almost impossible to play around with those control points
so that the curve goes through the measured point.
So i am stuck here.
Is there a way to accurately retrieve lines from a model, with or without
using software such as freeship?

what I would do is drag the point around, then hide the net, then measure the hull you can see the measures as you move mouse onto the lines, as the top of screen
Hello Nero how are you, you home or home?

[Guillermo]

Is there a way to accurately retrieve lines from a model, with or without
using software such as freeship?
Yes, the old way:

"In the years before Naval Architecture had evolved, boat and ship design was developed through model construction. A master builder would fashion a hull form to the requirements of the client. The model would then be cut vertically down the center, leaving two halves.One half would be cut along the horizontal planes, known as waterlines, at evenly spaced distances. The other half would then be cut vertically at evenly spaced distances, known as "stations".

These pieces would be laid out and traced in outline on wood or parchment. The dimensions were then expanded to reflect the true size of the vessel, in what is known as the table offsets. This table was used to put the vessel lines down on the lofting floor, from which the construction forms for the centerline structure and framing systems were made. After the process was completed the "waterline" pieces of the model were reassembled and that half was mounted on a wooden backing plate, and often put in the master builder's office to show off the boats that the yard had built."

You can find some books on the technique by googling around for 'half models lofting' or similar.

Cheers.

[lazeyjack]

Yes, the old way:

"In the years before Naval Architecture had evolved, boat and ship design was developed through model construction. A master builder would fashion a hull form to the requirements of the client. The model would then be cut vertically down the center, leaving two halves.One half would be cut along the horizontal planes, known as waterlines, at evenly spaced distances. The other half would then be cut vertically at evenly spaced distances, known as "stations".

These pieces would be laid out and traced in outline on wood or parchment. The dimensions were then expanded to reflect the true size of the vessel, in what is known as the table offsets. This table was used to put the vessel lines down on the lofting floor, from which the construction forms for the centerline structure and framing systems were made. After the process was completed the "waterline" pieces of the model were reassembled and that half was mounted on a wooden backing plate, and often put in the master builder's office to show off the boats that the yard had built."

You can find some books on the technique by googling around for 'half models lofting' or similar.

Cheers.

I still do that guillo, put the lines down on the floor, especially if I have never worked with the CAD man before:)) you still need to draw the stem, the sheer in plan(if you are going to form a big caprail) and you still need to draw the body plan, mast step etc, most buiders do a half model of the boats they build, just to hang on the wall, looks great

[nero]

Down side of doing it the old way is your model is lost.

Perhaps, now that he has a good idea of the hull shape he wants, he could create a model with some software? The advantage is he could know displacement. Also, the offsets coming out of the program ( if done correctly) will be fair. Yes, I know that lofting will solve this also.

Lazyjack, I am still in Illinois. Getting ready to glass the outside of the first hull. Will dry lay the glass day after tomorrow and wet it out the next day. Looking for volunteers if you want to fly in for the week. (smile)

[lazeyjack]

Down side of doing it the old way is your model is lost.

Perhaps, now that he has a good idea of the hull shape he wants, he could create a model with some software? The advantage is he could know displacement. Also, the offsets coming out of the program ( if done correctly) will be fair. Yes, I know that lofting will solve this also.

Lazyjack, I am still in Illinois. Getting ready to glass the outside of the first hull. Will dry lay the glass day after tomorrow and wet it out the next day. Looking for volunteers if you want to fly in for the week. (smile)

that'ud be neato, but me flying NZ to stick an engine in a newbuild
best way to make a half model, on cad, make a waterline every 10mm, then put a 10mm a 4 sized piece of ply in your hp desk printer, and so on::P

[lazeyjack]

thanks to the coward who posted this
An Arrogant **** aren't you. feedback from this thread:))

[Omeron]

lazeyjack, whats wrong with you man?
This is the second time you are doing this to me.
We are probably living in different ends of the world.
And i dont take my computer to bed with me.
Go back to the maltese falcon thread and read my last post.

Sorry to all others. And thank you for your comments.
Ofcourse i do not want to loose the model by cutting it up.
I shall think about how to get it done and give it another try
by using freeship.

[lazeyjack]

lazeyjack, whats wrong with you man?
This is the second time you are doing this to me.
We are probably living in different ends of the world.
And i dont take my computer to bed with me.
Go back to the maltese falcon thread and read my last post.

Sorry to all others. And thank you for your comments.
Ofcourse i do not want to loose the model by cutting it up.
I shall think about how to get it done and give it another try
by using freeship.

what the hell are you talking about?

[lazeyjack]

all i said was someone who read thsi gave me bad feedback, not you!! I love turkey and turkish people

[Omeron]

Well, thats ok then.
I didnt understand what you were referring to, but since
i posted the original thread, i thought you were calling my name.
sorry for the misunderstanding.

[lazeyjack]

Well, thats ok then.
I didnt understand what you were referring to, but since
i posted the original thread, i thought you were calling my name.
sorry for the misunderstanding.

i will be back in ist August be nice to meet

[Omeron]

lazeyjack, i am trying to understand your 10mm waterlines suggestion.
what i did before was, six stations between stem and transom, and five
lines vertically.
top line being the sheer, and the bottom was the keel. additional three
lines equally spaced in between,giving me a matrix of 30 measured stations.
How is that any different to creating waterlines 10mm apart?
Well probably i would end up with many more points, but wouldnt the same problem prevail? ie the curves still not going through the stations.
What would happen if you treat all points as an edge? as if the hull has multiple chines, and then try to smooth them out? Would that be possible do you think?

[Omeron]

With pleasure. Pls let me know when in Ist.

[lazeyjack]

lazeyjack, i am trying to understand your 10mm waterlines suggestion.
what i did before was, six stations between stem and transom, and five
lines vertically.
top line being the sheer, and the bottom was the keel. additional three
lines equally spaced in between,giving me a matrix of 30 measured stations.
How is that any different to creating waterlines 10mm apart?
Well probably i would end up with many more points, but wouldnt the same problem prevail? ie the curves still not going through the stations.
What would happen if you treat all points as an edge? as if the hull has multiple chines, and then try to smooth them out? Would that be possible do you think?
oh i,m sorry this was a joke,about printing plywood!!
But how they make a model is they use the plan view of the boat, say they scaled 10 to 1 and the waterlines became 10mm apart instead of 100 on the true full size thing, then you would have the plan view of the boat at each waterline, , the model wood thickness 10mm, then you would cut this out on bandsaw or jigsaw and the the the next waterline down and so on you would then have all these slices, glued one on top of other, then you would sand the corners off, to make fair hull, the top slice would be your sheer height and plan,