On Nov 29, 2:41 pm, "Steve Lusardi" wrote:
Richard,
You have done a very good job of recreating a lines drawing on a computer,
but your effort has nothing to do with lofting. Lofting is laying out on a
wooden floor the full lines drawings full scale for the purpose of template
generation, one on top of the other using the table of offsets as an initial
starting point. Fairing the lines occurs during this process by driving
nails in the floor at line intersections and subsequently bending an
appropriate batten around the nails to scribe the line. When the battens
fails to bear on a nail, the nail is then removed and redriven at the
correct point. The offset from the table is then remeasured and entered into
a new table that is called the "corrected table of offsets". Only then can
templates be taken off the lofting for the manufacture of the individual
components to stand up the actual hull. This is not done with a mouse while
sitting comfortably in a chair. It is extremely hard work done on your hands
and knees for many days on end. No computer will ever replace this task,
even big ship yards still must bulletproof the table of offsets for CNC
cutting machines to be accurate.
Steve

"cavelamb himself" wrote in message

...



I thought I was a pretty good draftsman.
At least until I tried lofting hull shapes...
Buildings, machine parts, entire aircraft - no problems.

But fairing a hull can be a humbling experience.

Well, for grins and glggles, here are a few of my efforts so far.

http://www.home.earthlink.net/~cavelamb/draft.htm

Richard- Hide quoted text -

- Show quoted text -

:O

Steve Lusardi wrote:

No computer will ever replace this task,
even big ship yards still must bulletproof the table of offsets for CNC
cutting machines to be accurate.
Steve

Steve,

Maybe a decade ago this was true, but in the real world of today's
shipyard, the cut files are all done on computer, the plate is burned,
and erection starts the next week. The loftsman is a dying breed.

We (commercial naval architects) seldom provide tables of offsets any
more; just send 'em an IGES file of the 3D hull surface, or we produce
all the steel parts in house. No lofting required.

Evan Gatehouse

On Fri, 30 Nov 2007 06:16:55 GMT, Evan Gatehouse
wrote:

Steve Lusardi wrote:

No computer will ever replace this task,
even big ship yards still must bulletproof the table of offsets for CNC
cutting machines to be accurate.
Steve

Steve,

Maybe a decade ago this was true, but in the real world of today's
shipyard, the cut files are all done on computer, the plate is burned,
and erection starts the next week. The loftsman is a dying breed.

We (commercial naval architects) seldom provide tables of offsets any
more; just send 'em an IGES file of the 3D hull surface, or we produce
all the steel parts in house. No lofting required.

Evan Gatehouse

Aw shucks! You didn't even mention being able to run a ball bearing
along the panel seams before weldup! :-)

Brian Whatcott Altus OK

Evan Gatehouse wrote:

Steve Lusardi wrote:

No computer will ever replace this task,

even big ship yards still must bulletproof the table of offsets for
CNC cutting machines to be accurate.
Steve


Steve,

Maybe a decade ago this was true, but in the real world of today's
shipyard, the cut files are all done on computer, the plate is burned,
and erection starts the next week. The loftsman is a dying breed.

We (commercial naval architects) seldom provide tables of offsets any
more; just send 'em an IGES file of the 3D hull surface, or we produce
all the steel parts in house. No lofting required.

Evan Gatehouse


While the drawings look small, they are drawn in full scale.

Actually, sometimes much larger than full scale.
When zooming in to locate a point between a waterline and section
I may be as much as 100 x magnification.
Trying for .01 inch resolution.

Can't do that on the floor.

But that's the way it's done these days - and why the parts fit
so well (hopefully!).

Richard

Evan,
I did a bit of research and you are correct, it is now done that way. I
guess I am a dinosaur. God bless computers, lofting is a horrible task. I
know, I have done a lot of it in my life. However, I hesitate calling mouse
work lofting in deference at least to the way it was.
Steve

"Evan Gatehouse" wrote in message
news:rVN3j.3921$UQ1.364@pd7urf1no...
Steve Lusardi wrote:

No computer will ever replace this task,
even big ship yards still must bulletproof the table of offsets for CNC
cutting machines to be accurate.
Steve

Steve,

Maybe a decade ago this was true, but in the real world of today's
shipyard, the cut files are all done on computer, the plate is burned, and
erection starts the next week. The loftsman is a dying breed.

We (commercial naval architects) seldom provide tables of offsets any
more; just send 'em an IGES file of the 3D hull surface, or we produce all
the steel parts in house. No lofting required.

Evan Gatehouse

Steve Lusardi wrote:

Richard,
You have done a very good job of recreating a lines drawing on a computer,
but your effort has nothing to do with lofting. Lofting is laying out on a
wooden floor the full lines drawings full scale for the purpose of template
generation, one on top of the other using the table of offsets as an initial
starting point. Fairing the lines occurs during this process by driving
nails in the floor at line intersections and subsequently bending an
appropriate batten around the nails to scribe the line. When the battens
fails to bear on a nail, the nail is then removed and redriven at the
correct point. The offset from the table is then remeasured and entered into
a new table that is called the "corrected table of offsets". Only then can
templates be taken off the lofting for the manufacture of the individual
components to stand up the actual hull. This is not done with a mouse while
sitting comfortably in a chair. It is extremely hard work done on your hands
and knees for many days on end. No computer will ever replace this task,
even big ship yards still must bulletproof the table of offsets for CNC
cutting machines to be accurate.
Steve

"cavelamb himself" wrote in message
...

I thought I was a pretty good draftsman.
At least until I tried lofting hull shapes...
Buildings, machine parts, entire aircraft - no problems.

But fairing a hull can be a humbling experience.

Well, for grins and glggles, here are a few of my efforts so far.

http://www.home.earthlink.net/~cavelamb/draft.htm

Richard




Hi Steve,

Actually, I erased all the nail holes - trying to be neat.

Richard