It's a chicken and the egg problem. Your frames won't give you panels
unless they define a developable surface so unless you keep it simple and
are willing to do some trial and error, then spiling to the frames is
somewhat limited in value. The book you find most recommended (and there
are others, as Jacques and others pointed out, including an old mechanical
engineering text on drafting that I happen to own) is the book by S. S.
Rable. I believe it's still for sale. Look for "Ship and Aircraft Fairing
and Development." It's an older text so some of the terminology or wording
can be a little confusing but if you work the examples as you go through it,
you'll learn the process. I find it much less error prone to do the work
with AutoCAD rather than by hand ...pencil-width errors when doing the
necessary triangulation can add up to too much of an error when doing
complex plate expansions, but CAD uses exact calculations (measurements) and
the line width is has nothing to do with accuracy.

I disagree with Jacques on trying out Rhino 3D (around $1100). I mean I
agree a little, but disagree if you are planning on doing anything other
than a "look and feel" trial of Rhino. The surface techniques take some
time to learn if you are to get it right and can be darn frustrating if you
don't take the time to learn the ins and outs. The learning process
typically takes a number of months (like any good CAD tool). In summary
though, Rhino will let you define a surface and then constrain it to be
developable (conic sections, cylinders, flat) and can then unroll it to
produce flat panels that will work. You have to be careful with tolerances
too, else the panels will still produce gaps in the finished boat. Note
that Rhino is a general solid modeling tool, not really optimized for hull
design. ProSurf is fairly straight forward to learn and they let you
download it for free too. It *is* designed for hull development and has
tools that Rhino does not include that make the process easier and more
accurate. It's about $800, but the trial version will let you save 16 times
for free. If you are a student basically anywhere, I believe both outfits
will reduce their prices to around $300 though and that's for fully
functional software.

Brian


"Backyard Renegade" wrote in message
om...
"Brian D" wrote in message
news:Ro2Bb.270575$Dw6.918600@attbi_s02...
Scotty,

Don't be scared off. Buy some cheap 1/8" door skin and build a 1/4
scale
model. Use duct tape as your 'adhesive'. You'll find most errors right
off. Have some fun...

Brian

Seriously though, you will still have to take those fixes up to full
size, why not just spile the panels off the frame in the first place?
Scotty


"Backyard Renegade" wrote in message
m...
"Brian D" wrote in message
news:m9NAb.460002$Fm2.453789@attbi_s04...
Keep in mind that shell plate expansion (what you are doing by hand
and
with
software) is one of the more challenging parts of a hull design
program.
Even programs produced for more professional work, such as Rhino 3D
and
ProSurf, do not do a perfect job until you learn the ins and outs
and
tricks
of the trade to make it work right ...a key one being tolerance
management.
It's very easy to create an issue with tolerance stacking,
especially in
an
iterative calculation like what shell plate expansion uses. You can
nearly
always tell which designers actually built the boat they sell plans
to
or
not by how large the errors are in the panels. I've heard of errors
as
large as 5" in a 20' boat for example. Another key is management of
curve
complexity. In a developable panel, this primarily refers to the
combination of rate of change of curvature and also the tightness
(radius)
of the curves. To be accurate in such areas, the triangulation
(what
the
software is doing) either has to be very tight across the board or
vary
as
it goes. You'll find that every program is 'pretty good' to a
point,
then
once beyond that particular constraint, the accuracy drops off. Try
designing a boat with more gentle curves and see how it works out.
If
the
software allows you to define a measurement tolerance, then lean
towards
making it tighter, not looser. You can loosen the specs after you
have
a
finished panel that works, but don't do it in the calculation stage
(kind of
like not rounding off in precision until you report the final answer
with
the right number of significant digits.)

So, the bottom line is: take heart, your experience is not out of
the
ordinary. Look into the settings that Carlson makes available and
continue
to try different approaches until it all comes together.

Brian

"William R. Watt" wrote in message
...
Has anyone sucessfully built a boat out of unfolded panels from
this
hard
chine design program?

I just got my design for a 20 footer I am building back from the
engineer (who I had go over the design a one time). I designed the
boat in Carlson and was able to shape the bulkheads there. I was
thinking about expanding the panels out and building that way but the
more I read, the more I think I might just get them out the old
fashioned way.
Scotty from SmallBoats.com