C'mon ...you're making me feel bad about all that money I spent!

Brian

PS: Your method guarantees fit. Can't argue with that, eh?

"Backyard Renegade" wrote in message
om...
"Brian D" wrote in message
news:MClBb.486707$Fm2.472295@attbi_s04...
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



I am extremely proficient with several CAD programs, will not bore you
with resume'. But when I build my smallboats I mostly find myself
building the boat and getting out the panels the old fashioned way and
then later put them to cad, and then only for repeatability. I start
with bulkheads, sometimes run chine seams, and then make cheap
templates or use a spiling plank to get the pieces out, one time, full
size, even for small stitch and tape boats.

The boat I am finally building for myself, some of you may remember
discussion of a 20 foot skiff, will have 6 planks. I designed it in
Carlson Hulls, mostly so I could get a 3D look at it and some simple
numbers to compare as I shaped the hull. Eventually though, when I
build it, I will probably revert to more traditional ways of getting
out the planks once the station molds/bulkheads and seam battens are
in place.

Let's say it takes the average person 8-12 hours solid time to learn a
new program to the point where they can use it to get out panels, and
then say another 4-8 to either design or transfer over a boat hull and
spit out those expanded panels. You have 16 hours in and you have cut
nothing and these time guestimates are all probably very low as these
software programs are mostly directed toward those with formal
drafting experience/education. Remembering that I am talking about a
simple 6 plank 20 foot boat, (and Santa is not likely to bring me a
CNC machine) I dare say with a few sheets of luan or some battens,
ruler, pencil, skill saw, and a good days work, I could already have
all my panels cut out. No fancy software, no $800 pricetag, just some
basic math and a little common sense... I dunno, I am still not
convinced, Scotty