| Realistically, I don't belong on this forum......
hopefully I'll gain some insights and ideas to make my
project better, easier, stronger, and lighter.
That is for you to decide, but I would suggest there is
reason enough to stay.
| The original question regarded ply construction
alternative for an HP hull, something Rob had not offered.
I presented the information I had with regard to my own
project (intended), without making judgments or any
intention of actually equating those specifications
directly, just to show what Woods had done. I do agree
that it seems excessive, and would suggest that Richard is
not by any means "expert" with foam core composite design.
That all is very reasonable. I read your post as
suggesting there was little benefit to II when the numbers
were ran, which did not match what I see.
| We have a number of suggested substitutions for foam
core to plywood, all of which differ, Rob's being by far
the lightest, though he offers it to substitute for the
plywood only, not taking into account the stringers.
Richard's figures replace both ply and stringers with 12mm
foam and 900/900 glass. This is obviously not a template
for reversing Rob's HP to plywood..... the result would be
rather absurd I think. It is simply information to file
away, and add to one's "body of knowledge".
I don’t see a problem. Rob’s Infusion plan is for designs
like his, that are way up the design spiral. Other
designers design for their designs. that's why I chose
Robs designs. They are lighter, cheaper, easier and faster
to build than anything comparable. If you find something
better let me know.
A thing that further complicates comparison is Robs Latest
build techniques are even ahead of the latest builds, as
the knowledge, skills and ideas iterate faster than the
boats are built.
Look at Steinar's WW hull vs his LW hull.
| I am only on this forum to learn what I can to help me
construct my boat of choice "efficiently". It should be
obvious that if one were to peel the hide off the boat in
question and lay it on the floor, while it would lay flat,
it would be anything but square. Both the top and bottom
edges would be curved, and not in a way that I am capable
of calculating based on the plans, and the bow and transom
ends would be angles that could not easily be laid out in
the flat. I do not yet have the plans.... Things are still
evolving. A plywood skinned boat is normally built by
fitting each skin panel in place over formers with
stringers. There will be no scalable drawings or table of
offsets to precut these pieces. What this means is that
while making a flat infusion of the hull sides is
possible, I am left with the need to create a template
that will lay flat so that I can infuse to the final shape
(more or less). The other alternative, which you no doubt
would agree is absurd, is to make a 30' panel and attempt
to trim to fit.
What, its not our good looks and engaging banter?
As to figuring out the shape of the flat, to bend to the
hull, if you HAVE to build a frame, to hang everything
off, then just mock up what you need. paper of some type,
perhaps, laid and cut as you need as a place holder of the
spot. then remove and get your measurements. I would guess
its close enough.
As I look at Robs designs, I see very simple lines. Your
picture has very complicated lines. I am not a Naval
Architect, but, if it was me, I would follow the upper
hull sides strait down to a flat bottom, probably at the
same depth as the drawn hull, with a low radius curve in
the corners. You know, like robs designs. Way simpler to
build and you can infuse the bottom in one simple mold.
Its not like you need a very specific hull line to get
your boat to go slow.
Look, just ASK rob. He loves talking about boats.
| The lower hull beneath the knuckle will be done in cedar
strip over temporary bulkheads. The stripped lower hull is
typically glassed outside, and removed from the form, and
glassed inside. Everything above that will be sandwich, as
per the option of building them with plywood. My
inclination is to use low cost "sacrifice material" for
bulkheads, and stringers as needed using the provided
offsets for the foam version which has 1/2" foam rather
than 1/4" ply. The actual bulkheads would be sandwich, and
would be inserted later..... perhaps not even in the exact
original locations and shape in some cases.
| Ideally, I would like to generate the data to allow
others to do the same thing.... A reference line and table
of offsets could allow someone else to duplicate the shape
on a melamine table. The design of the Eclipse hull does
not have the simplicity of the HP hulls that lend
themselves to "intelligent infusion", nor do I have any
intention of redesigning the boat itself.
Meh, I think it way simpler to build a simpler design. I
mean you are doing a custom boat. You might as well get a
custom boat.
|> Why not ask Rob for a design and total package price
to meet your Statement of Requirements?
| Rob is not in the business of designing cats
Bullshit! He has done cats. But is it gonna kill you to
ASK?
| and an HP does not scale to my requirements
realistically.
Bullshit! A HP will do everything you need, except be a
30' cat. It will do it cheaper, faster, and safer.
| Richard has offered me a solution that works for me in
the form of Sagitta built on Eclipse hulls
Bullshit! You want an Intelligent Infusion, because you
can see the wisdom in it, but your stuck using expensive,
complicated and slow techniques. If there is where you
wanna draw the line on compromise, fine. But it’s not what
you want.
| .... longer than I really want, but it will allow me to
easily have the mast where I want it, and leave me with a
huge cockpit. The fatter hulls offer greater displacement,
and if I build the upper works using infusion, I gain
more.
A fat ‘square’ hull all the way to a flat bottom has even
more displacement. Build the whole thing in infusion, and
gain it all, cheaper. or not. Up to you.