Re: Enlarging a Design
That would have been nice, Graeme, but I've been working overseas, in
a place where I had no access to Yahoo.
Howard
--- Inbolger@yahoogroups.com, "graeme19121984" <graeme19121984@...>
wrote:
a place where I had no access to Yahoo.
Howard
--- Inbolger@yahoogroups.com, "graeme19121984" <graeme19121984@...>
wrote:
>more.
> Hi Howard,
>
> IIRC you've been off sailing :-) Good to hear your comments once
>
> Graeme
>
> --- Inbolger@yahoogroups.com, "Howard Stephenson" <stephensonhw@>
> wrote:
>
> > (Been away for several months, but I've been reading the mail over
> the
> > last couple of weeks).
>
Hi Howard,
IIRC you've been off sailing :-) Good to hear your comments once more.
Graeme
--- Inbolger@yahoogroups.com, "Howard Stephenson" <stephensonhw@...>
wrote:
IIRC you've been off sailing :-) Good to hear your comments once more.
Graeme
--- Inbolger@yahoogroups.com, "Howard Stephenson" <stephensonhw@...>
wrote:
> (Been away for several months, but I've been reading the mail overthe
> last couple of weeks).
I've given away my plans for Spartina but I don't recall anything
particularly difficult about it. More time comsuming-yes but not
inherently more difficult. It certainly isn't more difficult than
expanding Bobcat by 25%. You will have to redraw the design, loft it
and develop new expansions. I don't think you would find it reasonable
to expand in all dimensions but only length but others can expound on
that aspect. You might want to check with Mr Bolger about
alternatives. Remember, Bobcat expanded is no longer Bobcat but an
unknown quantity.
Bob Chamberland
particularly difficult about it. More time comsuming-yes but not
inherently more difficult. It certainly isn't more difficult than
expanding Bobcat by 25%. You will have to redraw the design, loft it
and develop new expansions. I don't think you would find it reasonable
to expand in all dimensions but only length but others can expound on
that aspect. You might want to check with Mr Bolger about
alternatives. Remember, Bobcat expanded is no longer Bobcat but an
unknown quantity.
Bob Chamberland
--- Inbolger@yahoogroups.com, "txsailor37" <txsailor37@...> wrote:
>
> The Spartina is a beautiful boat, however the construstion technique is
> out of my league. I built my bobcat to resemble the "style" of that
> boat as much as possible in tac-N-tape(look at the photos in this
> groups photos).
> Catfish is not the same as Bobcat, the cockpit extends all the way out
> to the sides and goes all the way forward. It can be built in
> centerboard or keel version. I have studied this boat and it might be
> the right idea. But it will probably not be as pretty as my Bobcat.
>
> SO....if I expanded all of the dimensions by 20-25% would the pieces
> fit together??????????????
>
> BOBBY
>
>
>
>
>
>
> --- Inbolger@yahoogroups.com, "txsailor37" <txsailor37@> wrote:
> >
> > I recently finished my Bolger Bobcat and I absolutley love everything
> > about the boat's performance and appearance, with one exception. It
> is
> > too small to take the ehtire family out in. This got me to
> wondering.
> > is it possible to add say 25% to all of the measurements and build a
> > 25% larger boat?? I mean if I were to add 25% to all of the
> > measurements would the pieces even fit together?
> >
>
The Spartina is a beautiful boat, however the construstion technique is
out of my league. I built my bobcat to resemble the "style" of that
boat as much as possible in tac-N-tape(look at the photos in this
groups photos).
Catfish is not the same as Bobcat, the cockpit extends all the way out
to the sides and goes all the way forward. It can be built in
centerboard or keel version. I have studied this boat and it might be
the right idea. But it will probably not be as pretty as my Bobcat.
SO....if I expanded all of the dimensions by 20-25% would the pieces
fit together??????????????
BOBBY
out of my league. I built my bobcat to resemble the "style" of that
boat as much as possible in tac-N-tape(look at the photos in this
groups photos).
Catfish is not the same as Bobcat, the cockpit extends all the way out
to the sides and goes all the way forward. It can be built in
centerboard or keel version. I have studied this boat and it might be
the right idea. But it will probably not be as pretty as my Bobcat.
SO....if I expanded all of the dimensions by 20-25% would the pieces
fit together??????????????
BOBBY
--- Inbolger@yahoogroups.com, "txsailor37" <txsailor37@...> wrote:
>
> I recently finished my Bolger Bobcat and I absolutley love everything
> about the boat's performance and appearance, with one exception. It
is
> too small to take the ehtire family out in. This got me to
wondering.
> is it possible to add say 25% to all of the measurements and build a
> 25% larger boat?? I mean if I were to add 25% to all of the
> measurements would the pieces even fit together?
>
-Check out Mr Bolger's "Spartina". You would have to lengthen "Bobcat"
by more than 25% to get room for more people unless they were very
small. You would only be adding 5 or 6 inches to the cockpit. You
don't want folks on the "platform" aft. It is really not usable for
passengers or crew.
Bob Chamberland
-- Inbolger@yahoogroups.com, "txsailor37" <txsailor37@...> wrote:
by more than 25% to get room for more people unless they were very
small. You would only be adding 5 or 6 inches to the cockpit. You
don't want folks on the "platform" aft. It is really not usable for
passengers or crew.
Bob Chamberland
-- Inbolger@yahoogroups.com, "txsailor37" <txsailor37@...> wrote:
>
> I recently finished my Bolger Bobcat and I absolutley love everything
> about the boat's performance and appearance, with one exception. It is
> too small to take the ehtire family out in. This got me to wondering.
> is it possible to add say 25% to all of the measurements and build a
> 25% larger boat?? I mean if I were to add 25% to all of the
> measurements would the pieces even fit together?
>
I should have added to my previous post that I don't know what keel
and centerboard options are for the newer version of Catfish.
and centerboard options are for the newer version of Catfish.
Bolger eventually did a version of the Catfish with a deck and cockpit
like the Bobcat.
like the Bobcat.
--- Inbolger@yahoogroups.com, "txsailor37" <txsailor37@...> wrote:
>
> This redesign would be very similiar in size to Catfish, just a little
> wider. I like the cockpit and deck layout in Bobcat better than in
> Catfish. Catfish uses 1/4 inch ply as well, I do not think that any of
> the panels would be longer than 16' and for sure none of them would be
> wider than 4'. I do not think you would waste a whole lot more wood
> than when building Bobcat. I think I wouuld probably use the
> dimensions from Catcfish's rig and sail.
>
> BOBBY
>
>
>
> --- Inbolger@yahoogroups.com, "txsailor37" <txsailor37@> wrote:
> >
> > I recently finished my Bolger Bobcat and I absolutley love everything
> > about the boat's performance and appearance, with one exception. It
> is
> > too small to take the ehtire family out in. This got me to
> wondering.
> > is it possible to add say 25% to all of the measurements and build a
> > 25% larger boat?? I mean if I were to add 25% to all of the
> > measurements would the pieces even fit together?
> >
>
PCB&F have the Catfish design which is Bobcat with about a 25% stretch
in length. This might carry the family. Faster.
The original from either HH Payson, Instant Boats, or PCB&F
http://www.instantboats.com/catfish.htm
http://groups.yahoo.com/group/BolgerCartoons/files/Catfish%20Sailboat/
The updated version available from PCB&F
http://groups.yahoo.com/group/BolgerCartoons/files/Catfish%20Daysailor/
might be better for kids who would like to see the passing view more
as they sail. Perhaps not as good a camper.
Graeme
in length. This might carry the family. Faster.
The original from either HH Payson, Instant Boats, or PCB&F
http://www.instantboats.com/catfish.htm
http://groups.yahoo.com/group/BolgerCartoons/files/Catfish%20Sailboat/
The updated version available from PCB&F
http://groups.yahoo.com/group/BolgerCartoons/files/Catfish%20Daysailor/
might be better for kids who would like to see the passing view more
as they sail. Perhaps not as good a camper.
Graeme
--- Inbolger@yahoogroups.com, "txsailor37" <txsailor37@...> wrote:
> I recently finished my Bolger Bobcat... It is
> too small to take the ehtire family out in... a
> 25% larger boat??...
Here is a link for Catfish:
http://www.instantboats.com/catfish.htm
Joe T
http://www.instantboats.com/catfish.htm
Joe T
--- Inbolger@yahoogroups.com, "txsailor37" <txsailor37@...> wrote:
>
> This redesign would be very similiar in size to Catfish, just a little
> wider. I like the cockpit and deck layout in Bobcat better than in
> Catfish. Catfish uses 1/4 inch ply as well, I do not think that any of
> the panels would be longer than 16' and for sure none of them would be
> wider than 4'. I do not think you would waste a whole lot more wood
> than when building Bobcat. I think I wouuld probably use the
> dimensions from Catcfish's rig and sail.
>
> BOBBY
>
>
>
> --- Inbolger@yahoogroups.com, "txsailor37" <txsailor37@> wrote:
> >
> > I recently finished my Bolger Bobcat and I absolutley love everything
> > about the boat's performance and appearance, with one exception. It
> is
> > too small to take the ehtire family out in. This got me to
> wondering.
> > is it possible to add say 25% to all of the measurements and build a
> > 25% larger boat?? I mean if I were to add 25% to all of the
> > measurements would the pieces even fit together?
> >
>
This redesign would be very similiar in size to Catfish, just a little
wider. I like the cockpit and deck layout in Bobcat better than in
Catfish. Catfish uses 1/4 inch ply as well, I do not think that any of
the panels would be longer than 16' and for sure none of them would be
wider than 4'. I do not think you would waste a whole lot more wood
than when building Bobcat. I think I wouuld probably use the
dimensions from Catcfish's rig and sail.
BOBBY
wider. I like the cockpit and deck layout in Bobcat better than in
Catfish. Catfish uses 1/4 inch ply as well, I do not think that any of
the panels would be longer than 16' and for sure none of them would be
wider than 4'. I do not think you would waste a whole lot more wood
than when building Bobcat. I think I wouuld probably use the
dimensions from Catcfish's rig and sail.
BOBBY
--- Inbolger@yahoogroups.com, "txsailor37" <txsailor37@...> wrote:
>
> I recently finished my Bolger Bobcat and I absolutley love everything
> about the boat's performance and appearance, with one exception. It
is
> too small to take the ehtire family out in. This got me to
wondering.
> is it possible to add say 25% to all of the measurements and build a
> 25% larger boat?? I mean if I were to add 25% to all of the
> measurements would the pieces even fit together?
>
Here's a few more considerations.
1. Bobcat is a tack-and-tape design. Just lengthening it by 25% would
require a complete re-draw of the panel shapes.
2. PCB is very good at extracting the most out of 8x4 sheets of ply.
To scale up all dimensions by 25% would almost certainly require you
to either find some sheets of 10x5 sheets of ply (impossible?) or
scarf 8x4 sheets together.
3. Would you scale up the ply thickness by 25% too? This might or
might not be strong enough.
4. Would the internal framing be strong enough to withstand the much
greater load imposed by the increased weight and stability or would it
have to be re-designed too?
5. What about the mast and sailplan? These would need to be re-
designed too, not just scaled up.
I could go on, but you get the idea. Better to look for a new design,
in my view.
Howard
(Been away for several months, but I've been reading the mail over the
last couple of weeks).
1. Bobcat is a tack-and-tape design. Just lengthening it by 25% would
require a complete re-draw of the panel shapes.
2. PCB is very good at extracting the most out of 8x4 sheets of ply.
To scale up all dimensions by 25% would almost certainly require you
to either find some sheets of 10x5 sheets of ply (impossible?) or
scarf 8x4 sheets together.
3. Would you scale up the ply thickness by 25% too? This might or
might not be strong enough.
4. Would the internal framing be strong enough to withstand the much
greater load imposed by the increased weight and stability or would it
have to be re-designed too?
5. What about the mast and sailplan? These would need to be re-
designed too, not just scaled up.
I could go on, but you get the idea. Better to look for a new design,
in my view.
Howard
(Been away for several months, but I've been reading the mail over the
last couple of weeks).
--- Inbolger@yahoogroups.com, "txsailor37" <txsailor37@...> wrote:
>
> I recently finished my Bolger Bobcat and I absolutley love
everything
> about the boat's performance and appearance, with one exception. It
is
> too small to take the ehtire family out in. This got me to
wondering.
> is it possible to add say 25% to all of the measurements and build a
> 25% larger boat?? I mean if I were to add 25% to all of the
> measurements would the pieces even fit together?
>
Tex,
I'm not a boat designer, nor do I play one on TV. What I've seen from
knowledgable folks is that there is a rough rule of thumb. That is,
you can increase a boats LENGTH by up to 10% (by increasing the
bulkhead spacing) without interfering with the dynamics. This is just
a rough starting point, and is not always true. Some boats might be
safely increased more... or less. If you want to read what's been
written about the subject, you can search the archives here, and at
other groups: boatdesign, michalak, etc.
I suspect any designer will tell you that a 25% increase results in a
whole new boat. They're likely to direct you to another of their
designs that'd be a better fit, or ask if you'd like to commission a
whole new design, based upon your original boat. However, why
speculate when the answer is readily available? If you're serious
about the subject, a fax or letter to Phil Bolger & Friends would
likely elicit an informed answer.
Cheers,
David Graybeal
Portland, OR
"You can say any foolish thing to a dog, and the dog will give you a
look that says, 'My God, you're right! I never would have thought of
that'" -- Dave Barry
*************
I'm not a boat designer, nor do I play one on TV. What I've seen from
knowledgable folks is that there is a rough rule of thumb. That is,
you can increase a boats LENGTH by up to 10% (by increasing the
bulkhead spacing) without interfering with the dynamics. This is just
a rough starting point, and is not always true. Some boats might be
safely increased more... or less. If you want to read what's been
written about the subject, you can search the archives here, and at
other groups: boatdesign, michalak, etc.
I suspect any designer will tell you that a 25% increase results in a
whole new boat. They're likely to direct you to another of their
designs that'd be a better fit, or ask if you'd like to commission a
whole new design, based upon your original boat. However, why
speculate when the answer is readily available? If you're serious
about the subject, a fax or letter to Phil Bolger & Friends would
likely elicit an informed answer.
Cheers,
David Graybeal
Portland, OR
"You can say any foolish thing to a dog, and the dog will give you a
look that says, 'My God, you're right! I never would have thought of
that'" -- Dave Barry
*************
--- Inbolger@yahoogroups.com, "txsailor37" <txsailor37@...> wrote:
>
> I recently finished my Bolger Bobcat and I absolutley love everything
> about the boat's performance and appearance, with one exception. It is
> too small to take the ehtire family out in. This got me to wondering.
> is it possible to add say 25% to all of the measurements and build a
> 25% larger boat?? I mean if I were to add 25% to all of the
> measurements would the pieces even fit together?
Adding 25% to the outer dimensions would yield a boat that is twice as big as the one you have now. (5/4ths cubed is about two).
Dave Gerr pushes very hard for adding to the length of a boat since it gives more room and much better stability. (and higher marina fees)
Adding 25% to each dimension would be strange. The moment of inertia of the structural timbers (wales, chine logs, keel) would change. The material strengths would not. One can drop a mouse without damage from a height that would kill an elephant.
Roger
derbyrm@...
http://home.insightbb.com/~derbyrm
Dave Gerr pushes very hard for adding to the length of a boat since it gives more room and much better stability. (and higher marina fees)
Adding 25% to each dimension would be strange. The moment of inertia of the structural timbers (wales, chine logs, keel) would change. The material strengths would not. One can drop a mouse without damage from a height that would kill an elephant.
Roger
derbyrm@...
http://home.insightbb.com/~derbyrm
----- Original Message -----
From: txsailor37
To:bolger@yahoogroups.com
Sent: Sunday, July 23, 2006 5:41 PM
Subject: [bolger] Enlarging a Design
I recently finished my Bolger Bobcat and I absolutley love everything
about the boat's performance and appearance, with one exception. It is
too small to take the ehtire family out in. This got me to wondering.
is it possible to add say 25% to all of the measurements and build a
25% larger boat?? I mean if I were to add 25% to all of the
measurements would the pieces even fit together?
[Non-text portions of this message have been removed]
I recently finished my Bolger Bobcat and I absolutley love everything
about the boat's performance and appearance, with one exception. It is
too small to take the ehtire family out in. This got me to wondering.
is it possible to add say 25% to all of the measurements and build a
25% larger boat?? I mean if I were to add 25% to all of the
measurements would the pieces even fit together?
about the boat's performance and appearance, with one exception. It is
too small to take the ehtire family out in. This got me to wondering.
is it possible to add say 25% to all of the measurements and build a
25% larger boat?? I mean if I were to add 25% to all of the
measurements would the pieces even fit together?