[bolger] Re: Micro started, and one question on lofting
Thanks guys. Now, I've drawn the expanded panels in a CAD using Bezier
curves and simulated both situations: loft one half panel at a time and
loft the two halves together. The most "curved" curve (grin), i.e. the
bottom one, is off of less than 1 mm close to the butt, so apparently
there's nothing to worry about.
A little trick I learned from Jacques Mertens: after drawing the curves,
squeeze them in horizontal (I used a factor of 10). Any unfairniness in
the offsets will show up easily as a bump. This is CAD lofting! Great.
I'm going to check all the curves and I'll keep you informed, but so far
the bottom curve seems just perfect!
Best, Pippo
curves and simulated both situations: loft one half panel at a time and
loft the two halves together. The most "curved" curve (grin), i.e. the
bottom one, is off of less than 1 mm close to the butt, so apparently
there's nothing to worry about.
A little trick I learned from Jacques Mertens: after drawing the curves,
squeeze them in horizontal (I used a factor of 10). Any unfairniness in
the offsets will show up easily as a bump. This is CAD lofting! Great.
I'm going to check all the curves and I'll keep you informed, but so far
the bottom curve seems just perfect!
Best, Pippo
"giuseppe 'pippo' bianco" <bianc-@...> wrote:
<snip>
If the lines across the butt are straight, no problem. If the lines
near the butt are very curvacious you will loose a little of that. For
my 2 cents, I'd loft the next station out on the missing panel, that
should pull things fair. I'd certainly put both sheets together to make
sure the lines meet fair anyway, even if I had to sneak out onto the
road some quiet 3AM morning.
<snip>
> Now, my garage is not long enough to loft the whole side of the boatin
> one time because two plywood sheets butted together are 6.2 meterslong
> ( about 21'), so I must work with one sheet at a time. The lines seem<snip>
> very fair, but the question is: would they have been any different
> around the butt if I lofted them for the whole length?
If the lines across the butt are straight, no problem. If the lines
near the butt are very curvacious you will loose a little of that. For
my 2 cents, I'd loft the next station out on the missing panel, that
should pull things fair. I'd certainly put both sheets together to make
sure the lines meet fair anyway, even if I had to sneak out onto the
road some quiet 3AM morning.
----- Original Message -----Sent:6. desember 1999 09:29Subject:[bolger] Micro started, and one question on loftingWhat do you
think?I think that is a great idea! But who am I to say - I did not bother using a batten to fair the lines of my family schooner. I just drew a straight line between all the spots. The hull sides and the bottom fitted perfectly.I build in the open and on very rough ground. All the panels were lofted and cut separately. One major problem was to butt join the panels without having an even ground to let the panels rest on. The microscopic inaccuracies will definitely not disturb the joy of sailing my self built little ship! I am looking forward to see and read about your Micro progress, Pippo! Great web site!Bjørn
Hi all - I'm pleased to tell that the construction of my Micro has
"officially" started on Saturday, december 4th, 1999. The Micro pages
will be updated soon.
Just 2 hours of work done so far with the valuable help from my son
Giovanni (6). I lofted the forward side panel after slicing a 2 cm wide
strip from one plywood panel to be used as a spline batten (works great,
and the circular saw is so fast!). After two hours my knees were
protesting though, so yesterday I asked my brother (former volleyball
player) a couple of knee pads. Hope they'll work.
Now, my garage is not long enough to loft the whole side of the boat in
one time because two plywood sheets butted together are 6.2 meters long
( about 21'), so I must work with one sheet at a time. The lines seem
very fair, but the question is: would they have been any different
around the butt if I lofted them for the whole length? I'll check with a
CAD program tonight, but maybe the solution could be temporarily adding
a 2' wide strip aft of the butt (when drawing the forward side: this
strip should be butted to the forward side when lofting the aft side) to
continue the fairing with a couple of stations back there. What do you
think?
By the way, this first experience of "lofting" w.r.t. the use of full
size patterns confirms to me that full size patterns are really a waste
of time and money, and may introduce errors!
Thanks, and best
Pippo
--
****************************************
Dr. Giuseppe Bianco
Centro di Geodesia Spaziale "G. Colombo"
Agenzia Spaziale Italiana
75100 Matera (MT), Italy
phone: +39-0835-377209
fax: +39-0835-339005
e-mail:bianco@...
****************************************
"officially" started on Saturday, december 4th, 1999. The Micro pages
will be updated soon.
Just 2 hours of work done so far with the valuable help from my son
Giovanni (6). I lofted the forward side panel after slicing a 2 cm wide
strip from one plywood panel to be used as a spline batten (works great,
and the circular saw is so fast!). After two hours my knees were
protesting though, so yesterday I asked my brother (former volleyball
player) a couple of knee pads. Hope they'll work.
Now, my garage is not long enough to loft the whole side of the boat in
one time because two plywood sheets butted together are 6.2 meters long
( about 21'), so I must work with one sheet at a time. The lines seem
very fair, but the question is: would they have been any different
around the butt if I lofted them for the whole length? I'll check with a
CAD program tonight, but maybe the solution could be temporarily adding
a 2' wide strip aft of the butt (when drawing the forward side: this
strip should be butted to the forward side when lofting the aft side) to
continue the fairing with a couple of stations back there. What do you
think?
By the way, this first experience of "lofting" w.r.t. the use of full
size patterns confirms to me that full size patterns are really a waste
of time and money, and may introduce errors!
Thanks, and best
Pippo
--
****************************************
Dr. Giuseppe Bianco
Centro di Geodesia Spaziale "G. Colombo"
Agenzia Spaziale Italiana
75100 Matera (MT), Italy
phone: +39-0835-377209
fax: +39-0835-339005
e-mail:bianco@...
****************************************