Posted by Frank Minelli (myslo@…>)
Alan, I can subscribe to what you say, but take issue with the term “bulkl”, when applied to the layup in the Freedom 33 mast. (at least as it pertains to hull No. 32) In all of engineering there is the concept of safety margin. It is hard, however, to speak of a safety margin in that mast, when the thickness, at the greatest stress point, the deck level, is as little as .125 inches. Is it weight aloft that made them build it so skimpy, or do you think thate might have been some other reasons? You dont think there were cutting any corners, do you? regards, Frank
Boardwalk for $500? In 2007? Ha! Play Monopoly Here and Now (it’s updated for today’s economy) at Yahoo! Games.
Posted by Alan Kusinitz (akusinitz@…>)
My reference to bulk was not specifically
to thickness. However the strength of the mast comes from the carbon layers not
the outer glass and coating. I’m not a materials engineer and don’t
know how to gauge the exact strength or details of the construction. However
they did offer a lifetime warranty at the time so they must have believed they
had plenty of margin for error. I have not seen any evidence to the contrary.
On my masts when they were converted from
the wishbone booms a hole was made on the forward side to allow a tool for
tightening the gooseneck bolts. Visual examination of the interior of the mast
at this high stress point shows no sign of stress cracks or any additional
surface cracks then elsewhere on the mast.
I’ve put a fair amount of stress on
my masts in winds of 30-42 knots and have listened closely and not heard any
audible signs of problems either.
Alan F-33 Hull #51 1982
From: FreedomOwnersGroup@yahoogroups.com [mailto:FreedomOwnersGroup@yahoogroups.com] On Behalf Of Frank Minelli
Sent: Saturday, May 12, 2007 2:04
PM
To: FreedomOwnersGroup@yahoogroups.com
Subject: [FreedomOwnersGroup] Mast
issues
Alan,
\
I can subscribe to what you say, but take issue with
the term “bulkl”, when applied to the layup in the Freedom 33
mast. (at least as it pertains to hull No. 32)
\
In all of engineering there is the concept of safety
margin. It is hard, however, to
speak of a safety margin in that mast, when the
thickness, at the greatest stress point, the deck level, is as
little as .125 inches. Is it weight aloft that made them build it so
skimpy, or do you think thate might have been some other
reasons? You dont think there were cutting any corners, do you?
\
\
regards,
\
\
\
\
Frank
Boardwalk for $500? In 2007? Ha!
Play
Monopoly Here and Now (it’s updated for today’s economy) at Yahoo! Games.
\
Posted by michel.capel (michel.capel@…>)
I think the original Freedom masts were built so ‘skimpy’ because
the rig concept works with self-depowering masts, as Hoyt calls it.
The masts have to be able to bend under a certain amount of
windpressure. Further, the stiffness of the masts is not so much a
function of the wall thickness but more of the total diameter of the
masts. If they would have enlarged the diameter, the wall thickness
could even have been less. I think…
— In FreedomOwnersGroup@yahoogroups.com, Frank Minelli <myslo@…>
wrote:
Alan,
I can subscribe to what you say, but take issue with the
term “bulkl”, when applied to the layup in the Freedom 33 mast. (at
least as it pertains to hull No. 32)In all of engineering there is the concept of safety margin.
It is hard, however, to
speak of a safety margin in that mast, when the thickness, at
the greatest stress point, the deck level, is as little as .125
inches. Is it weight aloft that made them build it so skimpy, or
do you think thate might have been some other reasons? You dont
think there were cutting any corners, do you?regards,
Frank
Boardwalk for $500? In 2007? Ha!
Play Monopoly Here and Now (it’s updated for today’s economy) at
Yahoo! Games.