From: "Ugolini, Nick J" <UgoliniNJ@efdsouth.navfac.navy.mil>
Subject: RE: COZY: info
Date: Thu, 3 Jun 1999 12:59:40 -0400 

I have talked with some Berkuk? guys about their carbon canards planes.
They may be stronger and a bit lighter, but the ride is MUCH harsher (less
spring), more difficult to work with (antennas, finishing), and of course
more expensive.  The latest and greatest technology is not always the best
for the application.
 
Nick U

-----Original Message-----
From: Hunter Welch [mailto:nogofsu@sprintmail.com]
Sent: Thursday, June 03, 1999 3:15 PM
To: German Ferrer; cozy_builders@canard.com
<mailto:cozy_builders@canard.com> 
Subject: Re: COZY: info


Check out  the archives and FAQ's for about any topic you can think of.  Get
one of the books out there for comparison of different fiber glass and
remember that a Cozy isn't a Cozy if you deviate from plans
                                                                Bill W 

-----Original Message-----
From: German Ferrer < german98@cantv.net <mailto:german98@cantv.net> >
To: cozy_builders@canard.com <mailto:cozy_builders@canard.com>  <
cozy_builders@canard.com <mailto:cozy_builders@canard.com> >
Date: Wednesday, June 02, 1999 8:47 PM
Subject: COZY: info


Hi friends,
 
I am very interested in building a Cozy III, and at the moment I am
gathering 
information about the material type for the construction of the airplane, 
already all we know that the recommended material is the fiber glass but
exist in the market fibers more resistant and light like carbon fiber 
there would be some inconvenience in using  this material type in the 
construction of the Cozy?
 
Regards.
 
 

Date: Thu, 3 Jun 1999 14:59:52 -0500 (CDT)
From: Steven Eberhart <newtech@newtech.com>
Subject: Re: COZY: info


On Thu, 3 Jun 1999, Hunter Welch wrote:

>     Hi friends,
>      
>     I am very interested in building a Cozy III, and at the moment I am gathering 
>     information about the material type for the construction of the airplane, 
>     already all we know that the recommended material is the fiber glass but
>     exist in the market fibers more resistant and light like carbon fiber 
>     there would be some inconvenience in using  this material type in the 
>     construction of the Cozy?
>      
>     Regards.

I love working with carbon fiber but you can't just replace glass with
carbon.  Carbon is stiffer and stronger than the equivalent weight glass.
You can easily create situations where making one part stronger, i.e. a
wing, will place greater stress farther down the line, i.e. wing fuselage
joint.  You can actually end up reducing the point where the complete
assembly will fail by strengthining one part.  When making structural
changes you become the structural engineer and it is your responsibility
to do the failure analysis.  If this isn't one of your strengths then it
is best left to those that are.  Even after all of the calculations are
done Boeing still breaks a wing to verify that the calculations were
correct.

Just my .02 worth.

Steve Eberhart
-------------------------------------
http://www.newtech.com/nlf

One test is worth a thousand expert opinions but a thousand opinions are
easier to get.
       --plagiarized from an unknown author

All information, in any of my aircraft related correspondence, is strictly
food for thought and is in no way intended to imply that it is anything
more than ideas requiring additional, qualified, engineering analysis.

From: cdenk@ix.netcom.com
Date: Thu, 3 Jun 1999 16:55:04 -0500 (CDT)
Subject: Re: COZY: info

Was asked substitute carbon fiber. The entire airframe is a proven system with specific materials REQUIRED. Added strength per 
square inch is just part of the story! When disimilar materials are adjacent to each other they are subject to the same 
movement, one may reach its breaking point before the other. Try a cottom thread and a rubber band stretched the same amount. 
One will break much quicker than the other. This is one of numerous items to be considered. I am a structural engineer, and 
didn't substitute on the airframe. But my cowling and wheel pants are carbon fiber, patterned after numerous previous 
successful similar parts.

Date: Fri, 4 Jun 1999 18:51:06 -0600
From: James Russell <fshort@flash.net>
Subject: COZY: Re: COZY w/ carbon...

>Was said <you could duplicate their work>
>1: The ethical thing would then be to purchase the rights to the details
>used from all aircraft kits and plans used.
>2: The aircraft could not be called a COZY or a B...
>3: What would the weight savings be? and extra cost at $28.75/yd vs. $4.80
>per yard.


Hi:

Plus, add the enigineering costs...you might as well go to prepreg since
you're paying for restressing it ( 35% resin vs. 50% wet-layup )...add
freezer, oven, tooling, etc. I think 3 parts is the minimum ( break-even )
to tool up for... We are building one-offs of a proven design...Now you
would have a brand new design w/ all the debugging that implies...

Regards,
James


From: cdenk@ix.netcom.com
Date: Fri, 4 Jun 1999 17:21:50 -0500 (CDT)
Subject: Re: COZY: info

Was said <you could duplicate their work> 
1: The ethical thing would then be to purchase the rights to the details used from all aircraft kits and plans used.
2: The aircraft could not be called a COZY or a B...
3: What would the weight savings be? and extra cost at $28.75/yd vs. $4.80 per yard.

