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<DIV>Hitesh, a couple years ago, the boys at Aeroslave had built an all carbon
fuse of one of their models. The fuse was extremely stiff and light. Don't know
if they ever flew it tho.</DIV>
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<DIV>There are some radio links available now that are not as bullet proof as
desired and an all carbon fuse could cause a problem, if the antenna is embedded
in the fuse. Running the antenna out to a wing tip is not a good idea because
then it would fly normal to the flight line. For maximum effectiveness, the
airborne antenna should fly parallel the flight line.</DIV>
<DIV> </DIV>
<DIV>Kevlar is substantially less expensive than carbon cloth. Kevlar has a much
lower modulus than carbon, which means it will not be as stiff (about a
five-fold difference, depending on grades). But it is far tougher in impact
which means it can take alot more abuse (equal thickness sections) than carbon
before cracking. Both materials in combination produce the better composite
since it would be a better compromise of properties.</DIV>
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<DIV>Kevlar absorbs vibration better than carbon does but carbon will stiffen
areas like fuse tails far better.</DIV>
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<DIV>For stiffness and lightness, it's hard to beat a total area vacuum sandwich
(TAVS) construction. A little thicker foam component as
Piedomnt used in their Temptation fuse, is better than the extremely
thin layer that CARF uses in their IMPACT models. If they used lightweight
Kevlar cloth as the outside skin of the TAVS, it would produce a very good
composite that would be nearly bullet proof</DIV>
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<DIV>MattK</DIV></DIV>
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<DIV> </DIV>
<DIV>In a message dated 3/23/2005 9:08:08 AM Eastern Standard Time,
hitesh@salt.ac.za writes:</DIV>
<BLOCKQUOTE
style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: blue 2px solid"><FONT
style="BACKGROUND-COLOR: transparent" face=Arial color=#000000
size=2>Hi,<BR><BR>I'm pretty sure that carbon fibre is cheaper or at least as
expensive as the<BR>kevlar used in latest designs. From my current fus, I can
tell that the<BR>kevlar sections are alot more flexible than the carbon fibre
parts which are<BR>really stiff. Is the inherent flexibility a good thing and
part of the<BR>design ?<BR><BR>Cheers,<BR>Hitesh</FONT></BLOCKQUOTE></DIV>
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