<br><font size=2 face="sans-serif">Hitesh...</font>
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<br><font size=2 face="sans-serif">There are! Aeroslave has delivered about 20 full CF fuselages(Aries and Entropy's). Check www.aeroslave.com for pictures. The reasons they are not so popular are several.</font>
<br><font size=2 face="sans-serif">First-The newer, wider designs require an "A" sandwich construction to be stiff (no -not strength) enough. This mean two fabric layers separated by a core. Unlike fiberglass, CF only comes in limited configurations. For RC planes two main tow (yarn) weights are of interest, "T-300" 1K and 3K. 1K tow =1000 filaments, 3K=3000 filaments. When woven into a "tight" fabric, the 1K fabric =<b>3.7</b>oz/yd and the 3K fabric =<b> 5.7</b>oz/yd. When fibers volumes are equal, you can expect a 3X increase in modulus when using CF instead of glass. The problems arise because the new planes such as the Symphony have a huge fuselage area. The "A" sandwich construction uses a<b> 3.2</b>oz glass fabric, AND take less resin to wet out, resulting in a lighter weight fuselage that is "Stiff Enough". So CF fuselage is not really needed.</font>
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<br><font size=2 face="sans-serif">Second-Fiberglass costs about $6/yd, 1K CF costs $75/yd, and 3K costs about $50 yd.</font>
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<br><font size=2 face="sans-serif">Third-There does seem to be a small amount RF interference requiring the the antenna to exit the fuse. To many pattern flyers, seeing an antenna outside the fuse is akin to seeing a plumber's butt crack....equally embarrising. BTW-my antenna hangs out......</font>
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<br><font size=2 face="sans-serif">Fourth-Most pattern flyers really do not understand composites and the use and advantages of CF, therefore they are not real concerned (other than being forced to route the antenna ouside-so they only see negatives).</font>
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<br><font size=2 face="sans-serif">At Aeroslave, we have confined the expensive use of CF to areas that have the biggest bang for the buck, the Nose of the fuse, the Chin cowl and the Canopy. The 3X stifness of CF allows us to build the Canopy and Chin cowl as solid laminates and still exhibit stiffnes and integrity, The use of an A sandwich design on such parts is possible, but much more fragile than a solid laminate. Solid laminates do not soak up fuel nor dent, nor damage easily. We also use a specialty unidiectional CF that has the stiffness of steel. We place this and the rear of the wing root, eliminating the need for a former. This unidirectional CF is 3X stiffer than the lower cost "T-300" CF mentioned above and about 10X stiffer than fiberglass. </font>
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<br><font size=2 face="sans-serif">Hopefully this answers your questions. <br>
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<br>
Gray Fowler<br>
Principal Chemical Engineer<br>
Composites Engineering</font>
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<td><font size=1 face="sans-serif"><b>"Hitesh Gajjar" <hitesh@salt.ac.za></b></font>
<br><font size=1 face="sans-serif">Sent by: discussion-request@nsrca.org</font>
<p><font size=1 face="sans-serif">03/23/2005 07:41 AM</font>
<br><font size=1 face="sans-serif">Please respond to discussion</font>
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<td><font size=1 face="Arial"> </font>
<br><font size=1 face="sans-serif"> To: "NSRCA" <discussion@nsrca.org></font>
<br><font size=1 face="sans-serif"> cc: </font>
<br><font size=1 face="sans-serif"> Subject: Why are'nt there any carbon fibre fuselages ?</font></table>
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Hi,<br>
<br>
I'm wondering why there aren't any full carbon fibre fuselages - is the<br>
reason weight, strength or radio interference ? If it's radio interference,<br>
would putting the aerial in the wing not solve it, and then making it<br>
pluggable. Just wondering.<br>
<br>
Cheers,<br>
Hitesh<br>
<br>
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