Hi Doug Thanks for your email. I am a little confused. You Say " If your not worried about total performance then go ahead and use carbon" ???? The reason i want to use carbon is is for its superior properties and was considering a lighter weight than glass. Also where multipul layers are required with glass that would not be the case in carbon. An immediate weight saving, and a stiffer structure. As you suggested with seats, spats etc.
In my intial email re Carbon i stated yes we understand Carbon is stronger than eglass. It was in the area of "Buckeling" i was particualy interested in if used for wingskins. Does its properties in this area exceeded eglass.If so I would then feel comfortable to use a calculated lighter weight than the eglass used in the premouled skins presently avalaible. Mark said he used Carbon weight of 5.85 ounce / yard (on the majority of his KR2) the same weight as if using glass in relation to the wingskins. And i presume a single or at least less layers than glass than glass in the other areas. Mark are your Carbon wing skins premoulded ??? A question re KR2 original plans. Is it correct the original plans of the KR2 show dynal sheathing as the nominated wing skin.Is this is the case, as i understand it. Dynal offers no structual bennefits only acting as a skin to paint.It also weighs almost nothing. Out of interest if dynal was / is used it would not be premoulded. What technique was used, was there a layer of thin foam underneath the Dynal. ??? Thanks for all you help and patience Regards, Tim, Australia t...@dodo.com.au ----- Original Message ----- From: "Doug Rupert" <drup...@sympatico.ca> To: "'KRnet'" <kr...@mylist.net> Sent: Thursday, February 16, 2006 4:02 AM Subject: RE: KR> Carbon Fibre Tim first of all you must decide the overall mission of your aircraft. Super fast, or what seems to be the norm with others on the list. First be advised that CF blocks all radio, GPS signals. That said, if you wish a clean exterior, low drag machine use carbon fiber sparingly. The forward boat ahead of the wing as well as cowl, wheel fairings and pants come to mind. If you're not that worried about total performance the go ahead and use carbon fiber BUT you best have a wad of cash, this stuff isn't cheap. Myself, I would use CF for the seat pan and especially the seat back and bulkhead at the rear of the baggage shelf. Why? Exactly those properties that make CF undesirable for internal radio antennas. Passive radiation from said antenna are not exactly a boon to ones health. Want an example? Lay your hand on the antenna and push the transmit button. Next day your hand will look like a football it will be so swollen. (watch the flame wars start over that statement) Much has been written regarding the use of Kevlar and its' difficulty to work with. However Kevlar's strength is not much lower than CF while it has excellent properties such as vibration reduction, superior strength, lower weight (than traditional e-glass) and excellent damage resistance. For my own KR I went with the composite boat method of construction. This does away with the outer plywood skin and replaces it with foam between all the boat formers and sandwiched both sides with fabric (be it glass, Kevlar or carbon fiber). The inner skin on mine will be of Kevlar since the overall finish is hidden away. The outer covering is S-Glass which is 30% stronger, 15 % stiffer and retains those properties up to 1500 degrees. S-Glass is finished the same way as traditional E-Glass so you can achieve a truly outstanding outer finish on the aircraft. Hope this helps with the carbon fiber issue. As to engines, well many have responded already but I don't know what a Jabaru sells for in Australia so I don't feel comfortable commenting on the issue other than the lighter weight of the Jab may necessitate using a longer engine mount to keep the CG with range. Doug Rupert Simcoe Ontario I have already tried 2 twice to acecess the information via KRnet Archives. For both Carbon Info and Jabiru 3300 info. Nil results. ! I read the instructions re wording to use still no luck ? Regards, Tim -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.1.371 / Virus Database: 267.15.7/259 - Release Date: 2/13/2006 -------------------------------------------------------------------------------- > _______________________________________ > Search the KRnet Archives at http://www.maddyhome.com/krsrch/index.jsp > to UNsubscribe from KRnet, send a message to krnet-le...@mylist.net > please see other KRnet info at http://www.krnet.org/info.html
