Russ, how many time are you going to repeat yourself? WE get it, if you don't want to get involved, don't. If the Arc can hit sub 70KG weight, we can too, something may have to give, or we might have to get a little cleaver. If you have an idea other than plywood, I'd be happy to hear it.
--- On Wed, 3/21/12, russell wilson <This email address is being protected from spambots. You need JavaScript enabled to view it.> wrote:
From: russell wilson <This email address is being protected from spambots. You need JavaScript enabled to view it.>
Subject: Re: [Carbondragonbuildersandpilots] Re: CDII -fuselage
To: This email address is being protected from spambots. You need JavaScript enabled to view it.
Date: Wednesday, March 21, 2012, 8:37 PM
yer?..were talking about a 70 kg carbon dragon not an 80 kg ish magic dragon .....we are talking about replacing the wood d tube with carbon and trying to keep it the same weight....talk to steve again and ask him how thick his scin is and then calculate the weight diferance..wood to carbon will be...and ask him how heavy his magic dragon is.the filler and paint alone he has on his ship will tip the scales over 70 kg on a standar dragon most finished standard dragons are over 70 kg.... then add carbon with a density of 1.8 and he also has glass in his d skin dosent he?..density 2.6..resin 1 to 1.3
i think i have the following right....if you doble the thickness of a beam ..it is 8 times stronger and 36 times stiffer....i cant remember if the numbers are right.
if your goal is to have a dragon that weighs 70 kg or under and you are going to use carbon for a d scin then some thing has to give...what will it be?will you cut some thing off the aircraft? the wing tips?will you change the design?geodetic d scins?will you thin the d scin?will you go over 70 kg.or will you come back to wood.
my advice is to use what the plans call for..if you feel carbon is for you then make a carbon d scin that is the same thickness as the wood..ie a heavy d scin.....do not make the ribs hevier..do not weight the back of the wing.
the tempest is a 70 kg glider...a pilot lenthened the alerons to improve roll controll..it fluttered and killed him.
russ.
