Ah, now there you've got me! I've been concentrating so hard on the wings and control surfaces that I haven't actually given much thought yet to the construction of the cockpit pod! Certainly the 1/4" marine ply panels used in the pod could be replaced with 5mm cf/foam sandwiches, but I haven't given much thought to replacing the wooden longerons, which need to be steamed to shape. I'll have to put my thinking cap back on for that! It might be possible to make a solid foam plug and carve/sand it to shape and use that as a mold for a monocoque hull, reinforcing it with foam strips here and there... but I need to think hard on that and look at where the launch/flight/landing stresses will be. Much to ponder yet!

Phil.

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From: This email address is being protected from spambots. You need JavaScript enabled to view it. [This email address is being protected from spambots. You need JavaScript enabled to view it.] On Behalf Of Rick Mullins
Sent: 03 February 2012 01:05
To: This email address is being protected from spambots. You need JavaScript enabled to view it.
Subject: Re: [Carbondragonbuildersandpilots] "Carbon" Dragon?




After finishing the tail pieces I started eliminating much of the wood. My wing main spar and leading edge are composite and I wish I had done the mid-span ribs with foam and spruce or ply capstrips. If your goal is to replace all wood, I will be interested to see how you build the pod. I gave it some thought and decided to build the basic structure per the planes with spruce, and replace the bottom doors and outside plywood with a one piece molded Kevlar skin. I uploaded pictures of it. It seemed to me that to make it all composite would have required making many molds and re-engineering the controls and this seemed easier. Maybe for the next one .

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From: Philip Lardner <This email address is being protected from spambots. You need JavaScript enabled to view it.>
To: This email address is being protected from spambots. You need JavaScript enabled to view it.
Sent: Thursday, February 2, 2012 11:29 AM
Subject: Re: [Carbondragonbuildersandpilots] "Carbon" Dragon?




Hi Kenny,

You'll find a copy of your spreadsheet in the last tab/worksheet of my own spreadsheet of calculations, which is in the files section of this group - link below. I've updated my spreadsheet to tidy it up a little and to add my load/stress analysis of the ribs. I'm not sure how to do a load/stress analysis of the H-Stab and V-tail/rudder... but I have a feeling the loads are not big. Any advice would be appreciated!

I am planning to eliminate all the wood from my build and fabricate purely out of carbon fiber and foam. I successfully completed a load test of a root rib constructed out of 5mm foam (to 8g / 32kg) and am just starting to build a second root rib out of 10mm foam (with narrower caps and internal struts than the 5mm one) for a weight/strength comparison. I'll post the results shortly - I got a bit delayed while I got myself set up for using the resin infusion method rather than the wet hand lay-up I used on the first test piece.

Phil.

groups.yahoo.com/group/Carbondragonbuild...iles/Phil%20Lardner/

Direct link to file: f1.grp.yahoofs.com/v1/ALMqT3nGUcpm3vTxJR...201%20Feb%202012.xls