I used a slightly different method to make my plugs. I used the blue insulating foam you can buy at the home improvement stores, then used a hot wire to cut the shape using the plywood ribs as guides. Then I covered everything with sheet rock compound and like you did...sanded, sanded, sanded. Over that I put the heat shrink plastic that is sold to insulate windows. After you tape it down well and shrink it it makes a beautiful smooth shiny surface that is guaranteed to come off the plug.

I haven't been able to fly my Dragon as much as I would have liked. I have been rebuilding our tow plane that was in an accident last fall. The last two times I flew it though were a blast. This glider really does go up in bug farts. I had a six hour flight in March, and a 3.5 hour flight last weekend and had to work my way down. I've finally getting a feel for the controls. The way the mixer is designed gives the stick some quirks. At 0 flaps the roll control is more or less neutral, but takes more force than what is used on the powered aircraft I've flown. I don't have much time in sailplanes so maybe this is normal. As you apply negative flaps (for speed) the stick really wants to stay centered and takes more pressure to roll. It’s significant pressure at -5 degrees. It's just the opposite when going the other way (positive flaps to fly slow). As you move the stick to roll, the stick wants to go farther, increasing the more the stick is moved. It becomes noticeable at the first flap setting. At full flaps it is very pronounced and just feels weird. I've found that I'm only using the 5 and 7.5 settings and that works fine.

Another observation. If you are having to set the glider up every time you want to fly, you’ll discover it’s a pain in the rear. I made tthe fairings around the flapperon control arms pretty tight and I'm constantly damaging them during assembly. On version 2.0 I’ll pay more attention to setup when designing wing assembly.


From: Phil <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: Wednesday, June 19, 2013 6:22 AM
Subject: [Carbondragonbuildersandpilots] Phil's Carbon Dragon - progress...


Hi Folks,

Just thought you might like to see a short video of part of one of the leading edge mould plugs being fabricated.



I did try another method of making the moulds first (lining 'negative' formers with a sheet of 0.5mm polycarbonate) but I couldn't get the polycarbonate sheet to conform perfectly to the formers no matter how hard I tried! So... I reverted to using the old, tried and tested method of gluing blocks of polyurethane foam between 'positive' rib formers and sanding... sanding... sanding..!

I hope to cover the polyurethane plug I just made with fiberglass this weekend and perhaps even lay-up the carbon fiber in the new mould next week if all goes well.

Enjoy,

Phil.