Hi,
I am just curious about progress on Phil's carbon dragon. What is the status now? Have any major parts like the wings or pod been assembled?

Hi Tripp,

I had to down-tools for Christmas and have been very busy with other work since then. I aim to get back to working on my All-Carbon Dragon before the end of February.

I have fabricated all the internal ribs (wings, tail/rudder, H-stab/elevator, & tail boom) and managed to pull both halves of the tail boom from their mold just before Christmas (see the pics and videos on my project page.) My next task is to assemble the tail boom and get that major part finished. After that I plan to mold the various leading edges (wings, tail, H-stab), followed by the main wing spars before assembling the wings.

One of the reasons progress is a little slow (apart from work and other interruptions!) is that I am making significant modifications to the original design - each of which requires a fair amount of thought, design and load computation! The major changes in my CD are:

• I am building a 3-part wing,
• A removable tail/rudder (from the tail boom)
• A removable tail boom (from the pilot pod.)
• Cutting my main wing leading edges at 45deg from the root rib, either side of the pilot's head, to give the pilot a much wider field of view. The cutaway sections of LE will be skinned with 0.5mm clear polycarbonate plastic (the same as the pod canopy.)
• Replacing the delta-shaped spoiler with proper Hirth-Schempp air brakes
• I also plan to totally redesign the structure of the pilot pod... though I will be building the initial version of the pod more or less to the original specifications to get this beast into the air as soon as possible - refinements/redesign will come later!

I can't wait to get back into the workshop - I was really on a roll before Christmas!

All the best,

Phil.

Hi Phil,
Thanks for the response! I have been checking out your videos/photos on the website. You have definitely raised my interest in the possibility of all carbon construction, so I am keen on learning about how you are dealing with different issues. I certainly understand interruptions and the toll they can take on project timelines, especially with something as ambitious as what you are doing. I will check back frequently!

Regards,
Tripp

Hi Phil. I haven't taken a look at your pictures in a while. You're making nice progress!! A couple things I'd like to pass along. I remade the tow release after I started making the pod shell because the release would have ended up in a hole. I made the new mounting deeper and farther forward. I've attacked a couple pictures of the original and the new one. Also I had to rebuild the elevator pulley at the tail because I couldn't get enough "up" control. Part of the problem was my own making. I made my boom about 8 inches longer than the plans called for to help with too far forward CG problem most builders had. Because I extended it at the tail end the boom taper meant I had to redesign that piece slightly and it limited my elevator movement.

Hi Rick,

I had the same concern when I made up my first tow release, so I remade it so that it protruded a little further outside the fuselage skin. Now however I'm a little worried that it may not allow the tow ring to slip off the open forward jaw if the line is angled upwards (tow plane higher than the glider.) I think a slight re-profiling of the front jaw should solve this... but I need to do some tests. Happily I haven't bonded the kevlar skin onto the fuselage yet.

www.ihpa.ie/carbon-dragon/images/carbon-.../20140820_114855.jpg

I probably should have extended my tail boom (as you did) to overcome the CG problem but enthusiasm got the better of me and I built it to the plans. By way of mitigation I am building my H-stab and elevator with solid carbon/kevlar skins - I figure if I need to add weight back there anyway, then it might as well be structural! I built the tail and rudder with just carbon D-skins but I may re-visit them and skin them fully with carbon just for the added weight. The tail+rudder as they stand are a shade under 5lbs, so slightly lighter than the prototype!

I just finished covering the H-stab plug with fiberglass this evening and hope to get the carbon/kevlar lay up done next week.

I noticed you were covering the horizontal stab and elevator with composite...looks great! I wish I could see the progress in person.

I was looking through your builder list and the unknown builder you have there is Mick Roberts. He lives in England in the summer and Wallaby Ranch in Florida in the winter (the CD is located there). He has made some interesting mods to the glider including making it a T tail now. I'll take some pictures when I'm there in the spring.

One other thing that came to mind when I was looking through some of the builder pictures. It looks like at least one other person made the same mistake I made installing the rear wing mounting beam through the boom. It's not mounted perpendicular to the boom centerline as it would seem but tilted the same degree as the wings are mounted, 4 degrees I think. Not obvious in the plans...might save you some work.

Rick