EPP, Carbon, Coroplast thermal ship DONE!

[CactusJackSlade]

I've finished my EPP, Coroplast and carbon fiber 2 meter (82") thermal ship.

I had to delay this posting because on it's maiden flight I managed to speck it out, did a dive test and had it EXPLODE at about 700 feet AGL... I managed to find all the pieces and since it's EPP I already have it all back together.

Now that I fixed my structural design failure and have flown it now in both slope and thermal conditions I can say it flys great.

"complaint" is that I shortened the boom a considerable amount in effort to cut down on nose weight to get proper CG. Due to the short tail moment it tends to waggle a little bit at lower speeds and yaws a bit when starting a turn, so I have to add a bit more than desired rudder along with the ailerons to get a smooth turn.

I may decreace the V tail angle a bit (more vertical) to help this waggling a bit?? I could also just increase the boom length and use a lighter boom and tail feathers. (balsa instead of Coroplast)

It flys well though, once in a turn it stays there and if there is any lift at all will go straight up.

This is a full house ship and I love the crow mixing. On one landing it literally hovered down to me.. cool, just what I wanted!

You can see some construction photos here: http://hobiehawk.com/EPP2MTD.html

Why di I go to all this trouble?... well just because no one makes a kit like this!

Hope this has been entertaining!

CJS

[CactusJackSlade]

OK,

Here is it's maiden flight... about 700 feet AGL... the blob on the lower left is a hawk that checked me out prior to my "expolosion"

Interesting note: The Hawk came SCREAMING in at me in a very aggressive posture... backed off, circled with me a few times then flew off.

In this area I have seen Hawks being VERY territorial, I think he was going to give the the "what's for" then decided I was an ugly bird that didn't deserve his time... ??!

[CactusJackSlade]

Well,

That is the deal with "backyard" engineering. Without REAL drawings, I did not realize how much I had weakened the nose pod area just in front of the wing... it had a boom channel, 2 servo wire holes and a lot cut out for the wing to fit... so....

As I did a high speed test dive to check nose up or down tendancies the nose pod flexed downward, then gave way allowing the front wing capture pins to come free... not only was the nose snapped off but the wing went from vertical to STOP in an instant (breaking one of the wing spars)... All I heard was a "CRACK" and the plane exploded.

Actually I just kind of went Hummm... and did not freak out (like if it were a molded ship!) It was so high up I had time to reach inside my coat pocket, take out my camera, turn it on, zoom it in and take a photo of the plunging fuse.

The fuse took about 20 seconds to hit and the wings took about 50 or 60 seconds to reach the ground! Fortunately, as I mentioned I found all the pieces and was back together in no time.

Here is the "plunge" photo:

CJS

[evan]

Very cool CJS, I've always wanted a foamie glider due to my flying skills (or lack of them) keep the updates coming.

[CactusJackSlade]

Just FYI,

I use a cheapo altimeter watch I got on eBay (about $35) to verify my altitude stuff.

It's very handy and fun to use when you are thermaling and speck out a glider... you can confirm how high you were!

Here is a photo of my wireless video set-up on "Orange UnCrushable"... but you can see my Alt watch strapped on as well.

CJS

[John Gallagher]

What is the flying weight of your plane? The Highlanders were coming in at about 37 ounces full house. Did you beat that?

John

[CactusJackSlade]

John,

My all up weight is 38 oz. The added weight is due to extending the wings 4", making them 2 piece (I think this is where a lot of the wing weight increased) and adding some CF the full length of the spar. I also added more strapping tape than recommended because I wanted it to be SMASH PROOF! I also used metal gear servos throughout and a large 1800 AA mah battery pack.

The boom is also heavy, even though it is carbon fiber it still weighs about 60 grams... about twice what I wanted it to be, but hey, it's pretty much bullet proof!

I think I could easily build it up around 34 oz if I kept to my senses and made it a 1 pc wing. It flys well though... I am hoping for some sun tomorrow so I can hi-start it for the first time.

Thanks for your interest!

CJS

[John Gallagher]

Is this a prototype for a future commercially available glider since MAD aircraft is out of business?

[CactusJackSlade]

John,

I had considered a kit... but I need to earn a living and even very successful foamie companies have a hard time these days... DAW is a good example.

I was however thinking of maybe some plans... too bad I am not proficient in CAD.... If I did a set of plans I wold put up a post!

Thanks for the interest... on the flip side I did quite a few photos on my construction page... you could duplicate it with a little work...

I di fly it again today (no bungie launch yet) and it again did very well... it was probably only 15% lower in max altitude than my molded 2M Whisper in the same conditions... pretty good for a foamy, especially considering I had a camera strapped to it most of the time!

Here is a photo of what I take photos with!... I'm sure it adds a bit of drag... plus I usually tape on my altimeter watch so it's not that clean when I'm messing with photo stuff..

CJS