After working on a clone of the Kopter Pterosaur on and off for a few months, I finally had a chance to fly it at last weekend's Saros launch.
The Pterosaur is a relatively heavy (4.4oz = 126g) D-powered rocket glider. It's about 28 inches long, with a delta wing whose span is 20 inches. The design ducts ejection gases toward the nose then back toward the tail. This pushes a balsa piston that releases an elevon.
I tried a D12-3 in it. Boost was nice and high, very straight, with a dramatic slow spin. Transition to glide was very smooth. The only evidence of transition was the sound of the ejection gases escaping. The glide pattern was a wide spiral, but kinda steep. It landed kinda rough, nose-first.
I remove some balsa from the shims I'd added to the elevon-stop surface on the rudder. And tried it again on a D12-3. Boost was identical to the first flight. This time the glide pattern shallowed out quite a bit. From far away, the glide looked kinda lazy, but close up... whoo, this baby really moves! Glide time doubled, too. The landing was much gentler this time.
The Kopter catalog displaying the Pterosaur (and other cool concept kits) is at Sven Knudson's Ninfinger site at
I've found the project to be quite challenging, with interesting parts to fabricate and lots of opportunity for careful fit and finish adjustments. The glider is kinda tricky to trim. I recommend shimming the elevon rather than adding weight to the nose or tail. You need a fair amount of wind when flight trimming.
Overall, I've found the Pterosaur to be a most satisfying build. It shows and performs most impressively, too.
My compliments to Mr. Senoski, for a fantastic design.
Dwayne Surdu-Miller SAROS #1