Reincarnation of the Flying Flea into the Yellow Butterfly, although it still crashed

The problems with my flying flea so far appears to be: the short range of CG (usually it appears nose heavy but as this is complicated by the AOA of the forewing, it is kind of difficult to assess until it is flying), the securing of the 2S500mah battery (Mr. Grayson, the grey foam pilot couldn't put his back to the battery tight or long enough), the constant loosening of the wing actuating horn (so I have slop) and the general fragileness of the rigging lines which are a pain to re-install.

The two sets of forewing rigging lines of sewing thread has snapped. I the forewing rigging thread with 0.33mm fishing line (40 cents investment) because the sewing thread snapped frequently.

I tried to tackle is the short permissible-range of CG. I would prefer to distance the wings a bit more, to give it more moment arm, but there is not much chance with such a short fuselage. Instead, I glued on two sticks of tail, fabricated from carbon fibre rods and two oval discs of clear pvc sheet (book cover material) joined at the rear with a flat carbon fibre strip. This gives the planform an appearance closer to that of a butterfly. And since the model is sprayed yellow, hence, Yellow Butterfly. So it is not a flying flea then, but, let's at least get it flying.

I found I had to add a 5gm weight to the rear of this double tail (or third pair of wings) when the battery is in the cockpit if the model is to balance at the calculated CG point. So I made a hatch at the bottom of the fuselage, just behind the former of the cockpit and placed the battery there and removed the 5gm of leadweight. Seems a bit tail heavy but I like to try that because many taxi runs ended up nose-over, maybe the rear wing is lifting too much.

With the 0.33mm nylon line forewing rigging, slightly collapsed cabane (resulting in a lower forewing), transparent pair of third wings, and battery behind the cockpit backrest former, the model lifted off the ground wallowed in the brief seconds when it is in the air before snapping inverted and dived onto the ground. Clearly, a sign of rearward CG.

The model is broken again. The front cabane struts broke from the firewall, the starboard horn teared (including tissue) away from the foam wing.

Every crash is a re-build opportunity for improvement.

But maybe I will lay off Yellow Butterfly for a while and do up the RED 3D Butterfly (inspired by the Yellow Butterfly but with single depron foam elevon wing, deep fuselage and rudder). Another possible model I might make before I continue with the Yellow Butterfly is to do up a tandem wing flyer.

Concept for tandem winged flier
Take two chuck glider wings (18" span, 1/4" x 4" balsa, polyhedral for the front and dihedral for the rear), separated by a fuselage with at least 6" between the TE of the forewing and the LE of the rear wing, pair of elevons at the rear wing, with a rudder set 6" away from the TE of the rear elevon. Die, die must fly.