The first photo is of the 3/4" span glider, the 3/8" winged boxkite and the scale Monarch butterfly kites. The butterflies used to have antennas with scale knobs on their ends, but unfortunately those got pulled off accidentally when I was re-doing the string attachment.
You can just make out the string still attached to the boxkite (actually what's called a "conine", a boxkite with added triangular wings. The construction is tissue with sticks made from a single strand pulled from some fiberglass cloth, then stiffened with C/A. I used a piece of square brass tubing as a mandrel for construction.
The smallest butterfly was the first one, and it is warped because I didn't use any fibers. The other ones use single filaments of Kevlar which were unraveled from a single strand that was pulled form some Kevlar cloth. The filaments were then laid up in both the spanwise and chordwise directions during construction to form a framework. These held their shape quite well. The butterflies were molded with a controlled airfoil shape, dihedral and trailing edge reflex. The black lines and white spots were painted with a sharpened toothpick, and are exactly scale, taken from a photograph in a book.
I made the string for all the kites by unraveling a single filament from a single strand of some very thin Nylon cord. The cord was originally made for the cable that carried the little pointer on the tuning window of an old-fashioned car radio. The cord ran between the pulley on the left on the tuning knob, and the pulley on the right on the variable capacitor. Making this single-filament string was extremely time-consuming and tedious, and in the end it was still too heavy and stiff for these little kites.
The second photo is of the first generation of "bedroom glider" models I made around 1968-1970 to test some aerodynamic ideas. I was in 8th grade when I started making those. The first generation airplanes had L/D ratios of anywhere from about 3:1 to about 10:1. The second generation models ranged from about 9:1 to about 20:1. The key to the improvement was something I discovered at the end of the first series. I'd been pushing the aspect ratios higher and higher in search of better L/D's, eventually going as high as 100:1. That model doesn't exist anymore, it was too fragile, and also tended to warp so badly that the results were inconclusive. The highest practical model in the series was the 50:1 aspect ratio model with the V-tail that you can see in the photo, positioned about in the middle of the mobile. It did have the highest L/D till that point. However, I then tried going to a very low aspect ratio as a control to the experiment, with the model at the top of the mobile. It has a 2.5:1 aspect ratio. Oddly enough, its L/D was nearly the same as the 50:1 model! I realized that in going to the lower aspect ratio I had also increased the Reynolds number and reduced the airfoil thickness by a huge amount, and that these completely offset the effects of aspect ratio at these small sizes. The second generation of bedroom gliders explored this discovery in depth, with spectacular results.
I later made these first 13 bedroom gliders into a mobile, which was used as part of the Christmas decorations for the Soaring Society of Dayton Christmas party in the Engineer's Club in downtown Dayton. We hung it in the main stairwell, and the air currents kept it moving all evening. It was a big hit, and became a regular feature of the Christmas party for quite a few years after that. Today it hangs here at home in my office.
The second generation of "bedroom gliders" was built in the early 70's, and resides in a box on my bookshelf. The lessons about low Reynolds number aerodynamics I learned building and flying these began forming the foundations of the knowledge that many years later helped found DJ Aerotech. I still use small models like these for proof of concept work today.
Don