We wanted our Bee Toy to have interesting mechanics and a duality of simplicity and complexity. We didn’t want it to look mean (like a wasp), or worse: cute. The concept was for the wings to flap when the abdomen (stinger) is pulled by using mechanics which would invoke curiosity and expose the moving components - to help a curious kid figure out exactly how the bee works.
After establishing these goals, we did loads of sketches, and dozens of prototypes. All things told; we tested over seventeen different options. During this process, the bee changed shapes many times (and occasionally drifted into wasp territory). At one point, when the bee seemed like it would be perpetually flat – I noticed that my four year old daughter had drawn a bee on a piece of wood she found in my workshop. It was wonderful (and strongly tempted me to acquiesce to a cute bee solution)! I wanted to understand what I liked about her bee drawing, so I took some time studying ways to transform it into a toy. While I was de-constructing her bee, my mind wandered to Luke Skywalker and I had the sudden idea to try an x-wing configuration for the wings – ultimately it was this change in perspective that helped the bee to have a more dynamic look – and more importantly the new form provided adequate room for the individual systems to function well together.
Arriving at the x-bee-fighter concept was only half the challenge, now we needed to work out the mechanics. 3-d modeling and geometric calculations helped, but ultimately it took a lot of trial and error, as well as analogue techniques (largely because of the tolerances in the manufacturing process).
Eventually, we arrived at a cool solution for the flapping wing mechanism which I’ll attempt to verbally explain below (but if my words don’t make sense, get your hands on a Tectonic Bee and it will become clear – especially if you take it apart): The bee’s sliding-actuated, flapping wing motion works by translating a y-axis force vector, into two x-axis force vectors, and finally translating these into rotational motion for each wing. These vector translations work through the use of strategically placed bolts which act either as pivots, sliders, or anchors. The first bolt is a long abdomen anchor which restricts motion of upper abdomen component to sliding along the lower abdomen in the y-axis only, and fastens the legs to the lower abdomen. A pair of bolts connects the individual wings to the upper abdomen. These bolts anchor the wings to the upper abdomen, but also allow them to pivot. There is a second pair of bolts fastened into the lower abdomen which project upward into the wing assembly. These bolts are stationary relative to the upper abdomen and wings (in other words the upper abdomen (and wings) can slide backwards, but these lower bolts don't). The lower bolts protrude into a curved channel in the bottom of the wing. The channel is a path for causing directional change; from a tangent in the y-axis to a tangent in the x-axis. When the upper abdomen (and stinger) is pulled back, it causes the wings to move backwards too, and as this happens, the fixed lower bolts drag against the side (x-axis) of the wing channel. This x-axis resistance, in combination with the wing pivot point which travels along the y-axis causes the wings to pivot forward and inward. It sounds complicated, but it is really just an arrangement of simple components.
The entire design process for the Tectonic Bee included many failed attempts (including avoidable things like filament running out during prints – or perplexing things like moving parts which work backwards (or are frozen)); but at each stage, we found added excitement about the progress and photographed each step of the way.