Monday, March 7, 2016
Leonardo Da Vinci's Mechanical Dragonfly
The box says "Mechanical Butterfly", though its description and appearance are that of a dragonfly.
From the Instructions"
Da Vinci was the first person to apply himself to the study of animal flight and human flight with such passion. Throughout his life da Vinci dreamt of building a flying machine which would enable man to fly. In spite of being unable to fulfill this task, da Vinci has the distinction of being the first person in the history of human flight to study the subject from a scientific point of view, investigating every possible solution. He even devised plans for muscle powered flying, where the pilot of the machine trys to replicate the beating of a birds wings, gliding, without moving the wings, and mechanical flight, where the machine flies without a pilot but only thanks but only thanks to the movement of mechanical parts like gears and wings. In his manuscripts da Vinci drew many contraptions, not all of which need a pilot. Many flying machines are preliminary studies, where most of the time da Vinci tried to imitate the anatomy of an animal; a bird, a bat, or an insect, such as a dragonfly. One of the projects for a flying machine with no pilot is the mechanical dragonfly,on folio 1051v of the Codex Atlanticus. da Vinci himself advised where one can admire admire these incredible flying insects: To see four winged flying, look near ditches and you will see dragonflies. It is extremely difficult to create a mechanical replica of the natural movement of an animal. The beating of the dragonfly's four wings is particularly complex and da Vince was well aware of how difficult it would be to create this machine. he himself described it in great detail. It is not simply wings beating up and down; it's a jointed motion. Whilst beating down the wings are "flat" in order to push as much air as possible, whereas when they are raised, they are angled so that they create less resistance. If the dragonfly and therefore da Vinci's machine, was not like this, it would not be able to fly because the power created when the wings beat downwards, would be canceled out when the wings returned to their starting point. Da Vinci wrote: The wings must return to the top very quickly, whereas pushing backwards with the part of the wing which pushes the air must be done at the speed required by the engine each individual time. The movement of each four wings is synchronized with the others. Da Vinci resolved the problem by designing to pairs of wings, one for the front and one for the back, exactly as on a dragonfly. When the wings are beating, the pairs of wings around their main linch-pin. The energy of this movement is provided by two spring loaded motors which drive a mechanical system made by gearwheels, a camshaft and connecting rods which in turn allow the pairs of wings to move alternately and in synchrony. Whilst the wings move more quickly up and down pushing the air, rods of exactly the right length fold the wings downwards ensuring they are angled when they come back up, exactly as it happens in the animal movement. The mechanism is very delicate and in order to make the machine work correctly it must be very fine tuned. Furthermore, the power the motors were able to supply would definitely not have been sufficient to lift the machine off the ground. In spite of this, the machine plan is absolutely fascinating and even if they are too slow, the wings move exactly in the same way as a dragonfly's.