Monthly Archives: February 2013
This is our first attempt to design and build an Ornithopter . But first , what exactly in an Ornithopter ? Well an ornithopter is any machine that mimic the flying mechanism of birds by flapping its wings . Ornithopter derives it name from the Greeks (from Greek ornithos “bird” and pteron “wing”) . Guess who was also fascinated by bird flight ? Yes , Leonardo Da Vinci was also a great fan of this flapping wing machine way back in the 15th century
Ornithopter | What material do we use
Most people would use balsa wood , but we will use straws to build our models instead . It is important to understand the design and mechanical constraints using models before we build one that can fly . So for our first model , the material needed will be
- Galvanised wires
Ornithopter | Observation and findings
Now we will need to build a bigger model to see things clearer . Since we know from the small model , things aren’t exactly symmetrical and this could pose severe challenges to the final design of a flying ornithopter .Here we focus on the turning radius and its impact to the flapping action of the wings
It seems that the smaller the radius , the smoother the flapping actions . With a larger radius , from the videos below , note how furious is the downward wing movement . It probably can create a lot more lift with such forceful downward movement but being a larger radius would also mean less symmetry , leading to more problems with balancing and flight . So we will need to strike a good balance between these 2 conflicting parameters .
Ornithopter | Design and assembly
In this design , we connect the conrods directly to the wing spars . This makes the design simpler and require less mechanical parts , unlike the previous design . This will also make the ornithopter more efficient . We still make use of straws , foams , galvanized wires and tapes for our models . Now the ornithopter is completed , with a wing and a tail added to it . Note that it is not symmetry in nature due to the V-shape conrods and the circular crankshaft assembly .
To reduce the degree of non symmetry , we use thinner straws , those that we get from Yakult drinks for kids . We added some beads at critical areas to reduce stress build up and a smaller diameter galvanized wire thickness
Ornithopter | what else is needed ?
The current ornithopter will not be able to fly . There are 2 major obstacles that we need to overcome . First is the speed of the flapping wings powered by the rubber bands . The addition of the foam wing reduced the flapping wing speed tremendously , due to its added weight and stress . Second is getting the ornithopter to glide due to the imbalanced in its construction and design . So though we have some ideas how an ornithopter works , we still have a long way to go to get a flying ornithopter up in the air