Leonardo’s helicopter – model update
After receiving a great email from Joseph Harriott with a lot of detail about the aerodynamics, I thought I’d better let you know what I have found with the models. I have read in several sources that leonardo probably got his idea from a flying toy that has been traced back to about 100 years before Leonardo’s time. One can only guess at the way the toy was made, but it was likely to have been a version of a propellor on a stick or straw (perhaps bamboo). The email pointed out that IBM have built a version based on Leonardo’s drawing and he pointed me in the direction of the site related to the Pierre Gianadda Foundation’s Leonardo exhibition.
So to my version. Firstly, using an idea from a spinning top for propulsion, I made a basic model using thin dowel and cardboard. I tried using a disc with a slit cut and one side turned up and the other down – this resulted in a blast of air, but insufficient lift. then i added a further half circle and was quite amazed at the increase in lift. The model as shown lifts off for short hops. That is, it lifts itself clear of the launcher, rising about a foot or so (about 30cm) before landing on its point and falling over. I also tried considerably larger rotors cut from the lids of two pizza boxes, but found that there was too much inertia for the rest of the model, and I broke several strings, and then switched to fishing line – but that broke the main vertical shaft. So back to the original design, but I shall try larger ‘system cards’ for the rotor. I’ll let you know how I get on. Meanwhile – here is the basic model:
My model of Leonardo’s helicopter
Cheers
Jerry
