I have finally got my Christmas present built. It is a model of the "helicopter" designed by my engineering hero, Leonardo Da Vinci, way back in the 15th century. Actually, Leo called it an "aerial screw" and there is no record of his having built it. Leo was an ideas man. I had a bit of trouble building this model, all my fault, because I was in a hurry and didn't read the instructions carefully. I ended up with the holes for the drive shafts 180 degrees out of alignment and had to carefully pull lots of things apart and reassemble them right way round. Leo's plan was to have men pushing on a windlass to get the screw up to speed, when it would lift off and fly. I suspect that it would have been a short and wobbly flight. Mine is driven by a small bear winding a crankhandle. I can get the rotor up to a speed where it is blowing quite a down-draft but not fast enough to lift off. Cranking is hard work, so I had to take a bear-nap after the first trials and Mum took a picture of me. She thinks it is funny that I look so flat.
Labels: aircraft, heroes, models
# posted by Bart Bear @ 4:00 pm
