Tuesday, September 13, 2011
Leonardo's Giant Crossbow Challenge - First Sketch
The book about Leonardo's giant crossbow arrived,
See the book on Amazon
and also I found the original documentary from ITN Factual Television (2002), which was telecast in Germany by The Discovery Channel a few years back.
Very insightful. Turns out that da Vinci never built the thing, he only sketched it out for the Duke of Milan, Ludovico Sforza, sometime between 1482 and 1492. Interesting: He promised that it will shoot a 100 lbs (44kg) stone ball (roughly 12" or 31 cm diameter) 28 yards (25 meters) far, and a 10lbs (4,4kg) ball 280 yards (250 meters) far.
The ITN team had three months and probably more than 10 craftsmen to build the crossbow. I think they spent at least 100,000 Euros. A fail, in the end. The 20 lbs ball they used did not even fly 20 yards. Then the prod broke, so they gave up. Pathetic attempt, really.
Just for the fun of it, I ordered a 1:100 scale plastic model of the Giant Crossbow, can't wait.
Here it is on amazon
Anyway, I want to make a slingshot cannon that exceeds the ancient promise, and I want to do it in three WEEKS, not months. With hopefully just two assitants. For under 3,000 Euros.
This will be pretty much a variation of my previous slingshot cannon, with a few changes. I sketched it for the Tapefilm guys, who need to find a TV channel as a buyer (sorry for the German text).
- Length will be 7 meters total, 6 meters stretch.
- Four wheels
- 500 kg to 1000 kg draw weight (1,100 to 2,200 lbs)
- Adjustable shooting angle
- Ratchet like cocking mechanism (not enough room for a four arms "cross" winch)
If all goes well, this can be done before the winter kicks in (early November 2011).
My brother, who is a physicist, figured out that I will be able to shoot the 100lbs ball about 34 meters with 500kg draw. I absolutely can't wait to feel the earth shaking when that ball hits the ground!
Posted by The Slingshot Channel at 2:17 PM