I wanted you to know how the 1st of ESO B students managed to make technology works in Colegio Zuloaga. We have built so far 3 of 10 machines invented by Da Vinci. They are not too complex mechanisms (as it seems to me), made by plastic parts. First I will explain how we did the catapult.
The truth, is that we did not have any problems at the time of building it, because we followed the manual and it went pretty well. The two groups that I was with, did very well, our is an excellent class. The only fairly doubtful, was that a team mounted their catapult different to the other two groups, and we did not know which was the right way to do it. Finally, we saw that it was ours, because although their catapult was better, the instructions indicated it as we did.
Also it must be said that it wasn't so difficult to make this work, because we saw these technological foundations in class. I'm going to tell you everything that we have related in this proyect to the book and the class of José, our technology teacher.
Forces:
-Tension; the rope is subjected to this force.
-Compression; the pier to be supported in one piece, and compressed by another (at the top).
-Sheed; the pieces when snapping
-Bending; any elongated part fastened by both ends.
-Obviously stress force; nearly all the pieces subjected to some kind of force.
It is a shell, fixed structure with fixed-end and simply supported beams. It has pillars and columns.
It used a worm gear: This is a mechanism made up of a gear wheel that meshes into a worm gear on a cylindrical shaped drive shaft. This was moved with a fiddle crank system.
The catapult is a mechanism with:
-A crank system, you use this when you launch objects by the arm of the catapult.
-A worm gear: Similar to a rack and pinion system.
-A connecting rod mechanism; connected to the crank and the gear.
The only thing that I could add, is that I am impressed by all the technological foundations that the catapult has.
