Introduction

Hello my name is Javier and I´m going to talk about the constructions that we have done in class of Technology. 

The constructions are miniatures of the inventions of Da Vinci. The projects are:

• A crane
• A catapult
• A assault ladder
• A wings

We have a few problems but they were nothing important so we can solve it quickly.

Now I´m going to talk about the Technical Process- here I will say the problems that we had, how we sort it out and how quickly we made the constructions.

 When I finish the Technical Process I will start with the Technical Stuff- in the Technical stuff I will speak about the objects that we use to construct each miniature.

The Crane

The first construction that we built was the crane. A machine use to raise heavy objects, to construct buildings.

We have a few problems at the beginning. At the end we have a very good miniature done. Later we did two appliances for the crane. 

We were very happy when we finished, although we weren´t the first.

The Catapult

The second miniature that we build was the catapult, a war machine invented by Da Vinci to break down the walls of the castles.

 We have a big problem in this construction, this problem was that we ``lost´´ a piece that we need to join the gear to the fulcrum (Supporting point). So we can´t solve it due this we do an appliance to make it work.

When we finished doing it we found the piece in the box of other group. 

The Assault Ladder

The third miniature was the assault ladder used to besiege the castles of the enemies.

This was a very easy project so we didn´t have problems so we finished very quickly and well done it.

The Wings

The fourth project was random (we can chose the miniature that we want) so we chose the easiest project of all these are the wings.

The wings were easy but when we were finishing we had a problem: the rope was to short so we can´t fixed in. We solve it doing the appliance sorter.

We were the last due this problem.

Levers

There are 3 classes of levers, depending on the effort force, the resistance and in the fulcrum:

•    In the first class lever, the fulcrum is located between the effort force and resistance. Characterized in that the effort force can be less than the resistance, although at the cost of slowing transmitted and the distance traveled by the resistance.

•    In the second class lever, the resistance is between the effort force and the fulcrum. Characterized in that the effort force is always less than the resistance, although at the cost of slowing transmitted and the distance traveled by the resistance.

•         In the third-class lever, the effort force is between the resistance and the fulcrum. Characterized in that the applied force is greater than the resultant, and is used when it is required is to increase the speed transmitted to an object or the distance traveled by it. 

Gears

A gear is a rotating machine part having cut teeth, which mesh with another toothed part in order to transmit torque.

There are different types of gears:

    ·        A Worm Gear

     o   Is made with a Driven Gear and a Driver Gear

    ·        A Bevel Gear

     o   Is made with a Driven Gear and a Driver Gear

Point representation gear shift in a spur gear.

About the Technical Stuff

Well, now I’m going to talk about the Technical Stuff. As I said before I´m going talk about the objects and mechanisms that have each construction:

• Levers
• Gears
• Resistant force...

Technical Stuff

Well now I´m going to start explaining the Technical Stuff of the crane.

The Crane

In the crane we used a crank rod mechanism (sistema de biela manivela) to move the crane. We needed a worm gear connected to a cable that goes to the top part of the crane to move the hook. Later we applied a tweezers to catch more easily the objects that the crane have to pick up.

The Catapult

In the catapult we had to use a few gears to hook the part that moves to the part that was fixed where we applied the force in the crank rod mechanism to move it. Also we put to cables one tense and other no so when it moves they change.

The Assault Ladder

 The Assault Ladder is a third class lever. In the Assault Ladder we also use a crank rod mechanism for raise the assault ladder as high as possible. To do this we had to put a worm gear mechanism to move up and down the gears were very big so we have to move the crank rod mechanism a lot to move a little bit.

The Wings

The wings have no lever. We need a few things to build it. there weren´t gears, there were only two cables join to a bar of metal that goes up and down to make it fly (like birds).