Final Presentation

The project built by the group finally was presented to the physics professors and this is the final result of the Catapult Trebuchet:

Picture 1. Final Presentation

Source: Own

Our thanks to:

• Prof. MSc. Rafael Bittencourt and prof. MSc. Targino Amorim, for all the help and monitoring along the project construction.
• Prof. Elenilson Nery, for the lessons about the theory envolved on the catapult.
• Vinicius Moura, a student of Mechanical Engineering, for the support on the catapult 3D model.
• All the monitors of physics lab of SENAI CIMATEC.
• José Augusto da Silva de Almeida, Integrated Management Manager, who helped on the catapult mounting and also gave tips on how to build the catapult.

Construction and Test of the Catapult

Catapult Construction

Next, the team met and started the catapult construction, following the steeps foward.

STEP ONE - Dimensions and weights of the projectile and the counterweight

 

STEP TWO - Verify the dimensions calculed and the designed structure

STEP THREE - Start to build the individual pieces

   

STEP FOUR - Construction of the base

STEP FIVE - Fixing the axis and the suports

STEP SIX - Construction of the arm overlapping the pieces and putting the central axis

STEP SEVEN - Building the basket for the counterweight

STEP EIGHT - Put all the sistem together and start to stick

STEP NINE - Putting the lifting sistem using a PVC Flange and pulleys

Note: Before tests, was observed by teacher that was fails in the arm, about the dimension and stability that the team had to fix. After the repairs, the dimension of the arm gone of 66,5 cm to 104 cm, and fails about stability were fixed.

Test video (Before fix the arm)

The video below are about the catapult before the arm get fixed, where the range was betwen 4 and 5 m, what is few, considering the dimensions of catapult.

  

Also, a video of the catapult test is available on Youtube, as the link below shows:

https://www.youtube.com/watch?v=rIxZPpM5lH4&feature=youtu.be

Test Video (After fix the arm)

The video below is about the carapult upgrade on the range, caused by the repairs on the arm.

 Test Video (Proof of the Launch Angle)

The video below is about the trajectory of the projectile in the moment of the launch and the angle which it leaves the catapult.

The Catapult Trebuchet

The video below is about the trebuchet catapult.

Budget

First of all the group members bought all the necessary materials, listed below:

Material	Amount	Cost R$
Packages of wood sticks (30 cm)	18	54,00
Durepoxi 50g	9	23,90
Wood Glue 250g	2	21,50
White Glue 1L	1	16,90
Wood Spoon	1	4,50
PVC Flange	1	9,00
Pulley (1 cm)	2	6,00
Total Cost		135,80

The cost and quantity of the sticks are high, but not all were used. Had to much waste building the first basket and with spoiled sticks.