1. Wilfredo Ruiz Jose Rosa Molina Keven Alvarado Pliable Writing Desk Shaft Final Report Machine Component Design Prof: Dr. Pablo G. Caceres

2. Description: ► Our mechanism design consists of the component that carries out the work to giving movement to the uper part of the student writing desks that are in the classroom. This system is necessary since there is limitation of space between writing desk, this disables to maintain this part fixed, like in the regular writing desks. We looked for the security and convenience for the users of our product. Between the requirements of the mechanism one is due to take into account that the design has supported part of the weight of the student and its materials

3. Pliable Writing Desk Mechanism

4. Above View

5. What is the unique part of your project?

6. Area Zoom

7. Why do you design this device, what is its application ? 1)The main application of this device is to use it if you have a room that you use to make conferences and you use as a classroom. 2)We design this device because is a common daily use mechanism for students. 3)Also it is an interesting foldable device.

8. What are the most important engineering considerations in your design? 1)COSTS 2)SAFETY 3)DEFLECTION 4)POSIBLE FAILS 5)CRITICAL POINTS 6)DESIGN FOR FATIGUE

9. What is the most challenging part in your project? 1)BEGIN WITHOUT ANY INFORMATION 2)ASSUME FORCES ( DECIDE HOW MANY FORCES ACTS IN OUR COMPONENT) 3) APPLY K FACTORS 4)THE MATERIAL SELECTION ( FOR WHAT WE WHERE DISIGNING FOR)

10. What is the weakness of your project? 1)The device could be over design because we do not know exactly the forces that the component receive. 2)Most of our data have to be assumed studying the student behavior at the classroom. 3)If the forces that the component receive are smaller, we could find a more economical material. 4)If the forces that the component receive are bigger, the material could fail.

11. What you learn from this project? 1)Applying the class material to a real device 2)Conditions of design 3)Material selection applications. 4)Design a device for fatigue possible failure.

12. Forces in Component ► Bending hacia arriba ► Torsion en el eje x Provocando en C Provocando en C ► Stress ► Shear Provocando en D Provocando en D ► Pure shear

13. Beam ► Beam ► Shear diagram ► Moment diagram

14. Deflection ► Beam ► Angle of deflection ► Deflection

15. Punto crítico C (excel): AISI 1040

16. Punto crítico D (excel): AISI 1040

17. MATERIAL SELECTION Longitudinal Wave Velocity:

18. MATERIAL SELECTION The selected material was Steel 1040 due to its mechanical properties; ej. UTS=620 MPa, E=200 GPa, Sy=550 MPa, etc. fulfilled the requirements established for this element. advantage due to his availability and cost. Although Aluminum 2024 presents/displays similars properties and a high availability was discarded because AISI 1040 has smaller deflection and I surpass to the A the 2024 in the factor of safety (nAISI=1.96; nAl=1.77)

19. QUESTIONS ?