1. Computer Aided Engineering Design Course
Disk-o-Poli Saw: Bringing the 1813 Disk Saw Into the 21st Century
María del Mar Aguirre Font
Efraín Hernández Rivera
Leslie M. Mercado Santiago
Elba M. Sánchez Santiago
Computer Aided Engineering Design Course
Dr. Vijay K. Goyal
December 1st, 2007
Dr. Vijay K. Goyal INME 4058

2. Agenda Background Literature Survey Problem Description Project Flow
Analysis
Final Design
Recommendations
Conclusions
Dr. Vijay K. Goyal INME 4058
Dr. Vijay K. Goyal INME 4058

3. Background Disk Saws Project Focus
One of the most useful home improvement tools.
Invented in 1813 by Tabitah Babhit.
Project Focus
Bringing to the consumer the opportunity to have a
multifunctional disk saw.
Fig.1 Example of wood works
Fig.2 Wood Closet
Dr. Vijay K. Goyal INME 4058
Dr. Vijay K. Goyal INME 4058

4. Literature Survey Existing Disk Saws and Sanding Machines PROS: CONS:
Versatile applications including cabinets, doors and many
other wood projects.
It can be adjusted for depth of cut, which minimizes kickback.
It can be adjusted to tilt up to 50 degrees in relation to the blade.
CONS:
It is not possible to cut the wood at angles bigger
than 50 degrees.
Many workers have to make a big effort when
carrying out these tools to the work place.
-- Workers can not finish the entire work quickly.
Fig.3 Ergonomic problem when using disk saws
Dr. Vijay K. Goyal INME 4058

5. Problem Description
To modify the existent disk saws, providing a second application.
The second application selected was a sanding attachment.
This was achieved through the Design & Analysis of a disk saw and a sanding machine components individually and uniting them will allow to the consumers:
Fast switching to the sanding attachment.
Reduce- # of steps & time due to the multifunction.
Reduce human effort required.
Dr. Vijay K. Goyal INME 4058

6. Final Remarks and Recommendations
Project Flow + =
Need 2 1 3
Generate Ideas
Final Design 3
Optimization
Structural Analysis
Cost Analysis
Analysis
Final Remarks and Recommendations
Conclusions
Dr. Vijay K. Goyal INME 4058

7. Optimization Analysis
Method: Lagrange's Optimization Method
Focus: To optimize the total volume of the shaft and gear.
Analysis of stresses to which the shafts are submitted to.
Fig. 4 Shaft to be optimized
Dr. Vijay K. Goyal INME 4058

8. Optimization Analysis (Ctd.)
Design Variables L D F
dgear b
All 4 design variables are the dimensions that define the shaft’s area Power Transmitting Shaft Diameter
Power Transmitting Shaft Length
Straight Bevel Gear Tooth Face Width
Straight Bevel Gear Pitch Diameter
Fig.5 Sketch showing design variables
Dr. Vijay K. Goyal INME 4058
Dr. Vijay K. Goyal INME 4058

9. Optimization Analysis (Ctd.)
Objective Function
Cuales son los valores de a, di, c Nh?
Dr. Vijay K. Goyal INME 4058
Dr. Vijay K. Goyal INME 4058

10. Optimization Analysis (Ctd.)
Constraints
Equality
Inequality
Verificar ecuaciones
Dr. Vijay K. Goyal INME 4058
Dr. Vijay K. Goyal INME 4058

11. Optimization Analysis (Ctd.)
Results
The dimension obtained from the optimization analysis comply with K-T conditions
Analysis gives us the following results:
*f(x)=1.77in3
Dr. Vijay K. Goyal INME 4058
Dr. Vijay K. Goyal INME 4058

12. Structural Analysis ANSYS Fig.7 Applied Forces (in red)
Fig.6 Meshed Product
Dr. Vijay K. Goyal INME 4058

13. Structural Analysis (Ctd.)
Stress and Strain Plots
Dr. Vijay K. Goyal INME 4058

14. Structural Analysis (Ctd.)
Deformation Plot
Fig.8 Ansys plot showing deformation
Dr. Vijay K. Goyal INME 4058

15. Cost Analysis **Miscellaneous: screws, bolts, nuts, etc.
Dr. Vijay K. Goyal INME 4058
Dr. Vijay K. Goyal INME 4058

16. Final Design
After perform all the analyses the resulting design of the Disk-o-Poli Saw optimized part looks as shown:
Fig.9 Optimized part
Dr. Vijay K. Goyal INME 4058

17. Recommendations Develop a more detailed analysis of: Materials
Stresses
Thermal implications
To make an ergonomic analysis of the handle.
To design a universal adapter.
Design the machine in such a way that it can be used to cut not only wood, but plastic and concrete.
Ergonomic analysis to achieve a model that fits comfortably any application, either cutting which requires an axial force or polishing which requires a downward pushing force.
Dr. Vijay K. Goyal INME 4058
Dr. Vijay K. Goyal INME 4058

18. Conclusions The Disk-o-Poli Saw will facilitate projects due to:
Minimize workers effort during their projects
Guarantee workers less time of work
Multifunction will lead to complete the wood work
Feasible in terms of cost
Dr. Vijay K. Goyal INME 4058

19. Acknowledgements God Professor Vijay K. Goyal Professor Ricky Valentín
Dr. Vijay K. Goyal INME 4058

20. Questions
Dr. Vijay K. Goyal INME 4058

21. Thank You!
Dr. Vijay K. Goyal INME 4058