Fall 1998
Engineering Design Module
College of Engineering
Rowan University
 
THE CAN CRUSHER
SPONSORED BY THE DEPT. OF MECHANICAL ENGINEERING  
 

Instructor:  Dr. Anthony J. Marchese*
 
Department of Mechanical Engineering
College of Engineering
Rowan University
201 Mullica Hill Road
Glassboro, NJ 08028-1701
Email address: marchese@rowan.edu
Telephone: (609) 256-5343
Fax:           (609) 256-5241

Philosophy

The mechanical design module of Sophomore Clinic I introduces students to the process of engineering design, and guides them through the design of a real-world mechanical product from concept to completion as a means of practicing the steps and tools required by a typical design process.

In this engineering clinic module, students will also be introduced to Product Realization Process (PRP).  This process consists of a structured approach to different stages of engineering design involving 1) Conceptual, 2) Configuration and 3) Parametric Design.  The design module will guide the students through each stage of the design process in a team environment. Concepts from Statics, Solid Mechanics and other courses will be used and reinforced. Finally students have to build a working model of their design. During the course of this project, design teams are expected to follow the various design stages as outlined in this handout.

• Concept and Configuration Design 30%
• Parametric Design (detailed design) 35%
• Prototype 35%

• John Dixon and Corrado Poli, Engineering Design and Design for Manufacturing, Field stone Publishers, Conway, MA, 1995
• Stugart Pugh, Creating Innovative Products Using Total Design, Addison Wesley, New York, 1996
• Hauser and Clausing, The House of Quality, Harvard Business Review, May-June, 1988
• Robert Pirsig, Zen and the Art of Motorcycle Maintenance, William Morrow and Company, New York, 1974

 

Recycling is a meaningful and sensible approach to protect our environment and improve the quality of our life. As part of improving and increasing recycling efforts, you have been requested to design and prototype a can crusher device for use at home. The can crusher must be compact, efficient, inexpensive, easy to use and safe to operate. The crusher must be able to crush popular 12 oz. soda cans.  The can crusher must generate significant mechanical advantage such that an elderly or handicapped customer can perform the task of crushing a can.

Teams must "purchase" needed materials from the clinic team. In most cases, the clinic team will be able to provide precut materials. Students will have access to basic shop tools for at least one class period for fine-tuning operations. Approved materials and their cost are given in the attached list. Students can procure additional material only with prior approval from the instructor.

Recall that the engineering designer "applies various formal techniques along with proven scientific principles for the purpose of defining a device, a process or a system in sufficient detail to permit its realization."  In this clinic module, the engineering science principles of statics and solid mechanics will be applied during the parametric design stage of the Product Realization Process.   The principles of statics will be applied to determine the acheived by the can crusher.  The principles of solid mechanics will be applied to ensure that the design does not fail under loading conditions.

• Statics Example: Calculation of mechanical advantage
• Solid Mechanics Example: Analysis of a simple structure
  
  

Each team is expected to prepare a final design report. This report must contain the following information:

1. Engineering design specification (House of Quality)
2. At least three different conceptual designs (sketches)
3. Evaluation of each design and identification of a concept for detailed design (Pugh´s evaluation chart)
4. Configuration design (sketches)
5. Parametric design and engineering analysis:
A. static analysis,
B. mechanical advantage
C. stress analysis
D. etc.
6. Cost Analysis
7. Detailed AutoCAD drawings of parts and final assembly
8. Test results
A. Force vs. time curve
B. Measured mechanical advantage
8. The manufactured device and unused material
9. Confidential peer evaluation form

Due Dates:

Section 1: Thursday, Oct. 8, 3:30 pm
Section 2: Thursday, Oct. 29, 3:30 pm
Section 3. Monday, Oct. 5, 3:30 pm
Section 4. Monday, Oct. 26, 3:30 pm

• Write a detailed engineering design specification for this product. Draw a House of Quality to illustrate the correlation between customer attributes and technical characteristics.
• Generate several possible conceptual solutions. Each conceptual solution embodies one or more physical principles. Draw sketches and describe the physical principles used in each concept.
• Evaluate each design using Pugh´s method and identify one feasible design for detailed analysis.
• Draw sketches illustrating possible configurations for the candidate design. Identify the optimum configuration.
• Static analysis: Draw a sketch of the selected configuration. Draw the geometry. Show all dimensions. Identify all external loads. Draw a FBD. Calculate support reactions. Calculate the output force.
• Calculate the input and output range of motion
• Calculate the mechanical advantage.
• Perform stress analysis. Calculate:
• normal stresses of all two force members,
• shear stresses in all pins,
• bearing stresses at each bearing surface, and
• maximum bending stress in transversely loaded members.
• Compare to maximum allowable shear and normal stresses, assuming an appropriate factor of safety.
• Iterate this procedure by making changes to your system until you get an acceptable design, considering functional requirements, size and other factors.
• Make part drawings and bill of materials. Consider critical and non-critical dimensions and tolerances.
• Estimate the total cost of the product.
• Fabricate, assemble and fine-tune your product.
• Test your device, measure the forces, and compare the measured forces with your theoretical calculations.
• Discuss your results.
• Submit your report and prototype.