Machine Design 1 group project AY 2022/2023
Project Title: Design of a rotary composter for residential use
Scope:
Design a rotary composter for residential use.
The composter must be optimized for use based on throughput anticipated. The device needs to be manufactured from a
TT$2000.00 materials and manufacturing budget. It should be designed to be lightweight, maintainable, and
manufacturable.
List of choices for materials:
1) Available on SolidWorks:
AISI 1020, AISI 304, AISI 4340 (Annealed or normalized), Chrome Stainless Steel, ASTM A36 Steel, Plain Carbon
Steel, 6061 Alloy, 3003 Alloy, 7075-T6 (SN), Gray Cast Iron, Rubber, Copper, Brass, Nickel, Titanium, Vanadium, Pure
Gold, Pure Silver,
2) Material properties/ material may not be available on SolidWorks: ABS, PPE, Oak wood, Mahogany, Pine Teak,
Pine, Cedar, Beech, MDF wood. (Material properties from any reference source/website other than SolidWorks need to
be cited).
Due dates and penalties
For every day overdue, 1% of the final course mark is deducted from the project. You must put, below the title page of
the report, the group name, individual names and ID numbers.
Marking Scheme
Phase 1 Marking Scheme (20 %)
Introduction (3 marks)
 Introduce the project and identify the roles of the team members (1 mark)
 Discuss the way forward in managing the project roles and responsibilities and how project risks will
be managed. (2 marks)
Literature/Patent review (6 marks)
 Review of 3 distinct but applicable designs (including the use of in-text citation with appropriate
format) (6 marks)
[All product/patent drawings must have labels and be adequately explained in the text]
Proposed Design (1st Iteration) (4 marks)
 3D drawing of proposed design(s) (3 marks)
 Description of the proposed design showing how weight is optimized and the design uniqueness.
Give reasoning if/why the budget is expected to be met (This may be based on estimating costs based
on material selection or manufacturing methods/processes involved). (1 mark)
Calculations (5 marks)
 Explain the appropriate loading and boundary conditions that are to be considered in calculations.
This includes the appropriate end conditions if any components are analyzed separately (2 marks);
 State the associated theory, assumptions and respective formulae for your proposed design (1 mark);
 Determine the maximum stresses for the application along with the appropriate design values; hence
determine optimum geometry for your design (taking design values and material selection into
consideration). In the event where the optimum geometry cannot be directly solved for, determine the
maximum stresses expected based on assumed geometry and determine if this is appropriate/
acceptable. (2 marks)
Referencing (1 mark)
 Proper referencing and in-text citations in Chicago Manual of Style (preferably 16th or higher) format.
(1 mark)
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Proper report format, spelling and grammar (1 mark)
Phase 2 Marking Scheme (30%)
Summary (4 marks)
 What improvements were made from the initial proposed design to facilitate increased comfort
and safety? (1 mark)
 What were your results/findings? (1 mark)
 Discussion on how the project was managed. What obstacles were encountered and how were
they overcome? (2 marks)
FE model (2 marks)
 Appropriate boundary conditions and loading. Use diagrams from SolidWorks to clearly show
what you are referring to (2 marks)
Design (2nd Iteration) (3 marks)
 Optimization and/or design improvement such as:
i)
to reduce stresses in high stress areas (e.g. the use of features to aid in the reduction of
stress concentration) or
ii)
The use of more appropriate sections. (1 mark)
 Design Requirement- sample iterative calculation that includes stress analysis and sizing,
choosing appropriate larger or smaller standard section and recalculation of stress based on
new selected section. Ensure all tables/ information used for are referenced. (2 marks)
Plots (stress, displacement, factor of safety, buckling) (12 marks)
1. Von Mises Stress plot (2 marks)
2. Buckling (1 mark)
3. Displacement (1 mark)
4. FOS and if acceptable (1 mark)
5. Indication by marker of maximum/minimum stresses/FOS (1 mark)
6. Readable Legends (1 mark)
7. Description of plots (1 mark)
8. Mesh Convergence study (1 mark)
9. Discussion of plots and results (3 marks)
Stakeholder assessment (2 marks)
 User assessment of design with respect to weight, aesthetics, and function. (2 marks)
Proper report format, spelling and grammar (2 marks)
Peer review (5 marks)
 Submission of hard-copy of correctly completed peer-review sheet to Lecturer (1 mark)
 Mark assigned based on peer review ranking and Lecturer findings (4 marks)
Extra Notes:
Upload documents in PDF format.
Notes on Calculations:
Simply ensure appropriate sections are used with respect to buckling calculations. The appropriateness may
be based on:
i)
ii)
iii)
The FOS
Calculated values in comparison to design values
The geometry (remember moment of inertia can vary depending on direction of loading and a hole
on one end may cause changes between Ixx and Iyy values). This may be considered but is optional
For the major component selected (to determine the maximum stress of); only show the hand calculations for
the last results obtained (sample iterative calculation). Ensure that the results for previously calculated results
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are still shown. These results should only be based on one selected type of selection regardless of what type of
section was calculated for in phase 1.
You are still required to show calculations for other components (if any), regardless of if it’s the same from
phase 1 or not.
Maximum deflection expected must be calculated and compared with stress simulation and also buckling
simulation if possible.
Notes on Mesh Convergence:
For Von Mises stress simulation of your selected major component:
Include (and show) all three course, medium and fine mesh plots, clearly showing if/where the mesh is
refined for geometric discontinuity. (Mesh refinement must be manually done if SolidWorks doesn’t
automatically do it. This can be by the use of mesh controls or H-type adaptive meshing method in
SolidWorks).
Only one mesh size needs to be Simulated for the remainder of components.
(These mesh plots must still be shown)
Use your own reasoning (as well as external content such as from the SolidWorks simulation handout) to
explain the results of how the maximum stress varied with different mesh sizes. Explain if it is as expected and
why.
Notes on Simulation:
Only SolidWorks-software simulations will be accepted.
Only Simulation of the final design is necessary. Simulations of previous design may optionally be done to
demonstrate improvement. This may be necessary in the case where your hand calculations can’t show the
improvement and there is therefore no way to validate that an improvement was accomplished other than
through Simulations.
Only one Von Mises Stress/ buckling plot of each component Simulated needs to be shown. Do not have
repeat plots of the same Simulation done with different mesh sizes (All the Mesh plots still need to be shown
for every simulation done).
User comfort and additional features such as rubber for handles and clips for devices such as spring-loaded
mechanisms do not have to be included in the Simulations.
For Buckling simulation:
The Load factor is analogous to your FOS.
The worse case mode shape needs to be used (i.e. the one that gives the lowest Load factor)
For those who use the normal Non-eccentric buckling formula, the FOS is given by a ratio of forces as opposed
to stresses. i.e. F=Pcr/Pmax, where Pcr is the calculated critical/ allowable load and Pmax is the maximum
expected load.
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Peer Evaluation Form for Group Work
Your name _______________________________________
Your role on the design team _____________________________
Your group number/letter_____________________________
Write the name of each of your group members in a separate column. For each person, indicate the extent to which you agree with the statement on the left, using
a scale of 1-3 (1=Best; 2=2nd Best; 3=3rd Best). Total the numbers in each column.
Evaluation Criteria
Group member name #1:
Attended group meetings regularly and arrives on time.
Contributed meaningfully to group discussions.
Completed group assignments on time.
Prepared work in a quality manner.
Demonstrated a cooperative and supportive attitude.
Contributed significantly to the success of the project.
TOTAL
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Group member name
#2:
Group member name #3:
Feedback on team dynamics:
1. How effectively did your group work?
2. Were the behaviors of any of your team members particularly valuable or detrimental to the team? Explain.
3. What did you learn about working in a group from this project that you will carry into your next group experience?
Adapted from a peer evaluation form developed at Johns Hopkins University (October, 2006)
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