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Fellowship of the Gears
A creative journey embarked upon by Chait, Daniel and
Ashley
Defining the ProblemUsing a 3mm thick, A4 size, acrylic sheet to design and build a gearbox to transform an insignificant electric motor torque to pull a 10kg weight up a ramp.
Mathematics: Part 1 (required tension force)
Assumed and known values:g = 9.81 m/s^2µ = 0.5 (wood on wood)m = 10 kg
Load
Mathematics: Part 2 (output motor torque)
r
T
Wire that holds the load
Cross-section of the shaft
Assumed and known values:g = 9.81 m/s^2m = 10 kgMotor output (torque) = 0.060 g.cmShaft diameter = 6 mm
Design Concept (Ordinary Gearbox)
Pros:
- Simple construction
- Simple speed reduction
Cons:
- Long gear train
- Would require a large casing
- The proceeding gear has to be bigger
Design Concept (Planetary Gearbox)
Pros:
- Even distribution of load
- Capable of large speed reduction
- Higher torque capability
Cons:
- Complicated construction
- Require more than one set of planetary gears for this task
- Not enough resource to make more than one set
Design Concept (Compact Gearbox)
Pros:
- Compact size, efficient use of resources
- Efficient speed reduction
- Even distribution of forces
Cons:
- Complex design
How did we Generate Ideas?- Visual Brianstorm.
- Each member presented an Idea. Positives & Negatives
- Pugh Chart
- Backward Engineering- Known issues identified:
- Shaft Rotation
- Bearing Design
- Gears Overheating
- Laser Cutter accuracy
- Material limitations
- Gear knob designs
Criteria of a Good SolutionRelevance - solution fits problem
Correct, performs well, appropriate to constraints, can be done, safe to make and use, durable for the tests it will be put through
Novelty - being new, original or unusualFinds shortcomings, corrections, implications of changesExtends ideas to create a better solution, or starts again, solves a
different problem, generates new solutions
Criteria of a Good SolutionElegance - ingenious
Obvious, clever, aesthetic, entire, simple, suitable, sustainableGenesisBasis for, reuse as, or gives perspective of solutions, problem,
produces new criteria, conceptualises the problem in a new way
Comparison of Solutions
m = mass pulledg = gravityh = heightt = time takenV = voltage appliedI = current drawnD = longest length
Comparison of SolutionsConcept Performance Gracefulness Operability Harmonious
nessRecognition Total
1 2 2 4 5 2 15
2 5 4 3 3 4 19
3 4 4 5 4 5 22