The document discusses the design of a gearbox system to lift a minimum weight of 8kg 1m in height using a motor with specified torque. It determines a gear ratio of at least 30.1x is needed. Several iterative design concepts are considered, with a planetary gear system selected as the optimal final design due to its compact and efficient design. The initial design is a 63mm cubic structure using an overlapping planetary gear configuration to meet the project requirements within size constraints.

1. ‘Creative Journey’
Group XYZ
Rhys Morrison, Bryan Sito, Kevin Huynh, Samuel Warren

2. Understanding the Problem
Performance ‘𝑝’ = (𝑚𝑔ℎ/𝑡𝑉𝐼)*(𝑚𝑔ℎ/𝑡D3)
 Weight (m)(kilograms): 8 -> ??? Kg
 Height (h)(metres): 0.5 -> 1m
 Time (t)(seconds): As few as possible
 Max. Axial Length (D)(metres): Minimize as much as possible
 g = 9.8m/s^2 V = 6V I (nominal) = 2.6A
 Motor Torque (nominal) = 80g.cm

3.  Find output torque required on 6mm shaft to lift minimum 8kg weight
T = F.R = mg*0.003m = 8*9.81*0.003 = 0.23544N.m = 2400.82g.cm
 Compare to input torque to find required conversion for gearbox
 (Specification sheet) 80g.cm = 0.00784532N.m input torque
 0.23544/0.00784532 = 30.010 conversion needed
 Design a gearbox using standard gears to achieve required ratio
 Create iterative solutions to achieve maximal performance balance of weight and lift speed
without overloading motor or building to excessive size

4. Derive gear sizes, pitch circle diameters (hence effective radii) and ratios from construction
sketches

5.  18mm/8mm = 2.25 Gear ratio
 2.25^? = 31.01
 ? = 4.52 gear-downs required to lift minimum weight at listed motor performance

6.  Large axial length
 Loss in power
 Not efficient

7. • Driving gear(back) convert torque
into speed, and the speed again
convert into torque
• Not efficient
• A third, larger type of gear
• Greater ratio
• Size constraints

8. • Driving gear(back) convert speed
into torque
• The smaller(front) gear which move
along with the big gear then drive
the output gear
• Not efficient

9.  Planetary gear system

10. “Final” Initial design
• Overlapping gear
structure, highly
compact
• Diagonal placement
to reduce axial length
• Simple, repeating
design. Easy to
modify
• Cubic shape gives
maximum volume
with minimum side
length
• 63*63mm, including
side tabs
• (Motor mounting not
finalized)

11. • Top-down view of gearbox showing
alignment of gears.
• Significant room to play around with
• Slight separation of each gear to avoid
friction. Include small washer or spacer