This document discusses the design of a gearbox to maximize lifting power using limited space and materials. It considers using planetary gears but finds the design too complex and difficult to construct. The proposed design uses a series of spur gears inside an acrylic housing. Key features include using spacers between gears to reduce friction, optimizing gear shapes to reduce inertia, and pinning and gluing gears for strength and alignment. Testing will be done to evaluate the efficiency of the final design. The gearbox aims to maximize lifting power using multiple gear reductions within the strict space and material constraints.

1. Creative Journal
HUYNH LE, HAYDEN BURKE, JARRYD SYMONS, ASAHDULLAH FAHIM.

2. Introduction to the problem
Our understanding the core problems face in this situation:
We are required to lift a mass (m) a vertical distance of (h) with the aid of an acrylic
gearbox attached to a small motor in such a way that maximises p which is equal to;
𝑝 =
𝑚2.𝑔2.ℎ2
𝑡2.𝑃.𝐷3
Secondary issues (through brain storming) : Size restriction, material strength, stress on
gear teeth, surface resistance, maximum allowable acrylic usage (A4), friction within the
system.
From here we look at all possible gear types and configurations they could be arrange in
to optimise p.

3. Planetary Gears
Advantages
Large reduction ratio
High power density
Compact size
Disadvantages
Complex in design
Accurate gearing needed
Low tolerance for error
Relation to the problem
• Reduces axial length with compact size.
• The planets share the load rather then one gear.
• Reduces 9000Rpm motor to tolerable level for material

4. Planetary reduction setup
-Sun gear as ‘driver’ and planets as ‘driven’
-Reduction ratio.
-Fixed position outer ring gear.

5. Planetary Design

6. Disadvantages of The Design
-Difficult to construct and assemble.
-Cannot be mounted.
-No room to account for motor and wall
-Expensive to build.

7. Gearbox Design - Spur Gear
Advantages:
• High Efficiencies (up to 98%)
• Simplistic; Easy to design &
manufacture --> Cheaper to make
• Well Researched; Long History
• Offers constant velocity ratio
• No slip and creep as opposed to
belt/chain.
Disadvantage:
• Cannot transfer power to non
parallel shafts
• Spur gears are expensive compared
to belts.
• Have limited transfer distance.
• Noisy at high speeds
• Gears experience a high amount of
stress.

8. Design Features – Housing
• No partitioning walls
• Plates have holes for
alignment
• Gearbox thickness is only
44mm, allows for
introduction of additional
gear sets
• Makes uses of rods to
improve rigidity (rod is
unlimited, rest is not)
• Whatever material left
over we can use to further
add to the housing.
(Adding plates)
• Fixed Axial – Reduce
induced friction on system

9. Design Features – Gear Mesh
• Spacers are used to separate
gears instead of using
partitioning walls. Thid
decreases the area of
rubbing between acrylic on
acrylic. Coefficient of friction
between acrylic and acrylic is
0.6-0.72
• More gearsets will decrease
overall gearbox efficiency,
with next evolution will try
and decrease number of
gearset from 6 to 5.
(http://www.matweb.com/search/DataSheet.aspx?MatG
UID=3cb08da2a0054447a3790015b7214d07)

10. Design Features – Gear & Pinion
• Gear has been optimized to
decrease its moment of inertia.
• Gear features two mechanism
for joining, pinning which will
offer shear resistance and
super glue which will provide
shear and axial load resistance
from coming apart.
• Advantage of this is that first
run can be done by simply
pinning them and then reusing
the 16T for next evolution.
• Pinning also serves as a method
of alignment (doesn’t really
matter with gears but does for .

11. Design Feature – Gear & Spool
• I intend to cut a 1mm thick piece
and use it to put along pulley
reduce friction more.
• Moment of inertia
Also note:
• Designed to max efficiency setting,
therefore any unaccounted or
unforeseen forces can be
overcome by increasing the power
from the supply. (Optimization
tells us difference now)
• Friend has a hobby shop – Can test
the efficiency of our gearbox.