CREATIVE JOURNEYKarl LankschJames McIvor

Conor CochraneInnes White

CONSTRAINTS & REQUIREMENTS

• Allowable gearbox materials are acrylic and glue.

• Must be cut from A4 sized sheet. • Must be securable to EN216 mounting

plate. • Set-up time should be minimal.• Able to drag 10kg weight up ramp. • String or chord must be used.

RESEARCHGEAR TYPES

PLANETARY GEARS

PROS• High gear ratios may be achieved

within a relatively compact size.• Longer gear life at similar loads• High efficiency – 95% per stage is

commonCONS

• Difficult to implement in acrylic sheet

• Requires more intricate parts- Higher risk of gearbox failure

• Generally loud when operating

HELICAL GEARS

PROS• Lower Kv value (dynamic factor)• Quiet when operating• Highly durable

CONS• Not practical to make via cutting

acrylic sheet• Not space efficient• thrust along the axis of the gear,

which needs to be accommodated by appropriate thrust bearings

SPUR GEARSPROS

• Easiest to make/assemble from acrylic sheet

• Mass can be lowered by removing non critical sections

• Easily layered for compact design• Can be paired to form reductions

CONS• Can be noisy at high operation

speeds• Gear teeth experience large

amounts of stress

PREFERRED OPTION

PREFERRED MATERIALSHeavy Gauge Fishing line

• Inexpensive• Built to sustain heavy loads

2 Part epoxy resin• Quick cure• Rated to tensile strength of

2400KPa

MIND MAP

Gear Box

Design

Types

HelicalBevel

Planetary

Spur

Performance

Power / Time /

Efficiency

MotorRampDimensio

nsAxial

Diameter

Teeth

Constraints

A4 sheet

Ramp

Material

LimitedProperties

Friction

Lubrication

Spur Gear

Designs

Gear Train / Dimensions

Chosen Concepts

SCAMPER

Reverse Reverse and repeat process until results are satisfactory

Eliminate

Eliminate any design existing design flaws

Put Put design to other groups for review

Modify Modify design, minimize waste, maximize gear efficiency

Adapt Adapt design components to accommodate the mount

Combine Combine concepts about gears for initial gear ratio and gearbox design

Substitute

Substitute different gears/gear ratios in theory

INITIAL GEARBOX IDEAThis gearbox has a gear ratio of 260:1It uses the gears and spacers in order to transmit the motors power via fixed shaftsThe gears involved are:1 – 16 toothed gear (input gear: does not need to be cut)1 – 40 toothed gear4 – 20 toothed gears4 – 64 toothed gears (1 of which will be our output gear)

Output gearSpacer

Input gear

FixedShaft Axials

Gear ratio calculations

G. R = (40/16) x (64/20)^4 : 1

G.R = (2.5 x 3.2^4) : 1 = 262 : 1

The gearbox uses one gear gear reduction of ratio 2.5:1

followed by 4 gear reductionsof ratio 3.2:1

INITIAL GEARBOX

IDEA