Product Design & DevelopmentRedesign of a Reebok Edge Series Cross Trainer Foot Plate

Linkage

Student Name Tony PonsonbyStudent Number 02968984Unit Name Product Design And

DevelopmentUnit Code 64ET7004 1112 9Assignment Code 2CWK30

Stage 1 CompletionCompletion

Initial Material Selection

Initial FEA

CES Material Selection

Aesthetics Of Design User

Interface

Further FEA

Loading Types

Final Design

Environment Impact

Drawings & Renders

Motion Simulation

Design Selection

3D Refinement

British Standards

Which direction now?

Proposed Design

Initial FEAAcetal• 120kg load• Young's modulus 3.54GPa• Tensile strength 73.3MPa• Yield strength 59.3MPa

Possible New Linkage MaterialsPC – polycarbonateABS - acrylonitrile butadiene styreneHDPE - high density polyethylenePEEK – polyetheretherketoneAcetal – POM

Initial FEAAcetal120kg load Young's modulus 3.54GPaUTS 73.3MPaYield strength 59.3MPa ResultsMax Principle stress - 55.53MPaVon-Mises stress – 72.82MPaDeflection - 7.47mmConclusion - Stronger more rigid material required

Data from CES software

Material SelectionProperties of Plastic

Material SelectionCriteria• High Young's Modulus >14GPA• High Tensile strength >50MPA• Low cost <£8/kg• Opaque • Good Processability• Recyclable?

Material Selection

Material SelectionSPS Syndiotactic Polystyrene 40% Glass FiberDensity 1360-1380 kg/m^3Price 2.58-3.86 GBP/kgTradenamesEdgetek; Schulatec; Questra; XarecComposition overview

Polystyrene homopolymer (CH2CH(C6H5))n of regular syndiotactic stereochemistry with impact modification. With reinforcing filler.

Thermoplastic : semi-crystallineMechanical propertiesYoung's modulus 10-15.2 GPaYield strength 110-147 MPaTensile strength 96.5-140MPaCompressive strength 92.6-134MPaFlexural strength 161-231 MPaElongation 0.7-2.04 % strainMelting point 240-260 °C

Optical propertiesTransparency Opaque

Recycle False

Downcycle True

Combust for energy recovery True

Landfill True

Typical uses

Specialized components for automotive, electrical, electronic, and consumer/industrial products, such as connectors and microwave oven parts

Data from CES

Design to Standards

BS EN 957 Stationary training equipment —Part 1: 2005 General safety requirements andtest methodsPart 9: 2003 Elliptical trainers, additionalspecific safety requirements and testMethodsBSEN 15312:2007 Free access multi-sports equipment

Design to StandardsFOOT PLATE SIZE

BS EN 957 Part 9: 2003 clause 5.5 requires that ‘ the foot platforms have a non slip surface of at least 300mm x 100mm and a friction actor of more than 0.5 when tested to ISO5904’

MOTION

Design to StandardsFOOT PLATE GRIP DESIGN

Design to StandardsBS EN 957 Part 9: 2003 clause 5.5 requires that ‘The footplatform shall have a

guard with at least 30mm height along the inside edge and the front edge’

Design to StandardsTrainer Classification as BS EN 957-1:2005

Load testing to BS EN 957-9:2003

Design to StandardsLoad testing to BS EN 957-9:2003

Design to StandardsLoad testing to BS EN 957-9:2003

Design to StandardsClassification H - 250KG Loading

Design to StandardsClassification H - 250KG Loading

Design to StandardsClassification S - 400KG Loading

Design to StandardsClassification S - 100KG Loading

ConclusionSPS is suitable for H classification trainers

SPS not suitable for S classification trainers

The design could be used for S classification using a material with a Young’s Modulus >24GPa Yield Strength > 150MPa

PP66 with 30% carbon fiber is suitable for H classification trainers

Shape Optimization

CURVATURE OF SHAPE

INITIALPROPOSAL

REFINEDDESIGN

Exploded View

Eco Audit Report

Product Name

Reebok Cross Trainer Linkage

Product Life (years)

3

Energy and CO2 Footprint Summary:

Energy Details...

CO2 Details...

Phase Energy (MJ) Energy (%) CO2 (kg) CO2 (%) Material 176 81.2 12.2 80.0 Manufacture 36.8 17.0 2.76 18.2 Transport 3.59 1.7 0.255 1.7 Use 0 0.0 0 0.0 Disposal 0.321 0.1 0.0225 0.1 Total (for first life) 216 100 15.2 100 End of life potential -171 -11.8

Environmental ReportDowncycle at EOL

Criteria– Component weight 1.6kg– Manufactured in China &

transported to Manchester

– Re-engineered at end of life

– 15.2kg CO2 required for a 1.6kg?

– Combustion only returns 10MJ but adds 2.6kg CO2

emissions

Tooling

Design Benefits

Original Design New DesignNumber of parts 80 16Manufacturer assembled components 24 6User assembled components 56 10Weight 6.03kg 3.18kgCross trainer Classification H H&SRecycle

Steel Yes -ABS Downcycle/Combust -SPS - Downcycle/Combust

Future Work• Rapid prototype• Physical testing as designated by BS EN957-1;2005

– Load test as per as per clause 5.3.1 in accordance with clause 6.4

– Fatigue / Cyclic loading as per clause 5.7 in accordance with clause 6.7

– Friction factor test as per clause 5.5 in accordance with clause ISO 5904

Redesigned using SPS Syndiotactic Polystyrene 40% Glass FiberReduces user-assembled components by 64Reduces weight by 2.85kgDesigned for class H (home use) Elliptical Trainers as per BS EN 957–1:2005Redesign of a Reebok Edge Series

Elliptical Trainer Foot Plate LinkageProduct Design & DevelopmentTony Ponsonby 14/12/2011