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A Review onUse of rapid prototyping method for Manufacturing and examination of

Gear WheelsBy

M.Saras chandra 14MMF0011

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Index

1. Introduction2. Analysis of RP methods in terms of Application

for the manufacture of gear wheels3. Method for preparing geometrical data for RP

process4. Analysis of geometric accuracy for gear wheels5. Possibility of RP system application for gear

wheels Testing

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1.INTRODUCTION

• Rp Systems Make it possible to manufacture

prototypes of complex shapes including gear

wheels Prototypes.

• It is important for process of manufacturing gear

wheels of non-standard tooth profiles.

• For tooth contact analysis and Fatigue tests

Rapid Manufactured Non-standard Gear wheels

are used.

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2.ANALYSIS OF RP METHODS IN TERMS OF APPLICATION FOR THE MANUFACTURE OF GEAR WHEELS

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2.Analysis of RP methods in terms of Application for the manufacture of gear wheels

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2.1.JS method

• Layered jetting process known as JS method introduced by Jetting Systems.

• Application of layer of polymer from the print head and subsequent hardening of polymer layer by U.V. Light emitted by lamp integrated with print head.

• Models are print layer by layer.

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2.2.SLS METHOD

• SLS method consists of hardening the surface of powdered material by means of laser beam.

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2.3.SLA METHOD

• Oldest Method of Rapid Prototyping• By photo polymerisation of polymer resin

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2.4.FDM METHOD

• FDM is the process consists of use of material in filament form is heated , fused ,melted , extruded through nozzle and part fabricated layer by layer

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2.5.3D-PRINTING

• 3D-Printing consists in combining a powdered material in layers by means of binding agent applied by a printing head.

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COMPARISON OF RP PROCESS

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3.METHOD FOR PREPARING GEOMETRICAL DATA FOR RP PROCESS

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3.1.DATA FORMATS FOR RP PROCESS

• STL• IGES• STEP• HP/GL• CT DATA• SLC• CLI • RPI

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3.2 COMPARISON OF PROBLEMS IN STEP AND IGES

• In general Mapping errors between the facets will be occurred in IGES.

• In STEP accurate mapping is there but it is not a standard model for RP process. It is generally used for CNC-Programming.

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3.3.Stl file

Edge and vertex redundancy in Stl file

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STL Defects

1. Gaps , Cracks, Missing Facets: Due to Tessellation of surfaces with large

curvature can results in errors at intersections of surfaces, leaving gaps, holes along edges of part model.

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STL Defects

2. Degenerate Facets: These may be occur when all of the facets ,

edges are collinear even though all vertices are distinct. By stitching algorithms we can avoid shell punctures.

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STL Defects

3. Over lapping facets: Due to numerical round-off errors occurred

during tessellation. The vertices are represented as Floating integers in 3d-space instead of integers.

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STL Defects

4.Non-Manifold Conditions:1. Non-manifold edge2. Non-manifold Point3. Non-manifold faceDue to tessellation of fine features susceptible to round-

off errors

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3.4.Accuracy of Model mapping in STL format

complex gear teeth wheels profiles are complex in shape and while converting into Stl format there are so many mapping errors discussed before are occurred.

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3.5. DATA PROCESSING IN CAD SYSTEMS

• In mechanical desk top and Catia software consisting of Rapid proto typing modules have tessellation option to verify the model.

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3.6.DATA PROCESSING IN MAGIX R.P.SOFTWARE

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4.ANALYSIS OF GEOMETRIC ACCURACY FOR GEAR WHEELS

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4.Analysis of geometric accuracy for gear wheels

1. Measurement of test prototypes with CMM2. Measurement of test prototypes with ATMOS-

GOM system

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5. POSSIBILITY OF RP SYSTEM APPLICATION FOR GEAR WHEELS

TESTING

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5.Possibility of RP system application for gear wheels Testing

• Tooth Contact Analysis• Fatigue Tests for non- involute Gear wheels

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5.1.TOOTH CONTACT ANALYSIS

• Steps: 1. Making the stereo lithographic model of gears 2.Stand tests of contact area

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5.2.Fatigue testing of Non-involute Gears

• Finite element analysis will be done for the cad models

• Next for prototypes produced in SLA,FDM will be tested using Fatigue test machine.

• Minor difference is observed between the FEM results and gear wheel stand test fatigue machine

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The End