EAST MECHANICAL DEPARTMENT RAPID MANUFACTURING PROCESS RAPID MANUFACTURING PROCESS BHUBANESWAR,KHURDA

PRESENTED BY AMAN KUMAR PANDA MECHANICAL,GRP –ME1.(A)

THE COMMON MACHINE OPERATION STATIC MACHINE ELEMENT IN EXTRA ORDINARY SCIENCE

Common Machining Operations Kalpakjian

Parts of an “Engine” Lathe Kalpakjian

Typical “Engine” Lathe Watchmaker’s lathe Typical “Engine” Lathe www.ticktockpro.com www.blazingtech.net Turret Lathe Big “Engine” Lathe www.liberatorcrew.com www.bakerprovan.com.au

Really Big “Engine” Lathes www.practicalmachinist.com 60 feet c-c www.harrismachinetools.com

CNC Lathe: aka “Turning Center” (carriage is mounted toward back, “upside down”) www.machineryvalues.com

Machining Parameters DeGarmo

Machining: Turning Depth of Cut = DOC = (Dbefore – Dafter) / 2 Cutting Speed = Speed of metal moving towards cutting tip Usually called “Surface Feet per Minute”, SFPM, SFM Each cutting tool & workpiece material combo has a max SFM for decent tool wear. HSS & alum: 800 SFM HSS & 1020 steel: 110 SFM HSS & 1090 steel: 80 SFM HSS & hard 4140: 30 SFM TC & 1020 steel: 1000 SFM SFM = r*w = D * RPM * (π/12) ≈ D * RPM / 4 RPMmax = 4 * SFM / D (most useful machining formula) E.g., find RPM for turning 2” dia. 1020 steel: RPM ≈ 4*110/2 = 220 RPM may need to be less due to chatter! Most relations are similar for milling, but D=cutter dia. Kalpakjian

Cutting Forces DeGarmo

Orthoganal Model (2-force) DeGarmo

Orthoganal Model (2-force) DeGarmo

Chip formation: chip types DeGarmo Kalpakjian

Merchant’s Model (Simplified 2-force) DeGarmo

Chatter Vibrational resonance of entire machining system, especially workpiece-cutter. Causes poor surface finish, fast tool wear, noise Factors: stiffnesses of workpiece, cutter, machine cutting params: speed, feed, DOC cutter geometry: rake, clearances Solutions: Change the cutting params esp. speed Increase stiffnesses Kalpakjian

Heat rise in Cutting Kalpakjian

Temperature of Cutting Tip Kalpakjian/Vieregge

Temperature of Cutting Tip Kalpakjian / Chao & Trigger

Max Temperatures of Cutting Materials Kalpakjian

Machining Time of Cutting Materials Kalpakjian/Sandvik

Coated Carbide Cutting Inserts: The norm for production machining Layers are 2-10 microns thick: TiN: titanium nitride (low friction, gold appearance) TiCN: titanium carbonitride (wear resistance) Al2O3: Alumina (chemical stability, wear resistance) Tungsten Carbide substrate (~shock and wear resistance) www.greenleafcorporation.com www.moldmakingtechnology.com Kalpakjian/Kennametal

Cutter Shape and Geometry Kalpakjian

Machining Costs Kalpakjian

References