scania step-nc machining demo

12008-03-12 mikael.hedlind@iip.kt

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Scania STEP-NC machining demoShowing benefits of using STEP-NC in the automotive industry

22008-03-12 mikael.hedlind@iip.kt

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Scania cylinderhead• Typical powertrain component• 450 000 produced part during year 2007• Machining features

– Planer face– Hole

• Machining operations– Planer mill– Drill– Ream

32008-03-12 mikael.hedlind@iip.kt

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Simplified part of Scania cylinderhead

42008-03-12 mikael.hedlind@iip.kt

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Activity model for STEP-NC demo

52008-03-12 mikael.hedlind@iip.kt

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Work instructions• Creation and maintenance of work instructions is time

consuming, even when having an more automated creation process.

• Information given in these work instructions is geometry faces with tolerances related to used cutting tool. This information can also be represented in a STEP-NC model.

62008-03-12 mikael.hedlind@iip.kt

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Work instructions as an view of STEP-NC data• Eliminating unnecessary information redundancy• Separation of representation and presentation• Fewer work instruction have to be created

72008-03-12 mikael.hedlind@iip.kt

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Machining demo video

82008-03-12 mikael.hedlind@iip.kt

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Tool compensator adviser• Difficult to cover every possible scenario• The adviser utility is not part of STEP-NC standard, it’s a

functionality utilizing the standard• Possible to implement for many more dimensional

toleranced cases• Discussion on how to compensate deviation

– Deflection, static and dynamic behavior– Axis motion delay– Individual cutting tool difference– Fixture placement error– Tool wear– …

92008-03-12 mikael.hedlind@iip.kt

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Contributors to this demo

102008-03-12 mikael.hedlind@iip.kt

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Live machining demo

112008-03-12 mikael.hedlind@iip.kt

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What we have done• Implementation of GD&T representation, not

presentation• Used recommended practices from CAx

Implementor Forum and www.wikistep.org• GD&T harmonization between Application

Protocols made our use of AP214e3 specification possible

• Use of both Geometric and Dimensional tolerances along with Surface condition requirement

• Together with STEP Tools Inc., developed presentation of relationship between tool and produced face with its tolerances

122008-03-12 mikael.hedlind@iip.kt

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How we have done• Reading ARM, mapping tables and AIM sections• Created instantiation structure with Graphical Instance to

represent tolerances for– Diameter Size Dimension (12 lines in file)– Linear Distance Dimension (16 lines in file)– Flatness Tolerance (6 lines in file)– Surface Texture (11 lines in file)

• Reuse of created part 21 blocks that appended in end of STEP geometry part 21 file

• Validated part 21 file with Express Engine• Developed a small Java application to automate append

process. Manual instantiation of STEP models is a good learning lesson but also very time consuming. Use of STEP SDK is preferred for effective work

132008-03-12 mikael.hedlind@iip.kt

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Express-G model for tolerance representation

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Java application• The purpose was to simplify writing tolerance information

during STEP-NC demo preparation• Not proposed solution

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Proposed GUI – Part Properties

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Then implemented GUI – Part Properties

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Proposed GUI – Tool view

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Then implemented GUI – Tool Properties

192008-03-12 mikael.hedlind@iip.kt

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Visualization format in STEP-manufacturing• ISO TC184 SC4, 54th Plenary meeting, Louisville USA

Presentations of candidate solutions 2008-03-03 – U3D – ECMA TC43– X3D – ISO/IEC JTC1/SC24– 3D-XML – Dassault Systemes– JT Open– MPEG-4 – ISO/IEC JTC1/SC29– COLLADA– Lattice 3D XVL

• An visualization solution should include process data in addition to product data

• Improves visual communication of manufacturing data

202008-03-12 mikael.hedlind@iip.kt

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Visualization format in STEP-manufacturing

• Scania cylinderhead AP214 p21 file size: 27660 kB• Scania cylinderhead Adobe 3D file size: 972 kB

(Adobe support U3D and others candidate STEP visualization solutions)

212008-03-12 mikael.hedlind@iip.kt

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Mikael HedlindM.Sc., Ph.D StudentKTH, Royal Institute of TechnologyComputer System for Design and Manufacturing

Machinist backgroundEmployed at Scania since 1998During 4 year worked with machining process optimizing and cutting tool evaluation at Scania.

Magnus LundgrenB.Sc., Ph.D StudentKTH, Royal Institute of TechnologyComputer System for Design and Manufacturing

Machinist backgroundHas worked as CNC-operator and manufacturing engineer for about 10 years before entering studies at KTH. Graduated for B.Sc. in 2001 and after that working with education at KTH in the area of manufacturing engineering.