INTERFERENCE CHECKING BY Paul Thurber

When is a ½” not a ½” What do you do if it does not fit What do you do if it does not fit Who is responsible for the parts and pieces Who is responsible for the parts and pieces

History of Drafting Traditional Paper Drafting Traditional Paper Drafting Artwork Artwork Hard to update Hard to update Hard to Store Hard to Store

The CAD Revolution Computerized drafting Computerized drafting Faster Drafting Faster Drafting Easier Updating Easier Updating Easy To Store Easy To Store Instant Drawings Available Instant Drawings Available

Drafting Practices Drafter responsible for making parts fit Drafter responsible for making parts fit To insure proper fit tolerances were used To insure proper fit tolerances were used The more accurate the parts the closer the tolerances were required The more accurate the parts the closer the tolerances were required Locations of features were none standard Locations of features were none standard

Interference Was Engineers Responsibility Drafters made drawings Drafters made drawings Only did some drawings Only did some drawings Complete Assembly Complete Assembly Overall Performance Overall Performance

Tolerance Stacking a Problem An accumulation of many tolerances a problem An accumulation of many tolerances a problem With multiple drawings careful checking needed With multiple drawings careful checking needed

No Clear Standards The World Economy but no World Standards The World Economy but no World Standards How TO Convert from Measuring Systems How TO Convert from Measuring Systems Quality was Hard to Maintain Quality was Hard to Maintain

Change to Geometric Tolerances Drafting practices changed Drafting practices changed Geometric tolerances were developed Geometric tolerances were developed Consistent Drawing Features increases accuracy Consistent Drawing Features increases accuracy

Interference Checking Drafter was now responsible Drafter was now responsible New standards aided interference New standards aided interference Shop tolerances became standardized Shop tolerances became standardized

The New 3D CAD Can now draw in three diminsion Can now draw in three diminsion Growing ability to see how parts fit Growing ability to see how parts fit Multiple views for one part Multiple views for one part Solid modeling becomes reality Solid modeling becomes reality

Animation and CAD The next revolution was part animation The next revolution was part animation Exploding parts could be put together Exploding parts could be put together Overall planning and part manufacturing is part of the computer world Overall planning and part manufacturing is part of the computer world

CAD/CAM Computer Aid Design Becomes Computer aid Machining Computer Aid Design Becomes Computer aid Machining Drawings become machining programs Drawings become machining programs Drawings used to automate ordering Drawings used to automate ordering

Larger Role For CAD CAD becomes a Major engineering tool CAD becomes a Major engineering tool Automation of stresses and design Interference Automation of stresses and design Interference

From the Drawing Into Shop Floor Management Interference checking goes beyond parts Interference checking goes beyond parts Shop floor management begins at the design stage Shop floor management begins at the design stage The checking of tolerances is only a small part of the total capabilities The checking of tolerances is only a small part of the total capabilities

Assembly and Design Drafting parts with Design Becomes Art Work Drafting parts with Design Becomes Art Work Optimization of assembly through animation Optimization of assembly through animation Complete Assembly Drawings Complete Assembly Drawings

Assembly Is Automated The new CAD/CAM The new CAD/CAM Becomes point of assembly Becomes point of assembly Interference checking is automated Interference checking is automated

Boeing Aircraft Drafting becomes modular Drafting becomes modular Can check out designs without parts manufacturing Can check out designs without parts manufacturing Computer drafting becomes shop floor management Computer drafting becomes shop floor management

Tsinghua University Developed AOPDO Developed AOPDO Can make parts to optimize profits Can make parts to optimize profits Complete package for Manufacturing Complete package for Manufacturing

Interference Checking in Assembly The new programs aid in assembly The new programs aid in assembly Assembly functions can be automated Assembly functions can be automated Each Step is part of whole Each Step is part of whole

Interference Checking Is Quality The better the fit the higher the quality The better the fit the higher the quality Quality is designed into the part Quality is designed into the part Quality becomes a driving force Quality becomes a driving force

Quality is Automated Interference of Quality needs reduced Interference of Quality needs reduced Quality is Automated Quality is Automated

Winning Customers Faster modular designs Faster modular designs Customer needs addressed Customer needs addressed What is next What is next

Conclusions Old fashioned is hard to understand Old fashioned is hard to understand The next step is hard to understand The next step is hard to understand Can we truly automate manufatcuring Can we truly automate manufatcuring

References “An integrated Framework for the Assembly Oriented Product Design and Optimization” by Qiang Su Ph.D. School of Economics & Management Tsinghus University “An integrated Framework for the Assembly Oriented Product Design and Optimization” by Qiang Su Ph.D. School of Economics & Management Tsinghus University “Geo-Metrics II” by Lowell W. Foster “Geo-Metrics II” by Lowell W. Foster Boeing Aircraft Design Web Page Boeing Aircraft Design Web Page