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Engineering 22. Working Drawings-1. Bruce Mayer, PE Registered Electrical & Mechanical Engineer BMayer@ChabotCollege.edu. Skill-Development Goals. Construct “Working Drawings” from the Two Primary Components ASSEMBLY Drawing Parts List (a.k.a. Bill of Material, or BoM)
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Engineering 22 WorkingDrawings-1 Bruce Mayer, PE Registered Electrical & Mechanical EngineerBMayer@ChabotCollege.edu
Skill-Development Goals • Construct “Working Drawings” from the Two Primary Components • ASSEMBLY Drawing • Parts List (a.k.a. Bill of Material, or BoM) • Use AutoCAD to Insert and Scale Up/Down a Standard Title Block to Fit the Assembly Drawing • Place BoMs on the AutoCAD Title Block
Working Drawings • Defined → A final set of production drawings providing all of the necessary details and specifications needed to Fabricate and/or assemble a product or system. • Three Main Parts • Detail (Fabrication) Drawings • Assembly drawings • Parts lists • Reference Dwgs • Layouts • Fit & Function • Schematics • Electrical & Plumbing • Concept Drawings • 3D, Flow Charts, etc.
Detail Drawings • Show all necessary dimensioned views needed to make the part. • Indicate material and tolerances. • Indicate any finish treatments (plating, etc.) and requirements for surface-finish roughness. • Detail drawings are not necessary for purchased parts, only for parts that will be manufactured to the Engineer’s design. • It is often preferred to show just one part per sheet so the same part drawing can be included in multiple assemblies without confusion.
Fabrication Drawing TWO Parts on this Sheet Poor form
Legal Interpretations • A part manufactured to within specifications and per the Drawing MUST Be Purchased • Parts can be rejected for not meeting any ONE Specification of a Drawing-Feature • Some Gray Areas • Unreleased Drawings & Sketches • Usually the ORIGINATOR Bears The Risk • Typically Only Done in “Short-Run” Situations • Originator vs. Receiver Interpretation • Drawings and Specs Need to be PRECISE
Assembly Drawings • Can be exploded-isometric, sections, single views, exterior views, or assembled isometric drawings. • Not usually dimensioned unless there are dimensions that are critical to maintain during assembly. • Hidden lines not usually needed.
Parts Lists (Bill of Materials) • Parts list (a.k.a. “BoM”) on assembly drawings or combined assembly and detail drawings indicates part name, item number, material, and quantity required. • Parts List May be on A Separate Document • Reference in NOTES Section of the Dwg • Often a company stock number is also included • Part ID on Dwg • Balltags on drawing indicate which part is being called out (next slide) • Part No. may be Placed Directly on Drawing
Ball-Tag BoM Assy Dwg BallTag Ref. toParts List
Hatch Patterns Indicate Parts • Different hatch patterns indicate which part is which in the assembly section. • The material for the part can be identified by different hatch patterns. • The hatch patterns run at different angles on different parts in the assembly
Thin Parts Filled In Black • Thin parts like the gasket shown here are too small to hatch. • Parts like these are filled in solidly with black.
Cross-Section Layout • Hatch Direction and/or Color Clearly Distinguishes Different parts
Reference Drawings • Parts/Systems are Typically NOT CONSTRUCTED to REFERENCE Drawings • Ref Drawings are Created to Aid in the Understanding of • Fabrication • Assembly • Trouble-Shooting • Maintenance • Product Use
Ref Drawings - Types • Layout Drawings • Used for Fit and Function Understanding • Schematics → Component Interconnect • Used to Aid in Understanding of System Function • Classic Types • Plumbing • Electrical • Many Other Types Exist
Combined Assy & Schematic Typically used in conjunction with a LayOut Dwg
All Done for ToDay Yet AnotherWorkingDwg
Engr/Math/Physics 25 Appendix Time For Live Demo Bruce Mayer, PE Licensed Electrical & Mechanical EngineerBMayer@ChabotCollege.edu