Docstoc

Estimation

Document Sample
Estimation Powered By Docstoc
					Design Drawings and Fab Specs




                                   Engineering Design
                                              GE121

                                  Design Drawings and
                                Fabrication Specifications
                                           Lecture 8D
                                        GE 121 Engineering Design--2011   1
                                 Design Drawings, Fabrication Spec‟s:
                                          Designing Isn‟t Building
Design Drawings and Fab Specs




                                Design Drawings and Fabrication
                                 Specifications are an essential part of
                                 reporting in many Design Projects
                                Allows someone you may not even know,
                                 to build your design
                                Must pay attention to the kind of drawings,
                                 and different standards associated with
                                 Final Design Drawings

                                               GE 121 Engineering Design--2011   2
                                             Design Drawings
                                Can include:
Design Drawings and Fab Specs




                                  Freehand
                                  CADD Models
                                  Sketches
                                Often include
                                 “marginalia”
                                  Notes for the
                                   user of the
                                   drawing
                                                              Fig. 8.1 p191

                                                   GE 121 Engineering Design--2011   3
                                          Design Drawings                      (continued)
                                Layout Drawings
Design Drawings and Fab Specs



                                  Working drawings that show the major parts or
                                   components, and their relationships
                                      Usually to scale
                                      Do not show tolerances
                                      Subject to change as design process continues




                                                                                             Fig. 8.2
                                                                                             p192

                                                     GE 121 Engineering Design--2011                    4
                                          Design Drawings                       (continued)
Design Drawings and Fab Specs


                                Detail Drawings
                                  Show Individual parts or
                                   components and their
                                   relationship
                                      Show tolerances
                                      Indicate materials
                                      Any special processing
                                      Conform with existing
                                       Drawing standards
                                      Changed only with a
                                       „Change Order‟



                                               Fig. 8.3 p193


                                                      GE 121 Engineering Design--2011         5
                                          Design Drawings                    (continued)
                                Assembly
Design Drawings and Fab Specs



                                 Drawings
                                  Show how the
                                   individual parts or
                                   components fit
                                   together
                                  Exploded view
                                   commonly used
                                  Components
                                   shown by part
                                   number, or on
                                   entry in a Bill of
                                   Materials
                                                                                      Fig. 8.4 p194
                                                   GE 121 Engineering Design--2011                    6
                                        Design Drawings                   (continued)
Design Drawings and Fab Specs



                                Bill of Materials
                                  List of parts required to create the artifact
                                Standards for Drawings
                                  Various standards, depending on discipline
                                  ANSI is a clearing house for various drawing
                                   standards for various disciplines




                                                GE 121 Engineering Design--2011         7
                                          Fabrication Specifications
Design Drawings and Fab Specs



                                Set of plans that form the basis on which the
                                 designed artifact will be built
                                Should be:
                                   Unambiguous (role and place or each part
                                    unmistakable)
                                   Complete (comprehensive)
                                   Transparent (readily understood)
                                Allows someone totally unconnected to the design
                                 to be able to build it
                                Our focus in this class is conceptual design – we
                                 will not discuss fabrication specifications in detail
                                                   GE 121 Engineering Design--2011   8
                                    Fabrication Specifications (continued)
                                Many of the components/parts may be purchased
Design Drawings and Fab Specs



                                 from vendors, requiring a great deal of detailed,
                                 disciplinary knowledge
                                Some requirements of fab spec‟s can be:
                                  Physical dimensions
                                  Kinds of materials
                                  Unusual assembly conditions
                                  Operating parameters (artifact‟s response/behaviour)
                                  Maintenance / Lifecycle requirements
                                  Reliability requirements
                                  Packaging requirements
                                  Shipping requirements
                                  External markings (usage/warning labels)
                                  Unusual or special needs
                                                  GE 121 Engineering Design--2011         9
                                            Philosophical Notes
                                     Specifications / Drawings / Pictures
Design Drawings and Fab Specs



                                Type of drawings and level of detail varies
                                 by discipline
                                  Schematic often good in electronics, but not in
                                   mechanical
                                  Types of drawings have evolved separately in
                                   various fields
                                Visual representation is often much more
                                 easily interpreted than written
                                Photographs may begin to become more
                                 important (Google Earth  GIS Systems)
                                                GE 121 Engineering Design--2011   10