Bruce Mayer, PE Licensed Electrical & Mechanical Engineer BMayer@ChabotCollege

1. Engineering 22 OrthroGraphicView Dwgs-3 Bruce Mayer, PE Licensed Electrical & Mechanical EngineerBMayer@ChabotCollege.edu

2. Learning Goals • Construct MultiView Orthographic Projection Drawings for • Straight Cuts into Curved Surfaces • Curved Cuts into Straight/Flat Surfaces • Curved Surfaces in 3D Space Using the Mitre Line • Special Holes, Fillets & Rounds • Ortho Projection for solid-form intersections

3. MultiView Steps Summarized • Pick Views • Block It • Grid It (Use Mitre Line) • Connect the Dots • Clean Up • Done

4. Cylinders w/ “Flats” • Many Times Shafts or Pipe will have Cuts Made Parallel to the Axis • This Produces a “Flat” on the Cylindrical Object • Procedure • Drawn Known Lines • Grid/Mitre & Connect Dots Known Known

5. Cylinders w/ Slant Cuts • When an Inclined Plane Cuts a cylinder We can Arrange the Views to Show • A Circle of Cylinder Diameter • A EDGE VIEW (EV) of the cut Surface • An Ellipse • Usually in profile 1 2 3

6. Cylinders w/ Slant Cuts cont • Same Procedure as with All Other Ortho Projections Except the Grid Pts are ARBITRARY on the Known curved Surfaces • Pick Evenly Spaced Pts on CIRCLE • Grid DOWN and to MITRE • Connect Dots Known AbritraryGrid-Pts EV Known

7. Cylinder Drawing Conventions • NARROW Prism Intersects Cylinder → Intersection in Front view is INSIGNIFICANT and Can be IGNORED • Prism is larger → Need to Construct the Front View Intersection

8. Cylinder Conventions cont • SMALL KeyWay Intersects Cylinder → Intersection in Front view is INSIGNIFICANT and Can be IGNORED • SMALL Hole Intersects Cylinder → Intersection in Front view is INSIGNIFICANT and Can be IGNORED

9. Plotting Elliptical Curves • Flat Slice Taken Off a ¼-Round Cyl • Front and RS Views Known • Pick in RS-View the Arbitrary, But Evenly Spaced, Grid Pts 1,2,3 • Grid & Mitre Top View • Connect The Dots Slice Surf 2 1 RndSurf • In the TopV Which Surf is Round, and Which is Flat? • 1 Rnd or Flat?; 2 Rnd or Flat?

10. Plotting Elliptical Curves cont • SQ-Bar is “Scooped Out” and “Sliced Off” at Rt-End • Front and RS Views Known • Pick in Front-View the Arbitrary, But Evenly Spaced, Grid Pts 1,2,3 • Grid & Mitre Top View • Connect The Dots Slice Surf RndSurf 1 2 • In the TopV Which Surf is Round, and Which is Flat? • 1 Rnd or Flat?; 2 Rnd or Flat?

11. Plotting Space Curves • Plot Space (a.k.a. Irregular 3D) Curves with the “Grid & Connect” Method • In this Case • Top and RS Views Known • Pick in RS-View the Arbitrary, But Evenly Spaced, Grid Pts 1-6 • Grid & Mitre Front View • Connect The Dots

12. Comments on “Grid & Connect” • Draw KNOWN Views FIRST • Pick CURVED View for Picking the Arbitrary Grid Points • Even Spacing is Nice, but Not Necessary • Mitre Line will accommodate any spacing • MORE Pts → MORE Accuracy

13. HoleCallOuts • Drill Bit Pt Drawn at 60° Half-Angle • 82° Counstink Drawn at 90° • CallOut ShortHand

14. Start MText In Formatting Tools Pick SYMBOL Find ShortHand Symbols in ACAD • Activate GD&T Character Map • Click Other…

15. Fillets and Rounds

16. Fillet → Radiused INTERNAL Corner Round → Radiused EXTERNAL Corner Boss → Raised, Machined-Flat Cylindrical surface SpotFace → provides a seat or flat surface at the entrance and surrounding area of a hole Fillets, Rounds, SpotFaces Spotface Boss

17. Surface InterSections • Core Concept The Intersection of any Combination of 2D or 3D Geometric Elements forms a LINE of INTERSECTION (LoI), or COMMON LINE

18. Surface Intersections cont • Construct the Common Line between 3D shapes Using The “GRID & CONNECT” Technique • Locates the PIERCING POINTS (PP) • Connect the PP Dots to Establish Common Lines on the Shape SURFACES

19. Curved vs Flat Surfaces • In General, Curved Surface InterSections Generate NONLinear Common Lines • Often in Very Irregular Shapes • For Curved Surfaces Use a Well-Placed GRID • The Grid INTERSECTIONS Locate the PIERCING POINTS • Connect the PP Dots with a “Faired” Curve (use AutoCAD SPLINE curve)

20. Consider The Industrially Important (think Pipes) Situation Where Two Cylinders interSect with their CenterLines forming a RIGHT Angle Find the Line of Intersection (LoI) Cylinder vs Cylinder (1)

21. Solution Plan Obtain Small-Pipe Cross-Section in a True-Size Circular View Divide the Circle into Equally Sized Arcs; e.g., 30° Apart Use the Arc-Ends as the Locations for a Series of Horizontal GridLines Locate the Pts in other view to complete Grid Cylinder vs Cylinder (2)

22. In Profile Reveal the Circular X-Sec for the Small Pipe. Divide the Pipe Circumference into Closely Spaced Equal Parts In this Case Use 30° Segments Increasing the No. of Divisions increase the Accuracy of the LoI Cylinder vs Cylinder (3) 1

23. In P-Space use the Circumferential Divisions to Build a Series of Horizontal Cutting Planes (CPs) From The CP-Circle intersections Extend into F-Spc the -Projectors to Establish the Small-Pipe Slice-Lines Cylinder vs Cylinder (4) 2 3

24. Use P-Spc → H-Spc Depth Distance Xfer to Locate VERTICAL CPs that Correspond to the Horizontal CPs Draw the Vertical CPs And Locate the Large-Pipe intersections (A, B, C) Cylinder vs Cylinder (5) 5 4 • Can also use Mitre-line to locate CPs in Top View

25. From The CP-Circle intersections Extend into F-Spc the -Projectors to Establish the Large-Pipe Slice-Lines The Front View is Now Fully GRIDDED with Rectilinear Slice Lines Cylinder vs Cylinder (5) 6

26. In the Front View the Slice-Line Grid-Intersections lie on the Common Line Fair the Curve thru the Grid Intersections to Delineate the Line of Intersection Use AutoCAD Spline Command to draw a smooth, or “Faired” Curve Cylinder vs Cylinder (6) 7

27. Consider the Right Cone Intersected by a Cylinder where the Cone and Cylinder Axes form a 90° Angle Find the Surface Intersection Solution Plan Use Cutting Planes From Circular End-View to Find Piercing Points Cylinder vs Cone (1)

28. Construct True-Size View for CYLINDER X-Sec The Circle in P-Space in this Case Divide the Circumference into Equal Parts to Locate Horizontal Cutting Plane Locations Cylinder vs Cone (2) 1 2 • The Circle Divisions will be used to Make CP’s in Both the Side and FRONT Views

29. Use the Circle Divisions to Construct Horizontal CPs in the Adjacent P & F views Note that in The F-View the CPs are CoIncident with the Slice Lines The F-View Horizontal CPs result in Cone Slice-Lines that Appear in the H-View as CONCENTRIC Circles Centered on the Vertex Cylinder vs Cone (3) 3

30. In the F-View Extend into H-Spc -Projectors from the Cone-Edge and CP intersection to a diameter of the cone Base to Establish the Radius of the Slice-line Circles Draw the Slice-Line Concentric Circles Cylinder vs Cone (4) 5 4

31. Use P-Spc → H-Spc Distance Xfer to Locate the Cylinder Slice-Lines in the H-View Draw in H-Spc The Cylinder Slice-Lines The H-View is now Fully “Gridded” by Slice-Lines The intersection of the Cone Slice-Circles and the Cylinder Slice-Lines Locates the Piercing Points for the H-View Common Line Cylinder vs Cone (5) Could Also Use Mitre-Line to Xfer Depth Dims to TopV 7 6

32. In H-Spc Connect the PP-Dots to form the Line of Intersection Take Care to Ensure Proper Visibility From H-Spc PP’s Extend -Projectors into F-Spc to Locate PPs on the Cylinder Slice-Lines Connect the F-Spc PPs to Build the LoI Cylinder vs Cone (6) 8 9 10

33. All Done for Today InterSectionsCan BeTOUGH LoI

34. Engr/Math/Physics 25 Appendix  Time For Live Demo Bruce Mayer, PE Licensed Electrical & Mechanical EngineerBMayer@ChabotCollege.edu