[email protected] ENGR-22_Lec-10_Ortho_View-3.ppt 1 Bruce Mayer, PE Engineering 22 – Engineering Design Graphics Bruce Mayer, PE Licensed Electrical

[email protected] • ENGR-22_Lec-10_Ortho_View-3.ppt1

Bruce Mayer, PE Engineering 22 – Engineering Design Graphics

Bruce Mayer, PELicensed Electrical & Mechanical Engineer

[email protected]

Engineering 22

OrthroGrapOrthroGraphichic

View Dwgs-View Dwgs-33



Learning GoalsLearning 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



MultiView Steps SummarizedMultiView Steps Summarized

1. Pick Views

2. Block It

3. Grid It (Use Mitre Line)

4. Connect the Dots

5. Clean Up

6. Done



Cylinders w/ “Flats”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



Cylinders w/ Slant CutsCylinders w/ Slant Cuts When an Inclined

Plane Cuts a cylinder We can Arrange the Views to Show1. A Circle of Cylinder

Diameter

2. A EDGE VIEW (EV) of the cut Surface

3. An Ellipse – Usually in

profile

1

2

3



Cylinders w/ Slant Cuts Cylinders w/ Slant Cuts contcont

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

Known

AbritraryGrid-Pts

EV



Cylinder Drawing ConventionsCylinder Drawing Conventions

a) NARROW Prism Intersects Cylinder → Intersection in Front view is INSIGNIFICANT and Can be IGNORED

b) Prism is larger → Need to Construct the Front View Intersection



Cylinder Conventions Cylinder Conventions contcont

c) SMALL KeyWay Intersects Cylinder → Intersection in Front view is INSIGNIFICANT and Can be IGNORED

d) SMALL Hole Intersects Cylinder → Intersection in Front view is INSIGNIFICANT and Can be IGNORED



Plotting Elliptical CurvesPlotting 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

RndSurf

12

In the TopV Which In the TopV Which Surf is Round, and Which is Flat?Surf is Round, and Which is Flat?

• 1 Rnd or Flat?; 2 Rnd or Flat?1 Rnd or Flat?; 2 Rnd or Flat?



Plotting Elliptical Curves Plotting Elliptical Curves contcont

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


In the TopV Which In the TopV Which Surf is Round, and Which is Flat?Surf is Round, and Which is Flat?

• 1 Rnd or Flat?; 2 Rnd or Flat?1 Rnd or Flat?; 2 Rnd or Flat?

Slice Surf

RndSurf 1

2



Plotting Space CurvesPlotting 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




Comments on “Grid & Connect”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



HoleHoleCallOutsCallOuts

Drill Bit Pt Drawn at 60° Half-Angle

82° Counstink Drawn at 90°

CallOut ShortHand



Find ShortHand Symbols in ACADFind ShortHand Symbols in ACAD

Start MText In Formatting Tools

Pick SYMBOL

Click Other…

Activate GD&T Character Map



Fillets an

d R

ou

nd

sF

illets and

Ro

un

ds



Fillets, Rounds, SpotFacesFillets, Rounds, SpotFaces 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

Boss

Spotface



Surface InterSectionsSurface InterSections

Core Concept

The Intersection of any Combination of 2D or 3D Geometric Elements forms a LINE of INTERSECTION (LoI), or COMMON LINE



Surface Intersections contSurface 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



Curved vs Flat SurfacesCurved 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)



Cylinder vs Cylinder (1)Cylinder vs Cylinder (1) 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 (2)Cylinder vs Cylinder (2) 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 (3)Cylinder vs Cylinder (3)

1. 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

1




2. In P-Space use the Circumferential Divisions to Build a Series of Horizontal Cutting Planes (CPs)

3. From The CP-Circle intersections Extend into F-Spc the -Projectors to Establish the Small-Pipe Slice-Lines

2

3




4. Use P-Spc → H-Spc Depth Distance Xfer to Locate VERTICAL CPs that Correspond to the Horizontal CPs

5. Draw the Vertical CPs And Locate the Large-Pipe intersections (A, B, C)

4

5

Can also use Mitre-line to locate CPs in Top View




6. 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

6



Cylinder vs Cylinder (6)Cylinder vs Cylinder (6) In the Front View the

Slice-Line Grid-Intersections lie on the Common Line

7. Fair the Curve thru the Grid Intersections to Delineate the Line of Intersection • Use AutoCAD Spline

Command to draw a smooth, or “Faired” Curve

7



Cylinder vs Cone (1)Cylinder vs Cone (1) 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 (2)Cylinder vs Cone (2)

1. Construct True-Size View for CYLINDER X-Sec • The Circle in P-Space

in this Case

2. Divide the Circumference into Equal Parts to Locate Horizontal Cutting Plane Locations

• The Circle Divisions will be used to Make CP’s in Both the Side and FRONT Views

1

2




3. 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

3




4. 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

5. Draw the Slice-Line Concentric Circles

4

5




6. Use P-Spc → H-Spc Distance Xfer to Locate the Cylinder Slice-Lines in the H-View

7. 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

6

7Could Also Use

Mitre-Line to Xfer Depth

Dims to TopV




8. In H-Spc Connect the PP-Dots to form the Line of Intersection• Take Care to Ensure

Proper Visibility

9. From H-Spc PP’s Extend -Projectors into F-Spc to Locate PPs on the Cylinder Slice-Lines

10.Connect the F-Spc PPs to Build the LoI

8

9

10



All Done for TodayAll Done for Today

InterSectionsCan BeTOUGH

LoI



Bruce Mayer, PELicensed Electrical & Mechanical Engineer

[email protected]

Engr/Math/Physics 25

AppendiAppendixx

6972 23 xxxxf

Documents

[email protected] ENGR-22_Lec-10_Ortho_View-3.ppt 1 Bruce Mayer, PE Engineering 22 – Engineering Design Graphics Bruce Mayer, PE Licensed Electrical