Eng dwg 1011-1_wk2_gc_&_2d

Week 2Week 2MME 1211, Sections 5 & MME 1211, Sections 5 &

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Geometrical constructionsGeometrical constructions

Locating points anddrawing lines

Construction of angles

Types of polygons

Parts of a circle

Solid types

Bisection of lines and angles

Bisection of lines

Dividing a line into equal and proportional

parts

Construction of triangles

Construction of pentagon and hexagon

Drawing of a hexagon and octagon

Drawing of circle

Tangency

Drawing tangents to circles

Drawing arc tangents

Drawing arc tangents

Drawing arc tangents

Drawing arc tangents

Drawing arc tangents

Drawing an ogee curve

Conic sections

Construction of an ellipse

Construction of an ellipse

Construction of an ellipse

Construction of an ellipse

Drawing tangents to an ellipse

Drawing of a parabola

Drawing of a hyperbola

Drawing helix and involute

Extend Figure Trim Figure 2D Fillet 2D Chamfer Mirror Move Rotate Repeat Template Shape Offset Constraints

CAD-Editing and Modifying Tools

Extend Figure

Extend is used to extend the sketched entity to intersect the next available entity.

The sketched entity is extended up to its intersection with another sketched entity or a model edge.

Trim Figure To remove unwanted intersect

portion of a sketched element

2D Fillet To create a corner between 2

intersection with a given radius

Sketched entities before and after filleting

Sketched entities before and after filleting

2D Chamfer

To create a chamfer of a figure with a given distance. Default 45 degree.

Mirror

Creating a reflection copy of the figure about an axis line

Move is used to move the selected entities from

its base location to a desired location.

Start point of translation

End point of translation

Rotate

is used to spin the selected entities from its base location to a desired location.

Centre point of rotation

RepeatWhile sketching the base feature of a model, sometimes you may need to place the sketched entities in a particular arrangement such as along linear edges or around a circle.

Base feature with slots created about linear edges

Base feature with slots created around a circle

Repeat: Linear

original

horizontal linear path

vertical linear path

Repeat: Circular

original

centre of rotation

Practice 1-1In this practice, you will draw the sketch shown in Figure B on one side and then mirror it on the other side. The solid model is given only for your reference. Use Dimension tool to dimension the sketch accordingly.

Figure A Model for Practice 1-1 Figure B Sketch of Practice 1-1

Editing and Modifying Tools

Template Shape Offset

Shape

Creating a template or pattern of shape shown above:

1. Round 2. Square3. Obround4. Rectangle

1 2 3 4 5 6 7

Shape-Pattern Type

Offset Offset an element(s) at a specified

distance.

Offsetting a chain of entities Offsetting a single entity

Constraints

1. Fix2. Vertical3. Horizontal4. Intersection5. Symmetric6. Coradial7. Concentric

8. Colinear9. Coincident10. Midline11. Equal12. Tangent13. Perpendicular14. Parallel

1 2 3 4 5 6 7 8 9 10 11 12 13 14

Constraint are used to add relationship between sketched entities to capture the design intent. Below are constraints, some of which are applied automatically.

Horizontal constraint : forces one or more selected lines to become horizontal

Vertical constraint : forces one or more selected lines to become vertical

Fix constraint : forces the selected entity to be fixed at the specified position.

Constraint Term Definitions

Intersection constraint : forces the selected point to move at the intersection of two selected lines

Intersection between 2 lines

Original Position

Circle new position when applied intersection constraint

Symmetric constraint : forces two selected lines, arcs, points and ellipses to remain equidistant from a centreline or reference line. This constraint also forces the entities to have the same size and orientation.

Constraint Definition cont...

Coradial constraint : forces the selected arcs or circles to share the same radius and the same centre points.

Concentric constraint : forces the selected arcs and circles to share the same centre points with other arc, circle, point, vertex or circular edge.

Colinear constraint : forces the selected lines to lie on the same infinite line

Constraint Definition cont...

Midline constraint : forces the selected point to move to the midpoint of a selected line.

Equal constraint : forces the selected lines to have equal length and the selected arcs, circles to have equal radii.

Coincident constraint : forces the selected point to be coinceident with the selected line, arc, circle, or ellipse.

Constraint Definition cont...

Tangent constraint : forces the selected arc, circle, spline or ellipse to become tangent to the other arc, circle, spline, ellipse, line or edge.

Perpendicular constraint : forces the selected lines to become perpendicular to each other.

Applying the Tangent relation to a line and a circle

Entities before and after applying Perpendicular relation

Constraint Definition cont...

Entities before and after applying Parallel relation

Parallel constraint : forces the selected lines to become parallel to each other.

Constraint Definition cont...

Draw the sketch shown below. Use Tangent Constraint to connect the line to the outer arc and Trim the access entities.

Practice 2-1

Class Assignment c1w2Draw the hand-wheel shown below using the editing and modifying tools that you have learned. Unit = mm

Draw the figure shown below using the editing and modifying tools that you have learned. Unit = mm

Class Assignment c2w2

Draw the Figure shown below. Dimensions are in inches

Class Assignment c3w2