Engineering Design Graphics Test 2 : Chapter 4 and 6

Sold Models

They are required to have a manifold model

CSG( constructive solid geometry)

uses solid primitives that are related to boolean operations

Boolean Operations

union, difference, and intersection

Union

Joining two parts together

Difference

Subtracting one solid from another

Intersection

Results in a solid that form by theoverlapping of two solids

Solid Modeling 3D Operations

Extrude, Revolve, Sweep, Loft

Model Planning

Design Intent, modifications by changing size location and number of features

Feature Ordering

affects the final geometry of the part as well as efficiency

ANSI(American National Standards Institute)

Dimensioning Standards, most current and commonly used ASME Y14.5

Basic Dimension

Theoretical exact size (Has a box around it)

Reference Dimension

For information ONLY(has Parentheses around it)

Limits of Part Size

Maximum Material Condition(MMC), Least Material Condition(LMC)

Coordinate Dimensioning

Datumn, Tabular

Current standard for dimensioning based off of ASME Y14.5

Unidirectional

Not to Scale

displayed with an underline

Counterbore or spot face symbol

open top square

Countersink Symbol

arrow pointing down

Diameter Symbol

Circle with line through it

Square symbol

square

depth symbol

horizontal line with an arrow pointing down attached

Tolerance

are used to control the variation onall manufacturing parts

Interchangeability

The greatest impact of tolerance on parts is that the parts can be interchanged (Bolt and Nut)

Tolerances can be applied in several ways

Direct limits
Geometric Tolerance
Notes referring to specific conditions
A general notes in title block

Nominal Size

General size in fraction ½"

Basic Size

Theoretical size as a starting point

Actual Size

Measure size of finished parts

Allowance

the minimum clearance or maximum interference between parts

Piece Tolerance

the difference between theupper and lower limits of a single part

System Tolerance

the sum of all piece tolerances

Fit Types

The degree of tightness between the mating parts is called Fit
Clearance Fit
Interference Fit
Transition Fit

Functional Dimensioning

practice thatthe parts that come in contact will getdimensioned and tolerance first

Stack-Up Tolerance

Additive Rule fortolerance. This happens when we dimension mating parts from different directions

When are angled extension lines used?

angling of extension lines is permissible when space is limited

When should extension lines be broken?

When extension lines cross or are close to arrow heads, they should be broken for the arrowhead

How is a reference dimension identified?

It is enclosed in parentheses

How can you tell if a dimension is out of scale (without measuring the drawing)

When the dimensioning is written with an underline it means "Not to Scale"

Describe the difference between the MMC conditions of a shaft and the MMC condition of a hole

Hole MMC:MMC condition is when the hole has its smallest permissible diameter. This is because the hole at its smallest diameter has the most material around it.
Shaft MMC:he MMC condition is when the shaft has its largest permissible diameter. This is because the shaft at its maximum diameter has the most material.

How does a shaft depart from MMC? How does a hole depart from MMC?

Shaft MMC:A shaft departs from MMC when it is manufactured with a smaller diameter than its maximum permissible size
Hole MMC:A hole departs from MMC when it is manufactured with a larger diameter than its minimum permissible size.

Limit Dimensioning

the upper and lower limits of the dimension are specified directly, giving the maximum allowable size and the minimum allowable size

Plus and Minus Dimensioning

In plus and minus dimensioning, a nominal (target) dimension is specified, followed by an allowable tolerance range

What is the difference between limit dimensioning and plus and minus dimensioning?

Both methods serve the purpose of defining tolerances, but limit dimensioning directly specifies the range, while plus and minus dimensioning provides a nominal size with a tolerance range around it.

Compare the thickness of dimension lines to object lines

Object Lines: Thicker lines used to define the part's shape and boundaries.
Dimension Lines: Thinner lines used for measurement annotations, ensuring that the part's shape (outlined by object lines) remains the primary focus.