Exam 2

Question 1

When an instance of a part is brought into an assembly how many degrees of freedom does it have before any constraints are applied? #11

Answer 1

6

Question 2

11

describe associativity? #11

Answer 2

it is like a cloud system, where if you change a feature on one part all instances will also change

Question 3

11

What is the difference between components and instances?

Answer 3

Components are the parts that make up a system, while instances are copies of the components

Question 4

11

describe a subassembly

Answer 4

a group of components that serve a single purpose

Question 5

11

what is the purpose of assembly constraints and what are they called in solidworks?

Answer 5

assembly constraints help set the dimensional relationship between instances, they are called mates e

Question 6

11

In assembly modeling, the copies of a component within the system are called

Answer 6

instances

Question 7

11

in assembly modeling, you can apply ____ btw two 3-D instances so they maintain their geometric relationships within the assembly

Answer 7

assembly constraints/ mates

Question 8

11

An assembly that is fully constrained is ______
a. dimensional b. concentric c. rigid d. movable

Answer 8

rigid

Question 9

What is the diff between interferences and clearances when trying to mate 2 parts in a assembly? #11

Answer 9

Clearance is the minimum distance allowed between parts, like when the shaft of a screw is a lot smaller than the hole. Interferences is the amount of overlap btw 2 parts when a screw is much larger than the hole

Question 10

12

Why is MBD (model based definition) so important?

Answer 10

it allows us to annotate and define 3D models on CAD instead of having to present all the information with 2D drawings

Question 11

12

describe the purpose of Multiview presentation

Answer 11

it allows us to view all views of a part on the same plane

Question 12

12

How are viewing planes related to orthogonal projection?

Answer 12

viewing planes are transparent planes that are fixed to your line of sight, while orthogonal projection is the projection of a 3d model on the viewing plane where a face is parallel to the plane

Question 13

12

What are object lines?

Answer 13

They are the visible and dark lines that represent edges

Question 14

12

What are hidden edges?

Answer 14

They are the dotted lines that represent the obscure and blocked off features

Question 15

12

What are centerlines?

Answer 15

They mark the center of a circular hole with 4 lines

Question 16

12

What is the difference between first angle and third angle projection?

Answer 16

Third angle uses 3 views with the front view being the rear view, while first angle uses 6 different views

Question 17

12

What is a pictorial view? and the 3 types?

Answer 17

It is a view that allows you to see 3d objects. The 3 types include isometric, perspective, and oblique.

Question 18

What is the difference between isometric, diametric, and trimetric views?

Answer 18

isometric has all surfaces with equal angles of 120 degrees, diametric has 2 same angles, and trimetric has all 3 different angles

Question 19

What view should u use if you want to see features that are hidden on a Multiview drawing?

Answer 19

a section view because it gives a view of a cross section showing the features

Question 20

Why is using the auxillary view important?

Answer 20

It allows us to see the true surface of an inclined or oblique surface, instead of a isometric or perspective view it replaces it.

Question 21

What is the difference between a chain and baseline dimensioning?

Answer 21

Chain is when you start your dimensions from where you left off, while baseline is when you dimension everything starting at the outside edge

Question 22

What is the national standard for dimensioning?

Answer 22

ANSI y14.5

Question 23

What units do the US and the world use?

Answer 23

The US uses decimal inch, while the world uses millimeters

Question 24

What are the rules when dimensioning drawings using millimeters?

Answer 24

less than 1 use leading zeros, but don’t use trailing zeros
so like 0.1

Question 25

What are the rules when using inches for drawings?

Answer 25

less than 1, don’t use leading zeros, but add trailing zeros
.010 or 1.030

Question 26

What is a fundamental rule when dimensioning?

Answer 26

always include a tolerance

Question 27

Describe what a reference dimension looks like

Answer 27

it is a dimension that is enclosed by paratheses

Question 28

How do you dimension circles and arcs?

Answer 28

circles use diameter with a circle slashed with a line, while arcs use radius R

Question 29

What fonts are used in CAD?

Answer 29

century gothic

Question 30

look up the 14 gdrt symbols

Question 31

What does MMC or maximum material condition mean?

Answer 31

it is the condition of a feature that indicates the part reached it maximum amount of material

Question 32

Define the GD&T (geometric dimensioning and tolerancing)

Answer 32

it is a mathematical system used for 3d objects to describe the form, profie, orientation, and location within tolerance zones (basically the 14 gd&t symbols)

Question 33

How does point of contact change between primary, secondary, and teritary datums?

Answer 33

primary has 3 points of contact cause one plane sits on the object, while secondary has 2 points, and teritary has 1 point of contact

Question 34

define tolerance

Answer 34

it is the difference between the upper and lower limit, the amount of change that a object can change