Topic 7 Flashcards
(145 cards)
1
Q
A
2
Q
What is CAD?
A
Computer-aided design (CAD) is the process used to reproduce real life designs or design ideas virtually. It allows users to add several useful features such as adding materials, dimensions, or assembly notes.
3
Q
What are some capabilities of CAD?
A
CAD allows users to develop and modify their designs and simulate how different materials will look or perform in a particular design.
4
Q
List some advantages of using CAD.
A
- Ideas can be developed quickly.
- Drawings can be drawn quickly and changed easily.
- Designs can be viewed from different angles and with different materials.
- Ideas can be tested and modified before manufacturing starts.
5
Q
List some disadvantages of using CAD.
A
- Set-up is expensive.
- Users need to be skilled and trained.
- Technology is always changing, and users need additional training.
- Some updates and new software are expensive.
6
Q
What is BS 8888?
A
BS 8888 is a British Standard for technical product documentation, including geometric product specification, tolerance specification, and engineering drawings.
7
Q
What is the main purpose of BS 8888?
A
The main purpose of BS 8888 is to unify applicable International Organisation for Standardisation (ISO) standards for technical specifications.
8
Q
What does ISO stand for?
A
International Organization for Standardization.
9
Q
When was ISO founded?
A
ISO was founded in 1947.
10
Q
Fill in the blank: CAD allows users to _______ and modify their designs.
A
develop
11
Q
True or False: One disadvantage of CAD is that it allows ideas to be tested before manufacturing starts.
A
False
12
Q
What are the two main systems of measurement?
A
Metric and imperial units
The metric system is widely used globally, while the imperial system is still used in some countries, notably the UK.
13
Q
What is the metric unit for long length?
A
metre
The metric system uses the metre as the primary unit for measuring long lengths.
14
Q
What are the imperial units for long length?
A
mile, yard
The imperial system uses mile and yard as units for measuring long lengths.
15
Q
What is the metric unit for short length?
A
centimetre
The centimetre is commonly used for measuring shorter lengths in the metric system.
16
Q
What are the imperial units for short length?
A
foot, inch
In the imperial system, foot and inch are used for measuring shorter lengths.
17
Q
What is the metric unit for mass/weight?
A
gram
The gram is the standard unit of mass in the metric system.
18
Q
What are the imperial units for mass/weight?
A
ounce, pound
Ounce and pound are used in the imperial system to measure mass or weight.
19
Q
What is the metric unit for volume (liquid)?
A
litre
The litre is used in the metric system for measuring liquid volume.
20
Q
What are the imperial units for volume (liquid)?
A
gallon, pint, quart
These units are commonly used in the imperial system to measure liquid volume.
21
Q
What is the metric unit for volume (dry)?
A
litre
The litre is also used in the metric system for measuring dry volume.
22
Q
What are the imperial units for volume (dry)?
A
bushel, peck, pint, quart
These units are used in the imperial system for measuring dry volume.
23
Q
Who defined the metric system?
A
Gabriel Mouton
The metric system was defined by the 17th-century French scientist Gabriel Mouton.
24
Q
What is the full name of the SI system?
A
Système International
The metric system is also known as the International System of Units (SI).
25
How many countries predominantly use the metric system?
All but three countries
## Footnote
The U.S., Liberia, and Myanmar are the exceptions to the metric system usage.
26
What is a key characteristic of the metric system?
It relies on counting in tens, hundreds, and thousands
## Footnote
This decimal-based approach makes the metric system easier to use.
27
What are some examples of units in the imperial system?
inch, mile, pound
## Footnote
These units are fundamental in the imperial measurement system.
28
When was the British imperial system established?
1824 and 1878
## Footnote
The British Weights and Measures Acts established the imperial system.
29
When did the UK officially adopt the metric system?
1976
## Footnote
The UK began transitioning to the metric system in 1976.
30
Since when have UK companies been legally required to use metric units for fresh produce?
2000
## Footnote
This law mandates the use of metric measurements for the sale of fresh produce.
31
What are the two main categories of line types used in engineering drawings?
Visible and Hidden
32
Describe the application of continuous bold lines in engineering drawings.
Visible outlines, contours, and edges of an object
33
What type of line is indicated by short dashes and begins in contact with the originating line?
Hidden line
34
What type of line uses alternating long and short dashes?
Centre line
35
What is the purpose of a construction line in engineering drawings?
Used to construct layout work and hatching
36
List the three main parts of an engineering drawing.
* One or more views of an engineering component or assembly
* Dimensions, symbols, explanatory and instruction notes
* A title block
37
What information is typically included in a title block?
* Drawing reference number
* Author
* Drawing number
* Date
* Title
* Materials
* Scale
* Sheet number
* System of measurement
* Projection
38
Where is the title block usually located on an engineering drawing?
In the lower right corner of the drawing sheet
39
What additional information can CAD drawings' title blocks include?
* Name of CAD software
* Name of drawing file
* Units of the dimensions
40
What is the purpose of a border on an engineering drawing?
To demarcate the edge of the drawing region
41
What are trimming marks and where should they be placed?
Trimming marks facilitate trimming of the paper and should be placed at four corners
42
What is the function of centring marks on a drawing?
To facilitate positioning when reproduced
43
What does a frame do in an engineering drawing?
Limits the drawing space of the drawing sheet
44
Fill in the blank: Engineering drawings should be clear, concise, accurate and convey information about the size, shape, and _______.
[position of components]
45
True or False: The title block is not necessary for engineering drawings.
False
46
What is measurement tolerance?
The total allowable error within an item or range of values that is acceptable or permitted by the user from the result of the process or product measurement
## Footnote
Measurement tolerance accounts for the inherent inaccuracies in manufacturing processes.
47
What does tolerance refer to in manufacturing?
The acceptable range of difference that is agreed upon for parts of a product
## Footnote
Tolerance ensures that parts fit together correctly, allowing for slight variations in size.
48
What is the basic size?
Size from which the limits are calculated, commonly used for both the hole and the shaft
## Footnote
The basic size is usually the closest fraction.
49
What does the plus minus sign (+ or -) indicate?
How big or small the part must be to fit with the rest of the pieces
## Footnote
This symbol is crucial for ensuring that various components of an assembly are compatible.
50
What are the limits in the context of tolerance?
Maximum and minimum size that the part is allowed to be
## Footnote
Limits ensure that parts manufactured are safe and functional.
51
Why is tolerance important in engineering drawings?
It is important for safety and quality when manufacturing
## Footnote
Properly applied tolerances reduce mistakes and waste.
52
What happens if parts are not the right size?
Accidents could happen and customers would complain
## Footnote
Ensuring proper size is critical for both safety and customer satisfaction.
53
How can tolerances be stated?
For each dimension or apply to a drawing as a whole
## Footnote
Allowable tolerances do not have to be the same above and below the exact value.
54
What is an example of the maximum and minimum tolerance?
For 35 mm ± 0.25 mm, maximum is 35.25 mm and minimum is 34.75 mm
## Footnote
This shows how tolerances can be calculated for a given dimension.
55
What is upper deviation?
The difference between the basic size and the permitted maximum size of the part
## Footnote
Calculated as UD = |basic size – Dmax|.
56
What is lower deviation?
The difference between the basic size and the minimum permitted size of the part
## Footnote
Calculated as LD = |basic size – Dmin|.
57
What is fundamental deviation?
The closest deviation to the basic size, being the smaller of the upper and lower deviations
## Footnote
Fundamental deviation is critical for determining compliance with specifications.
58
What is an ellipse?
A plane curve tracing the intersection of a cone with a plane.
## Footnote
An ellipse is a specific type of conic section.
59
Define an elliptical arch.
An arch having the shape of half an ellipse.
## Footnote
Elliptical arches are often used in architecture for their aesthetic and structural properties.
60
In isometric drawing, how do circles appear?
Circles appear as ellipses and arcs as elliptical arcs.
## Footnote
This is due to the nature of isometric projection, which distorts shapes.
61
What does the isometric scale apply to?
Diameters and radius too.
## Footnote
The isometric scale helps in accurately depicting lengths in isometric drawings.
62
When do angles project true size in isometric projection?
When the plane containing the angle is parallel to the plane of projection.
## Footnote
If not, angles can appear distorted.
63
Do angles in isometric projection appear in true size?
No, angles never appear in their true size.
## Footnote
Even 90° corner angles appear distorted.
64
What angle should isometric drawings be drawn with?
A 30° angle at each side.
## Footnote
This standardizes the appearance of edges in isometric projection.
65
What is isometric projection?
A method for visually representing three-dimensional objects in two dimensions in technical and engineering drawings.
## Footnote
It helps in understanding complex shapes by simplifying them.
66
What is the relationship between the angles in isometric projection?
All angles between the axonometric axes are equal.
## Footnote
This equality is fundamental to maintaining the proportions of the projected object.
67
How are parallel edges represented in isometric projection?
Parallel edges are projected as parallel lines.
## Footnote
This characteristic helps viewers understand the object's geometry.
68
At what angle are horizontal edges drawn in isometric projection?
At a 30° angle.
## Footnote
This drawing technique is essential for achieving the isometric perspective.
69
How are vertical edges drawn in isometric projection?
As vertical lines.
## Footnote
This maintains the upright appearance of the object.
70
How should an object be oriented to produce an isometric projection?
So that its principal edges make equal angles with the plane of projection.
## Footnote
This orientation is crucial for accurate representation.
71
What angle do the edges of a cube make with each other in isometric projection?
They make equal angles of 120° with each other or 30° with a horizontal line.
## Footnote
This ensures uniformity in the projection.
72
What is the isometric scale ratio for actual lengths?
The actual lengths of the objects are reduced in the ratio of 2:3.
## Footnote
This ratio simplifies the drawing process.
73
What is the isometric length in relation to the actual length?
Isometric length = 0.816 actual length.
## Footnote
This conversion factor is vital for accurate scaling in isometric drawings.
74
What is the purpose of the isometric scale?
To facilitate the easy and quick method of measurement of lengths of the various edges in their reduced sizes while drawing isometric projections.
## Footnote
It allows for direct measurement without complex calculations.
75
What is first angle projection?
In first angle projection, the object is placed in the first quadrant, meaning it is placed between the projection plane and the observer. The right side of the object is drawn to the left of the elevation.
## Footnote
This projection method is commonly used in Europe.
76
What is orthographic projection?
Orthographic projection is a representation of three-dimensional objects in two dimensions, typically depicted in three separate views: front, top, and side view.
## Footnote
Other names for these views include plan, elevation, and section.
77
How many principal views are there in orthographic projection?
There are six principal views: front, back, top, bottom, left side, and right side views.
## Footnote
These views provide a comprehensive representation of the object.
78
What is the glass block method?
The glass block method is used to create the six principal views by placing the object in a glass box, projecting the image on the sides, and then unfolding the box to reveal the views.
## Footnote
This method helps visualize the orthographic views clearly.
79
What are the standard views used in an orthographic projection?
The standard views are:
* Front view
* Top view
* Right side view
## Footnote
The remaining views typically do not add new information but enhance clarity.
80
What is the difference between first angle and third angle projection?
The difference lies in the position of the plan, front, and side views on the drawing. In first angle projection, the object is between the observer and the projection plane, while in third angle projection, the projection plane is between the object and the observer.
## Footnote
This affects how the right side of the object is drawn in relation to the elevation.
81
In third angle projection, where is the object placed?
In third angle projection, the object is placed in the third quadrant, meaning the projection plane is positioned between the object and the observer. The right side is drawn to the right side of the elevation.
## Footnote
This projection method is commonly used in the United States.
82
Fill in the blank: The six principal views in orthographic projection are the front, back, top, bottom, and _______.
left- and right-side views.
83
True or False: The three remaining views in orthographic projection usually add new information.
False
84
What is the purpose of dimensions in engineering plans?
To provide size information of an object
85
What should dimensions refer to in orthographic projection?
Visible outlines on the part
86
What is a key rule regarding the number of dimensions provided?
No more dimensions than those necessary for complete definition should be given
87
When is scaling necessary in engineering drawings?
When drawings are too big or too small to be drawn at actual size
88
What is a ratio in the context of scaling?
A relationship between two quantities, expressed as the quotient of one divided by the other
89
What is the scaling ratio if a drawing is one-tenth of its actual size?
1:10
90
What is a full-scale drawing?
An engineering drawing created to the actual size of the object
91
What is the ratio of a full-scale drawing?
1:1
92
What defines an enlarging scale?
A drawing created larger than the actual size of the object
93
What is the ratio of an enlarging scale?
Larger than 1:1
94
What characterizes a reducing scale?
A drawing prepared smaller than the actual size of the object
95
What is the ratio of a reducing scale?
Smaller than 1:1
96
How should dimensions be arranged in engineering drawings?
For optimal readability if possible
97
What is the common metric unit of measure on engineering drawings?
Millimetre (mm)
98
How should the center of circles and holes be indicated?
By a cross
99
How is radius indicated in dimensions?
With an R
100
How is diameter indicated in dimensions?
With the symbol ∅
101
What should you draw from the edges of all shapes in the front view towards the right in step 2 of drawing the side view?
Thin dashed lines
102
In step 2 of drawing the side view, what should be drawn following the size guidance established by the dashed lines?
All the shapes included on the side view
103
What is the first step in drawing the front view?
Choose the view that shows more information about the object
104
What should be drawn in the front view?
The visible features of the front view
105
What should you draw from the edges of all shapes in the front view for the top view?
Thin dashed lines
106
What should be drawn in the top view following the size established by the dashed lines?
The visible features of the top view
107
What angle should the line be drawn at in step 1 of drawing the side view?
45º
108
What should be done when the thin dashed lines from the edges of the top view reach the 45º line?
Stop and draw vertical perpendicular lines towards the top
109
What is the first step in creating an orthographic projection?
Draw the front view outline as shown on the orthographic projection by drawing parallel lines to the isometric axes.
110
How do you create the side view in an orthographic projection?
Draw the side view outline as shown on the orthographic projection by drawing parallel lines to the isometric axes.
111
What is the procedure for drawing the top view in an orthographic projection?
Draw the top view outline as shown on the orthographic projection by drawing parallel lines to the isometric axes.
112
What is the next step after drawing the outlines in an orthographic projection?
Draw the details in the correct view as shown on the orthographic projection by drawing parallel lines to the isometric axes.
113
What must be added to complete the orthographic drawing?
Add the hidden lines necessary to complete the orthographic drawing by following the orthographic projection.
114
What is CAD used for?
CAD is used by designers, architects, engineers, and other professionals to complete their work and reproduce design ideas virtually.
## Footnote
CAD provides advantages and features that traditional design tools cannot.
115
What types of designs can CAD create?
CAD allows users to create designs in either 2D or 3D.
## Footnote
This helps users visualize the construction.
116
What is the finite element method (FEM)?
FEM is a numerical method that provides solutions to complex problems by dividing them into smaller, manageable 'finite elements'.
## Footnote
It is used when mathematical equations are too complex to be solved in a typical manner.
117
What is the primary purpose of FEM?
FEM provides engineers insight into the structural behaviour of designs to locate weak points and improve them.
118
When was FEM developed?
FEM was developed in the 1950s.
## Footnote
It was created to help model and analyze complex systems in various engineering fields.
119
What foundational concepts is FEM based on?
FEM is based on the concepts of mechanics, including Newton's laws of motion, conservation of mass and energy, and equilibrium.
120
What types of problems can FEM be applied to?
FEM can solve thermomechanical, chemical, biomedical, and fluid behavioural problems.
121
How is CAD related to FEM?
CAD defines the three-dimensional shape of an object and can separate the different elements of this object.
122
What is finite element analysis (FEA)?
FEA is a computerized method for predicting how a product reacts to real-world forces, vibration, heat, fluid flow, and other physical effects.
123
How does FEA work?
FEA breaks down a real object into a large number of finite elements and uses mathematical equations to predict the behaviour of each element.
124
What are some applications of FEA?
FEA can simulate strain, temperature, vibration, and physical properties of materials.
125
What is a practical application of finite element modelling software?
Fluid dynamics is a practical application where engineers analyze and solve problems related to the flow of fluids.
126
What does fluid dynamics study?
Fluid dynamics studies the flow of liquids and gases and their interaction with surfaces.
127
What kind of simulations can fluid dynamics perform?
Fluid dynamics can simulate how airplane wings perform, the impact on a space shuttle crossing the ozone layer, or how petroleum flows through pipelines.
128
What are the benefits of FEA and FEM?
Benefits include improved design accuracy, identification of weak points, and optimization of materials and structures.
129
Name two software used for FEM and FEA.
* ANSYS
* Abaqus
130
Fill in the blank: FEA is used to predict how a product reacts to _______.
[real-world forces, vibration, heat, fluid flow and other physical effects]
131
True or False: FEA uses physical models to conduct simulations.
False.
132
Define finite element analysis (FEA) in your own words.
FEA is a technique that uses numerical methods to predict how structures respond to various physical forces.
133
Define finite element modelling (FEM) in your own words.
FEM is a method that simplifies complex structures into smaller parts to analyze their behaviour under different conditions.
134
What are some uses of 3D printing?
* Consumer and industrial products
* Dental products or prosthetics
* Architectural scale models and maquettes
* Reconstructing fossils
* Replicating ancient artefacts
* Reconstructing evidence in forensic pathology
* Movie props
## Footnote
These applications demonstrate the versatility of 3D printing across various fields and industries.
135
What is CAM?
Computer Aided Manufacturing (CAM) uses software and computer-controlled machinery to automate a manufacturing process.
## Footnote
CAM is essential for modern manufacturing, enabling precision and efficiency.
136
What are the three components required for a CAM system to function?
* Software that generates toolpaths
* Machinery that turns raw material into a finished product
* Post processing that converts toolpaths into a machine-understandable language
## Footnote
These components work together to automate the manufacturing process effectively.
137
Define toolpath in the context of CAM.
The path through space that the tip of a cutting tool follows on its way to producing the desired geometry of the workpiece.
## Footnote
Toolpaths are crucial for achieving precise cuts and shapes in manufacturing.
138
What is one-off production?
One-off production is when only one product is made at a time, often requiring a high level of skills and being highly specialized.
## Footnote
This type of production is usually expensive due to the skill and time involved.
139
What is batch production?
Batch production involves making small quantities of products, often using machine tools, and is more cost-effective than one-off manufacturing.
## Footnote
This method can respond quickly to consumer demand due to its flexibility.
140
Describe mass production.
Mass production is typically carried out on an assembly line by machines and robots, requiring a high initial investment but producing large quantities of products.
## Footnote
CAD engineering programs are used to create detailed manufacturing diagrams for production lines.
141
What is 3D printing?
3D printing is the creation of three-dimensional solid objects from a digital file using additive processes that layer material to form an object.
## Footnote
Each layer represents a thinly sliced cross-section of the final object.
142
List some advantages of 3D printing.
* Ability to print complex shapes and interlocking parts
* Greater flexibility in production
* Reduction in production time, waste, errors, and costs
* Verification of designs through 3D prototypes before production
## Footnote
These advantages make 3D printing increasingly popular in various industries.
143
List some disadvantages of 3D printing.
* High costs
* Significant energy requirements
* Limitations in scale and speed
* Accuracy issues
* Potential for counterfeiting and illegal activities
* Job obsolescence in manufacturing
## Footnote
These disadvantages highlight the challenges and risks associated with adopting 3D printing technology.
144
True or False: 3D printing can be used for counterfeiting and illegal activities.
True
## Footnote
The lack of regulation in 3D printing technology poses ethical and legal concerns.
145
Fill in the blank: 3D printing is a _______ technology that can disrupt traditional manufacturing jobs.
disruptive
## Footnote
This characteristic of 3D printing can lead to significant changes in the job market.
