Sketches - Part A & B Modules Flashcards
Orthographic Projection
A method of representing a 3 dimensional object on a print in a way that shows all important sides
What are the 6 different views of Orthographic Projection
Front, right side, left side, top (plan), bottom & rear
What is the standard text for a drawing?
upper case gothic
What are the 8 different lines on drawings?
Visible or object line, centre line, hidden line, extension line, dimension line, leader line, cutting (viewing) plane & phantom line
Object Line
A thick dark line, structural outline and the most common
Center Line
Dotted line with one longer line and then a short one. Shows the centre of the object
Hidden Line
a regular dotted line. shows a part of the object that is hidden from that particular view
Dimension Line
a thin line with an arrow on each end. Used to place the dimensions
Extension Line
a short line that shows the start and end point for the dimension lines.
Leader Line
a thin line that ends with an arrow. Leads you from information or a dimension to a particular area
Cutting Plane
thick, dark lines either broken or continuous with arrows are right angles at each end. It shows where a sectional view was taken from
Phantom Line
A thin broken line with a long dash followed by two short dashes. It shows a mating part, assembly or movement of an object
Third Angle Views in order
Front view, top view placed above it, the right put on the right, left on the left, bottom on the bottom and rear is placed on the far left
First Angle views in order
Front view, top view put on the bottom, right on the left, left on the right, bottom on the top and rear on the far left
What are the 3 types pictorial views?
Perspective, Oblique & Isometric
Perspective view
Most common in architecture or construction and uses a vanishing point
Oblique view
uses a distortion method thats hard to read
Isometric view
Most common and uses good, easy to read pictures
Describe how to read Third Angle Views
When you look at the view from the front you place that drawing on the paper first, then you look at the object from the top and you put what you see on the top of the frontal view drawing. Then you look at the drawing from the right side and put what you see to the right of the frontal view
Describe how to read First Angle Views
When you look at the front of the view you draw to out as you see it. When you look at the view from the top you draw what you see as if you were looking right through the object and so you draw it under the frontal view. Same for the right view, you draw it as if you were looking right through the object and so you draw it on the left side of the frontal view
What are 4 most common material sectional views for metals?
Steel, Cast Iron, Aluminum & Brass/Copper
What does the material sectional view for steel look like?
2 lines cross together and then a space and the 2 lines close together again
What does the material sectional view for Aluminum look like?
Lines spaced out crosses on each line going in the opposite direction
What does the material sectional view of Cast Iron look like?
regular lines with the same spaces between each line
What does the material sectional view of Brass/Copper look like?
one solid line then a dotted line then another solid line
What is a Chamfer?
A beveled edge on the edge of a shaft to make the end smaller or on the opening of a hole to make the opening larger
What are the 3 types of dimensioning?
Unidirectional, Aligned & Dual Dimensioning
Unidirectional
dimension numbers are all in one direction and easy to read compared to Aligned
Aligned dimensioning
dimension numbers are aligned with the dimension line and the numbers for vertical are placed on the left
Dual Dimensioning
shows dimensions in metric and imperial
Name 3 different kinds of threads on a drawing?
Simplified, schematic and pictorial. Simplified is the most common as the other 2 take much longer for the engineers to draw
If you were to see a bolt described like this 3/4-10 UNC-2A what does it mean?
Imperial - 3/4 is the diameter, 10 is the # of threads per inch, UNC is the type of thread, 2 is the pitch, A is external thread
If you were to see a bolt described like this M16x2x25?
M is metric, 16 is diameter, 2 is pitch and 25 is length
What is thread pitch?
The distance from one thread groove to the next,
What is a fillet and its purpose?
A curved feature on an inside corner. Its purpose is to relive stress or increase strength
What is a ‘round’?
an external radius
What is a spot face?
Similar to a counterbore but has no specific depth. Used to provide a flat seat for a bolt or washer
What is a Woodruff Keyseat?
A shaft key that has a semicircular shape and fits into a semicircle keyseat in a shat and a rectangular keyway in the hub
What are 2 types of bearings?
Anti-friction and plain
What is an anti-friction bearing?
Has some the of rolling element between the inner and outer ring
What is a plain bearing?
a sleeve or liner placed between moving shaft and a housing to eliminate wear
What is “free length” on a spring?
the length of the spring when it is under no load or stress
How do you tell what ‘S’ shaped structural steel is?
Its the shape of a capital I and measures from the flange face to the flange face. You can see the dotted line going from the top to the bottom
Rounding off by cutting away the inside or outside corner of an object is called what?
radius
How do you recognize the symbol for W shaped structural steel?
measures the flange width, flange thickness and the web thickness. Looks like an ‘I’ but has an extended top and bottom
How do you recognize the symbol for C shaped structural steel?
Looks like a C and measured from flange face to flange face
How do you recognize the symbol for L shaped structural steel?
Has an equal leg (same length as the vertical leg) and unequal leg (a regular capital L) When it is written the first number lists the length of the longer leg and the second is the other leg
What does HSS means?
Hollow Structural Steel. Can be round, square, rectangle
How do you recognize the symbol for Welded Wide Flange shaped structural steel?
Same ‘I’ with extended top and bottom measuring from flange face to flange face
What are cutting lines?
They indicate where the sectional view came from. The arrows on the end of the line indicate which direction you look when viewing the sectional drawing
What are breaking lines?
They allow long shaft like shapes to be drawn in less space so that the drawing can be drawn to a larger scale for clarity
What is symmetry?
A line that shows that a part is the same on either side of the line.
What are sectional drawings?
They let you see inside the workpiece to understand the internal shapes and features of the workpiece far better than you could just with the use of a hidden line.
What are the 7 sectional views in drawings?
Full, half, removed, revolved, broken out, offset & aligned.
What is a taper?
The difference between the large and small diameters
What is the amount of taper, usually specified as 1 for a particular unit of length?
Taper Ratio
Name the 7 elements you can use to define a taper?
Large diameter, small diameter, length of taper, taper per foot, taper per inch, taper ratio, included or center line angle.
When is it not necessary to specify the angle of a chamfer?
When the chamfer is an external chamfer of 45 degrees
What is the angle of a countersink?
82 degrees
