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UNIT 4 - SECTIONAL DRAWINGS
In addition to drawing the minimum 3 views of an object as you learned in Unit 3, which illustrate what the object looks like on the outside, with some reference to some hidden interior characteristics such as holes, notches etc. Sectional Views are needed.
Sectional Views show how and what the object is made of, on the inside. This includes parts and materials that can't be seen from the outside. much like slicing an apple in half, revealing the inner core and seeds not visible from the outside.
There are various types of Sections, but the most common are Full Sections and Offset Sections. Full Sectional Views are used primarily when an object is symmetrical along an axis or when a straight 'cutting plane' can reveal the most about the objects interior characteristics.
Watch the short video below to better understand the types of sections and how the 'cutting plane' location is used to determine what is shown in the Sectional View including the material the object is made of, which will be further explained in class.
Once a 'cutting plane' is established and drawn on the Top View, lines are projected from each point it intersects with the object lines as shown in the example at right. This applies to all types of Sections as shown in the video. Offset Sections are used when all of the parts of an objects interior can't be shown with a straight line as in a Full Section. The material that the object is made of is then denoted using various patterns or 'hatching'. Only the portion of the object that the cutting plane passes through will be hatched inside the object lines which are drawn darker around the portion in section, also known as Section lines as shown in the examples at right.
OFFSET SECTION
ASSIGNMENT 1 - Using CAD, draft 3 views as you did in Unit 3, of the object at left, AND a Full Sectional view corresponding to a cutting plane through the center of the object designated with a centerline on the Top View. The Cbore hole is 1/4" deep.
The object is made of plastic as you should indicate with hatching in the Sectional View.
DUE - 11/15/24
ASSIGNMENT 2 - Using CAD, draft 3 views as you did in Unit 3, of the object at right, AND an Offest Sectional view corresponding to a cutting plane through the center of each of the holes on the lower half of the object, and through the center of the counterbore hole. The object is made of cast iron as you should indicate with hatching in the Sectional View.
The object is 4" wide, 8" long and the base is 3/4" thick.
The total height including the round part is 3".
The small holes are 3/4" diameter and are 1" from each corner to the center of the hole.
The round part that 'sticks up' is centered on the object both ways and has a diameter of 2 - 1/2" and a counterbore hole of 2" diameter that is 1/2" deep.
The hole in the center is 1 - 1/2" diameter.
DUE - 11/21/24
TOP VIEW
SIDE VIEW
END VIEW
TOP VIEW
SIDE VIEW
SOME COMMON HATCH PATTERNS
ASSIGNMENT 3 - Using CAD, draft 3 views as you did in Unit 3, of the object at right AND a Full Sectional view corresponding to a cutting plane through the center of each of the holes. The object is 11" long and 5.5" wide. Convert the other dimensions accordingly.
The object is made of steel as you should indicate with hatching in the Sectional View.
DUE - 11/26/24
TOP VIEW
SIDE VIEW
END VIEW
ASSIGNMENT 4 - Using CAD, draft 3 views as you did in Unit 3, of the object at right AND an Offset Sectional view corresponding to a cutting plane through the center of each of the holes. The radius of the left side is 1" and the diameter of the large circular part is 1-1/4" and the hole diameter is 3/4".
The total height is 1-1/2". The base height is 3/8". The length from center to center is 3-3/4". The radius of each of the right sides is 5/8", the diameter of the 2 holes are 3/8" and they are 5/8" from the center of the object to center of the holes.
The connecting arm is 1/4" wide and the fillets are 1/8" radius.
The object is made of aluminum as you should indicate with hatching in the Sectional View.
DUE - 12/4/24
ASSIGNMENT 5 - Using CAD, draft a Top View and 1 Side View of the object at right AND an Aligned Sectional view corresponding to a cutting plane as shown with center lines with the vertex being the center of the object.
The diameter of the large circular parts are 3-1/2" and 3-1/4". The diameters of the inner part are 1-1/2" and 1". The total height is 1-1/2". The outer ring is 1-1/4" high.
The width of the spokes are 1/2" and thickness is 1/4".
The notch in the center is 3/8" wide and 1/8" deep.
Fillets are 1/8" radius.
The object is made of lead as you should indicate with hatching in the Sectional View.
DUE - 12/10/24
ASSIGNMENT 6 - Using CAD, draft a Top View and 1 Side View of the object at right AND an Aligned Sectional view corresponding to a cutting plane as shown with center lines with the vertex being the center of the object.
The diameter of the large circular part is 3-1/2" and the 5/8" diameter holes are centered in a 2-1/4" diameter.
The diameters of the inner part and hole is 1-1/4" and 3/4".
The total height is 2". The base is 1/2" thick.
The notch in the center is 1/4" wide and 1/8" deep.
The object is made of brass as you should indicate with hatching in the Sectional View.
DUE - 12/13/24
ASSIGNMENT 7 - Using CAD, draft 3 Views AND a Fulll Sectional view with dimensions on the appropriate views.
The object is made of rubber as you should indicate with hatching in the Sectional View.
DUE - 12/18/24
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EXTRA CREDIT CHALLENGE - Using CAD, draft 3 Views AND a Fulll Sectional view with dimensions on the appropriate views.
The object is made of steel as you should indicate with hatching in the Sectional View.
DUE - 1/10/25
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CLICK HERE TO TAKE THE UNIT 4 QUIZ
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