Parallel Line Development Flashcards
A line used to divide an object into sections when developing patterns for round or irregular shapes, drawn on the elevation view at their true length-
Element line
A pattern with allowances added for fabrication-
Gross pattern
A line used to project an element point from one view to another-
Projection line
A point on the stretchout that represents the distance between element points from plan view-
Step off distance
A pattern with no allowances added-
Net pattern
Names used to identify extra element points related to another point-
Primes
The line where 2 parts of an object meet, usually at an angle-
Miter line
View of an object from the side-
Elevation view
When top and bottom halves of a view are identical, this can be used as a shortcut for round layout?
Half plan view
The actual length of a line usually found in elevation view?
True length line
View of an object from above or below-
Plan view
How many views are required to perform parallel line development?
2
A projection line is drawn in __________________ weight?
Construction
How many spaces are typically used when dividing a plan view into equal spaces?
12
What view is used to lay out a hole pattern?
Elevation view
Another name for the length of a pattern?
Stretchout
What method is used in parallel line development to divide the stretchout into 12 equal spaces?
Sloped rule
What type of fitting is the intersection of two pipes at an angle?
Pipe tee
What type of cylinder has the bases parallel to each other but the sides are not perpendicular to the bases?
Oblique cylinder
Objects with a constant cross section can be developed with parallel line, true or false?
True
When describing a pipe tee, you first state the ____________ size and then the main branch size?
Stub
It is always best to start where when numbering the 12 equal divisions on a stub pattern?
At the seam
When laying out a tee fitting, you start by drawing what view?
Side elevation
Corresponding element lines from the end view and side elevation create what?
Mitre line
The process for laying out a wye and a tee are the same, true or false?
True
What is the purpose of an offset?
To bypass a permanent obstruction either vertically or horizontally
When manufacturing an offset, the length should be a minimum of how long in relation to the offset amount?
Minimum twice as long as the offset amount
Angle divided by the number of pieces x 2 -2 is what formula?
Mitre angle formula
The most accurate method to establishing a mitre line is what?
Bisecting (trisecting) an angle
After establishing a mitre line, what can be used to ensure the angle is correct?
Protractor
3.14 x diameter =
Stretchout
If your mitre line was developed at 15 degrees, what would be the included angle of a middle gore?
30 degrees
How many methods are there to lay out an offset?
4, (given throat, given heel, given centreline, bisecting the centreline)
What 3 pieces of information must you know to lay out an offset?
Offset amount, opening size and vertical height
What method is used to transfer the length of the element lines on the elevation view to the stretchout in parallel line development?
Projection
When calculating small end on a fitting, always round __________ when converting from decimal to fraction?
Up
What is always marked on the pattern to aid in the fabrication process?
Centreline
What is the stretchout for a 7” LE with a 1/2” lap seam?
22 1/2”
How is the stub developed for a rectangular on round pipe tee?
Divide plan view into equal increments
What is the minimum number of points required to develop a curve?
3
How many supports does a roof jack require?
Three supports
What method of development is used for oblique and right cylinders?
Simple layout
Parallel line development
Triangulation
Radial line development
Parallel line development
How do you calculate the tee stub stretchout on a rectangular tee?
2L + 2W (length + length + width + width)
Calculate the mitre angle for a 4 piece, 3”, 90 degree elbow?
15 degrees
Calculate the mitre angle for a 3 piece, 4”, 45 degree elbow?
11.25 degrees
