Indrouction To Conical Layout Flashcards
Most radial line development begins with establishing the elevation veiw and then extending the side lines until they meet at a common point called the: _________________.
Apex Point.
How many methods are used to establish the vertical apex?
Two
State the mathematical fomula to establish the vertical apex.
Vertical Height (VH) × Large Diameter(LD)
Vertical Apex(VA)= -----------------------------------------------------------
Large Diameter (LD) - Small Diameter(SD)When building a storm collar, the _______ _________ would be measured as this is the critical diameter in which pipe will have to pass through.
Small Diameter
_______ _________ are conical objects that are used to divert water away from the opening of roof jacks.
Storm Collars
Four functions of a rain cap.
- To coordinate with the design of the building.
- To keep birds, leaves and other materials out of the stack with the aid of a screen or mesh.
- To prevent rain or snow from entering the stack.
- To allow a free flow of air.
State the method of determining the height of a rain cap.
1/2 D of the pipe.
The outside Diameter of the cap must be a distance equal to ______ _______ the diameter of the pipe.
Two Times
State the formula to calculate the conical cap cut-out.
Conical cap cut-out = 6.28 x X
Caculate the following measurements for a rain cap using 8” round pipe.
- Cap height:
- Cap opening:
- Cap height above the pipe:
- 4”
- 8”
- 4”
What is the definition of a cone?
The definition of a cone is that it is a 3 dimensional object with a circle for a base that tapers to a point.
What is the best method of cone development?
Radial line development for right cones whenever possible. This is the most accurate method.
What seam can be used to fabricate a section or join sections of a project?
The lap seam can be used both as a seam or a joint between sections.
What are four types of seams used to join sections of a project?
Lap seam, peened seams, double peened seams, hammerlock seam, elbow seams.
What are three edges used on conical projects?
Wired edge, raw edge, hemmed edge, capped edge.
How is the curve formed on cones that are too large for the roll forming machine?
Step braking is a method used for large curves.
How is the curve formed on cones that are too large for the roll forming machine?
Step braking is a method used for large curves.
What is the preferred method for forming curves for conical projects?
If at all possible, the roll forming machine should be used to form the cone.
Smaller cones are not able to be formed in the roll forming machine. How can these cones be formed?
To finish the forming on these cones, a stake must be used.
Why are there different sizes of turning rolls?
Because different Diameters of wires are used for wired edges, different sizes of turning machines are used.
What should the gauge of the turning machine be set for?
The gauge on the turning machine should be set to 2 1/2 x (Diameter) of the wire, from the center of the top wheel to the gauge.
What should the gauge of the wire machine be set at?
The gauge should be set at a distance of 1 wire Diameter plus 2 metal thickness, from the inside of the top wheel.
When forming a wired edge with the turning machine, the edge is flared out by tightening the crankscrew after each revolution of the project.
A. True
B. False
B. False;
The crankscrew should not have been tightened throughout this procedure.
What machine is used to finish the wired edge on a funnel?
Once the material is dressed tightly, it can be tucked under with the wire machine.
What should be accounted for when developing the patterns for round to round reducer?
When developing the pattern for the body, the airflow and big/small end should be accounted for.
The body of a pail must be made in two parts.
A. True
B. False
B. False;
The body of the pail can be made in two parts or in one part.
How is the body of a roof jack often joined to the flashing?
This is often a hammerlock seam.
What is a bail?
The bail is the name given to a piece of wire that is used as a handle for a sheet metal project.
How long should the wire for a bail be cut?
The standard for a bail is to cut a length of wire equal to twice the diameter of the project.
What is the simplest type of bail ear?
The simplest type of bail ear is a hat channel that is attached to the side of the project.
Which of these files would be the coarsest?
A. Dead smooth
B. Second cut
C. Bastard
D. Smooth
C. Bastard
What would we use to transfer patterns onto sheetmetal.
A. Aligning punch
B. Centre punch
C. Hollow punch
D. Prick punch
D. Prick punch
It is dangerous to use chisels that have:
A. Hard point
B. Mushroomed heads
C. Ruff edges
D. Long handles
B. Mushroomed heads
What hammers would we use on a brake?
A. Wooden mallet
B. Body hammer
C. Ball peen hammer
D. Riveting hammer
A. Wooden mallet
Water ladder is the best choice for working around electricity?
A. Aluminum
B. fiber glass
C. wooden
D. copper
B. Fiber glass
Water ladder is the best choice for working around electricity?
A. Aluminum
B. fiber glass
C. wooden
D. copper
B. Fiber glass
When using a full face safety visor, safety glasses are not required.
A. True
B. False
B. False
