Simple Layout

5 methods of pattern development

1. simple layout

2. parallel line development

3. radial line development

4. triangulation line development

5. rollation line development

What is simple layout?

Patterns that are drawn directly onto metal without using any orthographic views or formal development methods are referred to as simple layout.

What is parallel line development?

A method used in sheet metal layout and fabrication to find the true shape (flat pattern) of a 3d object

what is radial line development?

Objects whose sides meet at an apex, or common center point, may be developed using radial line development. All lines must radiate from a common center.

What is triangulation development?

is a method of pattern development used to develop patterns for irregular shaped objects. The surface of the object to be developed is divided into a series of triangles laid side by side.

What is Rollation development?

a shortcut method used when accuracy is not a concern but speed is. A model of the object is to be developed and is rolled on to metal to produce the pattern.

When laying out duct what should brake lines have whenever possible?

A capital X to resemble that it’s a break line as well as a the direction the break is to be folded (also in capital letters)

How do you figure out the stretchout length of a round pipe?

3.14 multiplied by Diameter of the pipe.

What is a raw edge connection?

no allowances are added to the completed pattern. raw edge is used when duct or fittings are welded together.

What is the allowance for a grooved seam?

The allowance is three times the width of the grooved seam. The width of the grooved seam varies depending on the project being fabricated.

What is the allowance for a Pittsburgh Male hook for rectangular and round, and what is the allowance for the female pocket?

Male hook for straight duct is 1/4”

Male hook for for radius pieces is 3/16”

The female pocket is 15/16” (Sait) or 1”

What side of the duct is a female pocket typically placed on?

The shorter side of the duct.

What is the difference between Net Pattern and Gross Pattern

Net pattern is the 2D pattern laid out for 3D construction. Gross pattern is the net pattern with allowances added.

Most often what is the depth of a notch when notching a piece of duct?

3/4”

Patterns that are drawn directly onto the metal without using any orthographic views or formal development methods are referred to as?

Simple layout

Many objects that have one pair of parallel sides can be developed using?

parallel line development

objects whose sides meet an apex, or common center point may be developed using?

Radial line development

_______ is used a method of pattern development used to develop patterns for irregular shaped objects

Triangulation

_____ is a shortcut method of Layout

Rollation

The ______ of a pattern is the distance around the duct

Stretchout

The vertical lines that become the corners of the duct after it is folded in a hand brake are called?

Brake lines

______ _________ are used to join individual pieces of duct or fittings together.

Duct connections

The _____ _________ requires no allowances to be added to the completed pattern

Raw edge

The S- cleat and Drive cleat connections also called the slip and drive or S&D connection, is a common connection used for connecting?

residential or smaller commercial ducts

S cleat is approximately how wide?

1”

The drive cleat is how wide

1 1/8”

The s&d connection requires what allowance to be added to the duct connection?

1/2”

The standing drive connection is also called the?

CP connection

Hammer lock is also called?

Tap-in

What is a hooked seam with a single offset called?

Grooved Seam

What is the most common machine formed lock in the sheet metal trade?

The pittsburgh lock

What is required to remove excess material not required in either the duct fabrication allowances or the duct connection allowance?

Proper Notching

The slip and drive connection only require what size to be added to the edge of the duct or fitting

1/2”

The duct notch, radius fitting notch and the transitional fitting notch are all are all notches used when notching for the _____ duct connection.

S&D