Introduction

Simple and Straight Line Pattern Development

1. Intro
   1. Introduction-When we are referring to simple and straight line pattern development, we are referring to patterns which are made up of a series of lines on a 2D piece. These lines will create a pattern and a 3D object, but it’s done with no true “pattern development”. Think of a box. If we draw all 6 sides of a cube, flat, it can be folded to make a box. We have created a pattern, but we haven’t really “developed” it. We just drew 6 squares attached together. This is the most basic, but probably the most important of our layout skills. Everything we make takes layout and being able to accurately and effectively produce these simple patterns, is a fundamental skill of a sheet metal worker. We will focus on the layout of duct fittings in this unit.

1. Objectives
   1. Understand the techniques used to develop patterns for duct fittings

2. Layout Terms
   1. Blank size-A rectangular piece which encompasses the largest dimension, both horizontally and vertically, of a part
   2. Cheek-The 2 matching pieces of an elbow or ogee offset. Commonly referred to as the top and bottom

• Duct fitting-A piece of duct that changes size or direction of airflow or a combination of both

1. Heel-The side which joins the outside perimeter of the cheek
2. Throat-The side which joins the inside perimeter of the cheek
3. Wrapper-The part of an ogee offset which joins the cheeks