Technical Drawing: Unlocking Computer Vision Through Technical Drawing

By Fouad Sabry

What is Technical Drawing

Technical drawing, drafting or drawing, is the act and discipline of composing drawings that visually communicate how something functions or is constructed.

How you will benefit

(I) Insights, and validations about the following topics:

Chapter 1: Technical drawing

Chapter 2: Computer-aided design

Chapter 3: Isometric projection

Chapter 4: Engineering drawing

Chapter 5: Orthographic projection

Chapter 6: 3D projection

Chapter 7: Axonometric projection

Chapter 8: Descriptive geometry

Chapter 9: Oblique projection

Chapter 10: Parallel projection

(II) Answering the public top questions about technical drawing.

(III) Real world examples for the usage of technical drawing in many fields.

Who this book is for

Professionals, undergraduate and graduate students, enthusiasts, hobbyists, and those who want to go beyond basic knowledge or information for any kind of Technical Drawing.

• Language: English
• Publisher: One Billion Knowledgeable
• Release date: May 13, 2024

Book preview

Chapter 1: Technical drawing

Technical drawing, drafting, or drawing is the act and discipline of creating diagrams that describe graphically how something performs or is created.

In order to effectively communicate concepts in industry and engineering, technical sketching is needed. People utilize familiar symbols, viewpoints, units of measurement, notation systems, visual styles, and page layout to make drawings easier to comprehend. Collectively, these rules establish a visual language and contribute to the clarity and readability of the artwork. ISO 128 is an international standard that specifies a number of the symbols and concepts of technical drawing.

Technical drawing is distinguished from expressive drawing in the visual arts by the need for accurate communication in the creation of a functioning document. The interpretation of artistic drawings is subjective; their meanings are multifaceted. It is known that technical drawings have one intended meaning.

A drafter, draftsperson, or draughtsman is a someone who creates drawings (technical or expressive). A professional drafter who creates technical drawings is occasionally referred to as a drafting technician.

A sketch is a rapid, freehand drawing that is typically not intended to be completed. Generally speaking, sketching is a quick approach to document an idea for future usage. Architect's sketches serve largely as a tool to experiment with new ideas and construct a composition prior to a more final work, especially when the finished work is expensive and time-consuming.

For instance, architectural drawings are a form of diagram.

Placing a piece of paper (or other material) on a flat surface with right-angle corners and straight sides, often a drawing board, is the fundamental drafting method. The T-square is then placed on one of the sides, allowing it to slide along the table's edge and across the paper's surface.

Simply move the T-square while drawing parallel lines with a pencil or technical pen along the T-edge. square's T-squares are used to hold devices such as set squares and triangles. In this instance, the drafter positions one or more triangles with known angles on the T-square, which is itself perpendicular to the table's edge, and can then draw lines at any desired angle to others on the page. Modern drafting tables have a drafting machine that slides over a big sheet of paper and is supported on both sides of the table. Because it is secured on both sides, it is ensured that lines drawn along the edge will be parallel.

In addition, the drafter utilizes a variety of technical drawing instruments to draw curves and circles. Principal among these are compasses, which are used to draw simple arcs and circles, and the French curve, which is used to draw curves. A spline is a rubber-coated metal that can be manually bent to conform to the majority of curves.

Drafting templates allow the drafter to create repeating objects in a drawing without recreating them from scratch each time. In the context of stagecraft, a lighting designer will employ the USITT standard library of lighting fixture symbols to denote the position of a common fixture in numerous settings. It is not rare for a drafter to build his own templates, in addition to the commercially available ones that are typically tailored to a certain job.

This fundamental drafting approach necessitates a precise table and regular attention to the placement of the tools. Allowing the triangles to push the top of the T-square down slightly, so throwing off all angles, is a typical mistake. Even simple operations like sketching two intersecting angled lines need multiple T-square and triangle motions, and drafting can be a time-consuming procedure in general.

A solution to these issues was the introduction of the mechanical drafting machine, an adaptation of the pantograph (often wrongly referred to as a pentagraph in these contexts) that enabled the drafter to swiftly obtain a precise right angle at any location on the page. Frequently, these machines offered the capacity to adjust the angle, so eliminating the need for triangles.

In addition to mastering the mechanics of drawing lines, arcs, and circles (and text) onto a piece of paper, drafting requires a thorough understanding of geometry, trigonometry, and spatial comprehension, and in all cases requires precision and accuracy, as well as a high level of attention to detail.

Although drafting is sometimes performed by a project engineer, architect, or shop employees (such as a machinist), skilled drafters (and/or designers) are typically responsible for the process and are in high demand.

The usage of computer-aided design technology has largely mechanized and accelerated the mechanics of the drafting process nowadays (CAD).

Two-dimensional (2D) and three-dimensional (3D) computer-aided design tools are utilized to generate technical drawings (3D).

2D CAD technologies, such as AutoCAD and MicroStation, have replaced the discipline of paper drawing. Within the software, lines, circles, arcs, and curves are formed. It is up to the user's technical drawing ability to create the drawing. When sketching first and third angle orthographic projections, auxiliary projections, and cross-section views, there is still considerable room for error. Simply put, a 2D CAD system is an electronic drawing board. Its biggest advantage over direct-to-paper technical drawing is the ability to make adjustments. In contrast to traditional hand-drawn technical drawings, in which a new drawing must be created from start if an error is discovered or a modification is required, the 2D CAD system allows a copy of the original to be modified, thereby saving considerable time. 2D CAD systems can be used to design blueprints for huge projects such as buildings and aircraft, but there is no method to verify that the various components will be compatible.

First, a 3D CAD system (such as KeyCreator, Autodesk Inventor, or SolidWorks) generates the geometry of the part; then, user-defined views of this geometry are used to generate the technical drawing. The software may generate any orthographic, projected, or sectional view. No room for error exists in the construction of these views. Setting the parameter for first or third angle projection and showing the appropriate symbol on the