Lesson 1_2_3 INTRODUCTION TO TECHNICAL DRAFTING
- 1. Technical Drafting ALLPPT.com _ Free PowerPoint Templates, Diagrams and Charts
- 2. Drafting Drafting is said to be the universal language of industry and modern technology. It is through the application of special lines and symbols that drafter’s use so that technical people can communicate. Through drawings, ideas and designs are transferred between draftsmen, architects and engineers. The uniformity of lines and symbols makes it possible to be widely accepted, thus, making graphic technical drawing understandable anywhere in the world. In a fast-developing country like the Philippines, many investors are coming in so they need technical people to supervise factories and offices. New products are introduced; hence, there is a great demand for designs. The production of goods always starts from a design. Ideas are presented by pictorial sketches in the initial stages of creative work. Detailing is done with lines to represent all the features of an object, such as its edges, surfaces and contours. Lines also form the sizes, dimensions, symbols and notes to complete a description. To understand the fundamental principles of drawing, acquired desirable values are necessary. A draftsman should possess the ability and the skills in using different drawing instruments. In general, it helps him construct output
- 3. CAREER OPPORTUNITIES IN TECHNICAL DRAFTING Individuals with technical drawing careers are known as drafters. They convert specifications and sketches created by architects and engineers into mechanical drawings and blueprints. Construction and production staff then use these plans to create structures and equipment. Drafters typically work indoors and regular business hours, although overtime is possible when project deadlines approach.
- 4. QUALIFYING SKILLS THAT ANY DRAFTSMAN MUST POSSESS: He must have the ability to interpret a working drawing. He must know how to read symbols. He must understand the alphabet of lines and drawing specifications. He must have the ability to draw different styles of letters. He should know how to draw and apply different shades in coloring.
- 5. 1.USE OF TOOLS AND EQUIPMENT There are a great variety of drafting materials and tools used in technical drafting. The drafting materials and tools discussed in this module include most of the basic ones but sufficient enough for your initial understanding about mechanical drawing. Drawing Board -A portable board made of softwood, wherein a drawing paper is fastened on top. Their working edge should be perfectly straight and their surface is trim and smooth. A. Tools, Instruments and Equipment
- 6. Triangles – they are usually made of transparent plastic which are used for drawing oblique and vertical lines. Triangular Scales -English Scales -Metric Scales -they are made of wood, plastic or metal, which are used for drawing an object on a paper by scaling the sizes.
- 7. Protractor -Is used for measuring and laying out arcs and circles as well as angles that cannot be measured with either the 45°or the 30° x 60° triangles. It is half-circle shaped instrument, made of transparent plastic used for guiding a draftsman in drawing different angles. Compass -Is used for drawing arcs and circles. It is made of the lower portion of the pencil leg. It is removable and to be replaced when needed. The pen and the needle point leg are held together by a handle.
- 8. T-square -Is an instrument used for drawing horizontal lines. It is also used to support the triangle for drawing vertical or inclined line.Are made of wood, plastic or metal. Two Main Parts of T-square Three kinds of T-square - The head - fixed heads - The blade - removable head - adjustable head Drawing Set It is a kit which consists of a ruling pen, compass pen and pencil leads. It is used for drawing arcs and circles and inking them - one of the most important tools of a draftsman, used for drawing
- 9. Ruler -It is made of wood, plastic or metal used for measuring purposes and for drawing and for drawing a straight line. The edge of the ruler should be straight. Eraser - This is used to clean the dirt off the drawing. A soft eraser is advantageous in removing smudges and pencil marks, whereas, a harder eraser is useful for making changes and correcting errors in the drawing.
- 10. Erasing Shield - This tool is made up of metal with irregular holes. It is a useful tool to protect the rest of the drawing when clearing up smudges, unnecessary pencil lines and other erasures. Divider - This is a drawing instrument used when transferring measurements, dividing lines and arcs into the desired number of equal parts.
- 11. B. Materials Drawing Paper / Tracing Paper -It should have a smooth surface when erasures are made. Tapes and Tacks -There are varieties of tapes and tacks available in the store. They are used for fastening the drawing paper on the drawing board. Colors and water colors - They are coloring materials made of pigment, dyes, and others. they are used for coloring drawings.
- 12. Proper Care of Drafting and other Materials Be sure to inspect tools before using them. This is to check if they are in working condition. This can be detected when there is ease and speed when in use. After using a tool, clean it thoroughly with a damp cloth. Wipe it dry with another piece of cloth before keeping it. When not in use, the T-square is preferably hung by inserting the hole to a nail (attached to a wall) at the end of its blade. Do not abuse or misuse any piece of drawing instruments. Avoid throwing a tool to anybody; instead, hand it over to him carefully. Avoid setting off the distances individually by moving the scale to a new position from time to time, because slight errors in the measurements may accumulate and give rise to a large error.
- 13. Avoid unnecessary sliding of T-square or triangles protect the drawing. Pick up the triangle by its tip and tilt the T-square blade upward slightly before moving. Do not pull too much the steel tape of pull-push rule to the coil spring to avoid damage. Oil the movable parts of the measuring tools such as zigzag rules, calipers, dividers, and compasses to avoid stock-up. Report defective measuring tools and any hazard to instructor immediately. Gloves, masks and goggles are usually worn when cleaning tools since most cleaning agents and solutions are harmful to the body. Only use Cleaning agents as prescribed by the tool or equipment’s manufacturer. Cleaning the tools after use is highly recommended.