Introduction to Engineering Drawing

What is Engineering Drawing ?

It is a language for transferring the details of an object to the labor who works in the manufacturing field.

When a multi-storied building is constructed, the primary need of the labors is Engineering Drawing. All details like dimensions, door-window details, floor-roof details, false-ceiling details if any and staircase dimensions, etc, are reflected in the Engineering Drawing. The labors may not know the reason behind the design parameters of the staircase, but they surely know how to read the Engineering Drawing and how to start erection works accordingly.

Therefore, It is a language by which engineers and labor communicate with each other for construction works.

Instruments:

The following instruments are used to prepare drawings easily and accurately:

  1. Drawing Board
  2. T-square
  3. Set Squares-45 degree and 30 degree -60 degree
  4. Compass
  5. Divider
  6. Scales
  7. Protector
  8. French Curves or flexible curves
  9. Drawing Sheets
  10. Pencils
  11. Eraser
  12. Drawing board clips
  13. Duster made of cotton
  14. Drafting machine

Size of Drawing Sheets:(mmxmm) 

  • A0: 841 X 1189
  • A1: 594 X 841
  • A2: 420 X 594
  • A3: 297 X 420
  • A4: 210 X 297
  • A5: 148 X 210

Purpose of some new instruments:

T-square: used for drawing the horizontal lines, vertical lines.

Set-square: In combination with T-square, set squares are used to draw the lines at 30 deg or 60 deg angle and 45 deg angle with vertical or horizontal lines. Also used for drawing perpendicular lines and parallel lines.

Drafting Machine: the tasks performed by T-square and Set Square, all these tasks can be performed by only using drafter. 

French Curves or flexible curves: These are used for joining the points on the curves while creating the geometrical curves.

Basic things you should know:

1. Dimension Systems:

Under this section, you will come to know how to put dimensions in an Engineering Drawing.

2. Scales:

you will learn how to scale the object for accommodating the object in the drawing sheet.

3. Construction of Geometrical Curves:

In this section, how to draw the basic geometrical shapes e.g polygon, parabola, ellipse, etc will be taught to you.

4. Projection of Points and Lines:

Here, you will learn about the different types of projection- first angle projection, second angle projection, third angle projection, fourth angle projection. If a point or a line is situated in the first quadrant, how to draw the projections of those points in a drawing sheet has been explained under this section.

5. Projection of Solids:

Here how to draw the different views of a 3-d solid object has been discussed.

6. Projection of Sections of Solids:

If the object is cut at a particular height and a particular angle, the different views of the cut object has been explained here.

7. Isometric Projection:

Differences between the orthographic projection and isometric projection have been discussed here. You will learn how to draw the isometric projection of an object.

8. Development of Surfaces:

If all the surfaces of an object are developed or opened, how will it look has been taught here.

Thank you for reading. Let us make a beautiful world together. God bless.

Introduction to "Workshop/Manufacturing Practices"

Workshop: It is the shop (or place) where some physical useful work has been performed for manufacturing different types of products. To execute this work, different types of shops are required which are explained here.

For different types of manufacturing processes, different types of shops are required :

Fitting Shop: In this shop, different parts of a product are assembled to get the final shape of the product. The following operations are performed on the parts of the job before assembling: filing, drilling, tapping, cutting, etc. Surface finishing is maintained by Filing operation. If we require to make a hole in the parts of the job, we have to perform drilling operations. Making internal threading is called Tapping. For getting the required shape to the job piece, if it requires to remove some parts of the job piece, we have to go for cutting operation. With the help of, ‘Hack-saw” this operation is performed. Carpentry shop is also used for making furniture. Timber is the material used in the carpentry shop.

Casting shop: There are some design setups where we can make the mold with the help of a pattern. The pattern must look like the final product. So, the pattern is the replica of the final product. Mold is a cavity within which hot molten metal is poured. This mold is prepared with the help of a pattern. So, the shape of the mold is also the same as the shape of the final product. When the mold is filled up with the hot liquid molten metal, it is kept for few hours for cooling. After a few hours, the molten metal inside the mold becomes solid. This solid takes the shape of the mold. Then, this solid metal is separated from the mold and thus we get our required final product.

Casting

Forming Shop: Sheet metal works are performed in this shop. If we want to manufacture products of different shape of sheet metal, deformation of sheet metal with the help of Die and Punch is performed by applying pressure to get the shape of the final product. This process is called Forming process.

Forming

Machining shop: In this shop, machining operations are performed. Machine tools and cutting tools are used to manufacture the products. There are two types of machining processes – conventional machining and non-conventional machining process. In conventional machining, we use Lathe machine, Shaping Machine, Milling Machine, Drilling Machine, etc, whereas, in non-conventional machining, we use an electron beam melting process (EBM), Laser beam machining(LBM), computer numerical controlled (CNC), etc. In a conventional machining process, the size of chips is large and tool life is less compared to the non-conventional machining process. Also in the conventional machining process, direct contact exists between the workpiece and cutting tool. 

Lathe Machine

Welding shop: It is a joining process by which two metals are joined together by applying heat or pressure. In some joining processes, heat plays an important role and in some joining processes pressure plays an important role. In some welding processes, base metal and electrode both melt. The filler material may also be added to the joint to form a pool of molten metal which is known as Weld Pool. Two metals can be joined by Soldering and Brazing also, but in these cases, low temperature is involved and base metal does not melt. So, the use of filler material is compulsory in Soldering and Brazing processes.

Pics :collected from “shutterstock.com”.
Thank you for reading. Let us make a beautiful world together. God bless.