A note that is called out in specific spots in the field of the drawing. It is numbered with a stylized flag symbol surrounding the number.
This is especially true for the engineer. The purpose of this guide is to give you the basics of engineering sketching and drawing. We will treat "sketching" and "drawing" as one.
This is just an introduction. Figure 1 - A Machined Block Isometric Drawing The representation of the object in figure 2 is called an isometric drawing. This is one of a family of three-dimensional views called pictorial drawings. When drawn under these guidelines, the lines parallel to these three axes are at their true scale lengths.
Lines that are not parallel to these axes will not be of their true length. Figure 2 - An Isometric Drawing Any engineering drawing should show Engr drawing If the isometric drawing can show all details and all dimensions on one drawing, it is ideal.
One can pack a great deal of information into an isometric drawing.
However, if the object in figure 2 had a hole on the back side, it would not be visible using a single isometric drawing.
In order to get a more complete view of the object, an orthographic projection may be used. Orthographic or Multiview Drawing Imagine that you have an object suspended by transparent threads inside a glass box, as in figure 3. Figure 3 - The block suspended in a glass box Then draw the object on each of three faces as seen from that direction.
Unfold the box figure 4 and you have the three views. We call this an "orthographic" or "multiview" drawing. Figure 4 - The creation of an orthographic multiview drawing Figure 5 shows how the three views appear on a piece of paper after unfolding the box.
Figure 5 - A multiview drawing and its explanation Which views should one choose for a multiview drawing? The views that reveal every detail about the object.
Three views are not always necessary; we need only as many views as are required to describe the object fully. For example, some objects need only two views, while others need four. The circular object in figure 6 requires only two views.
Figure 6 - An object needing only two orthogonal views Figure 7 - An isometric view with dimensions We have "dimensioned" the object in the isometric drawing in figure 7.
As a general guideline to dimensioning, try to think that you would make an object and dimension it in the most useful way.
Put in exactly as many dimensions as are necessary for the craftsperson to make it -no more, no less. Do not put in redundant dimensions. Not only will these clutter the drawing, but if "tolerances" or accuracy levels have been included, the redundant dimensions often lead to conflicts when the tolerance allowances can be added in different ways.
Repeatedly measuring from one point to another will lead to inaccuracies. It is often better to measure from one end to various points.
This gives the dimensions a reference standard. It is helpful to choose the placement of the dimension in the order in which a machinist would create the part. This convention may take some experience. Sectioning There are many times when the interior details of an object cannot be seen from the outside figure 8.
Figure 8 - An isometric drawing that does not show all details We can get around this by pretending to cut the object on a plane and showing the "sectional view". The sectional view is applicable to objects like engine blocks, where the interior details are intricate and would be very difficult to understand through the use of "hidden" lines hidden lines are, by convention, dotted on an orthographic or isometric drawing.Dec 17, · Mechanical drawing is a super handy skill for discussing the shape of physical objects.
This video covers 2D projection, multi view drawing, linear .
1 Drawing an Approximate Representation of an Involute Spur Gear Tooth Project Description Create a solid model and a working drawing of the . An engineering drawing is a type of technical drawing used to define the requirements for engineering products/components. The purpose of an engineering drawing is to clearly and accurately capture all geometric features of a product/component so that a manufacturer or engineer can produce the .
Engineering Drawing with Worked Examples has 14 ratings and 1 review: Published by Hutchinson, pages, Hardcover/5. This section provides a tutorial on engineering drawing and sketching. Engineering Drawing with Worked Examples has 14 ratings and 1 review: Published by Hutchinson, pages, Hardcover/5.