Course Content
AutoCAD for beginners
About Lesson

In this lesson I will show you what a typical mechanical project looks like. As you can see, this drawing is missing the front view, so I will do my best to complete it.

Before I get into something more specific, I’ll include a few helper functions. This is primarily about Object Snap, so I’ll click on this arrow and choose the following options from the menu: Endpoint, Midpoint, Center, Quadrant, Intersection and Perpendicular. In addition, I will also need the Object Snap Tracking function, so I will click on this icon and then activate the Ortho mode and check if the Dynamic Input function is active. Having set all the necessary parameters in this way, I can start the Line command and draw a basic outline with a few strokes. To keep the dimensions correct, I will first place the cursor on the left edge of the top element and wait for AutoCAD to automatically take its position. If I repeat the same process for the element on the right, it will not be difficult for me to determine the position of the first point and place a new line. Its end point should coincide with the position of the bottom edge, so I will take this information in one stroke and finish drawing the first element. Now I can continue and in the same way determine the length of the lower segment and immediately after that the one on the right. In the end, I just need to click on the point from which I started and thus complete the drawing of this contour.

I just noticed that there is a small addition on the right element, so I will try to transfer it to the center part of the drawing as well. For that I need a new line, so I’m going to click on this icon and use Object Snap Tracking to determine the position of the starting point. Its end coincides with the existing elements, so it will not be difficult for me to click on this corner and thus finish drawing the new line. Apparently this part runs the whole length, which means I need another line on the other side. This time I will use the Copy command, select the existing element and place it in the appropriate position. After that I can add a line that will connect these two points and thus complete the bottom edge of this element.

According to what is shown on both projections, it can be concluded that there is one protruding part in this zone. In order to faithfully transfer it to the third segment, I will draw a vertical line from this point and immediately remove the excess part with the help of the Trim command. At this magnification, I noticed that these two lines are not connected at all, so I will do my best to correct that. To that end, I will use the command Fillet its shortcut by pressing F and Enter, and since the Radius parameter is already set to zero, I can immediately select both elements and complete this operation.

Since I drew only one half of this element in this way, I can use the Copy command, select these two lines and determine their new position by selecting characteristic points.

The next detail relates to the length of this protruding part. That’s data that can easily be passed from the right, so I’ll run the Line command and with a little help from Object Snap Tracking determine the exact position of the new line. After that I just need to remove the redundant segments and this can be achieved by using the Trim command. If I press Enter and declare all existing elements as potential edges, it will not be difficult for me to shorten these vertical lines with three clicks.

Based on the available data, it is easy to conclude that something is wrong in this zone. In other words, I’m sure these two edges need to be significantly shorter, so I’ll run the Fillet command again and select the appropriate elements to correct this error. In the same way, I can also shorten the line representing the left edge because it should not cross this border either.

If you pay attention to the broken line extending around the projecting part, you will easily come to the conclusion that it represents a welded edge, and this is confirmed by the detail that can be seen in the side projection. The same curvature should appear in this zone, and I will use the Mirror command to draw it. This means choosing the appropriate icon and selecting the element on the right. If I then click on the point in the middle and specify the position of the bisector, a new element should appear on the left. Since I did all this without any preparation, this part didn’t fit very well, but that can be fixed very easily. It is enough to press the M and Enter keys and thus launch the Move command, select this curve and place it in the appropriate position with two clicks.

The next problem I have to solve concerns the position of this circle. It represents a hole in the horizontal plate, which means that two lines should appear there. So I will first run the Line command and use the Object Snap Tracking function to determine the position of the starting point. The length of the line is not important at this point, so I’ll settle for a slightly shorter element. If I repeat the same procedure for the other side of this circle, I will have enough data for the second phase, ie. drawing sets of holes. Fortunately, there is already an element on the right that fully suits my needs. That’s why I’m going to start the Copy piece and select everything in this zone with one move. If I then select this end as a reference point and transfer all the selected elements to the left side, you will see that they fit perfectly into the space provided for it. This means that I don’t need these two lines anymore, so I will remove them from the drawing.

The circular arc on the left edge should basically appear as a straight line, so I’ll apply the appropriate function and draw a new element with a few strokes. The same curvature exists on the other side, so I will copy this line and thus complete this detail as well.

The hole represented by this circle can basically be represented by two lines, so I’ll use the Line command again and draw two new segments in a moment. Since this is a hidden element, it should be displayed with a different line type. To achieve this, I will simply select these two lines and from the Properties section select the Hidden option. If I press Esc after that, you’ll see that both lines have become dashed. From the above view, it can be concluded that this hole goes through the entire element, which means that these two lines must also appear on the other side. The easiest way to do this is by copying, so I’ll run the appropriate command and add two new elements in one go.

The position of the second opening is also clearly shown. There is a high probability that it matches the size of this circle, but it wouldn’t hurt to check it. So I’m going to run the Copy command and select the point that’s on the left quadrant. If I then turn off orthogonal mode and move the cursor to this point, it won’t be difficult for me to hit the middle of this line and precisely position the new element. As you can see, it fit perfectly, so I can move it to its rightful location. To that end, I’ll run the Move command and again use the Object Snap Tracking feature for precise positioning. This element must also appear in the side projection, so I will use these two lines and copy them to the right side. Unfortunately, they came out a little shorter than they should, so I have to make them longer. The Extend command is usually used for this, and I will deliberately use the Trim function instead because I want to remind you that the same result can be achieved with the help of the Shift key.

Before I finish this lesson, I just need to check what I have accomplished. It seems to me that there is another opening here, although it does not appear in the upper segment. Regardless, I’m going to copy this circle and choose the bottom quadrant as a reference point. If I then use the Object Snap Tracking feature, there should be no problem determining its final position.

This change requires some intervention in the upper segment as well. Fortunately, all of this can be solved by copying, so I’m going to select these two lines and move them to the top border. It looks like the space between these two elements is a bit bigger so I have to use the Extend command as well. That is why I will first click on the icon of the same name, select all elements with Enter and finally extend these two segments.

Everything seems to be in place now, except that I could work on this detail a bit more. For everything to be as it should be, the circular arc and the vertical line must meet at the same point. Therefore, by pressing the F key and Enter, I will start the Fillet command, and since the Radius parameter is already set to zero, I can select both elements and thus remove the redundant segment.

I hope that this example will serve as a good practice for you and that you will soon be able to create similar drawings yourself.

Join the conversation
0% Complete