When designing with CAD software, we often use the construction line function. Using the construction line function, we can create a construction line (ray) that extends indefinitely to one end or a construction line (reference line) that is infinitely extended to both ends, and can also create a circular construction line. Since the construction lines do not change the extension of the drawing, their size does not affect the zoom or viewport. We can move, rotate, and copy construction lines as we move, rotate, and copy other objects. We can also use construction lines as a reference for creating other objects. For example, we can use construction lines to find a center point for a hole, prepare multiple views for the same object, or create a temporary section that can be used for object snapping. Haochen CAD Machinery 2011 is one of the most widely used mechanical CAD software. In the following CAD tutorial, we will take Haochen CAD Machinery 2011 as an example to explain its specific operation method. First, find the construction line command in the menu of Haochen CAD Machinery 2011. After clicking, the software will pop up a dialog box (Figure 1). figure 1 When creating, we can type [HC_CONSTLINES] at the command prompt. Then in the [Construction Line] dialog box, freely select the construction line you need to use, and then specify the insertion point of the construction line to create. In order to facilitate everyone's understanding, let's take some common construction line creation steps as an example to demonstrate the method of creating construction lines in Haochen CAD Machinery 2011. First, create a construction line perpendicular to two points 1. At the command prompt, type [HC_CONSTLINES]. 2. In the [Construction Line] dialog box, select the third button in the second line. 3, specify the construction line, C-line (construction line) construction line must pass a point. 4. Specify a second point or enter an angle value to define the direction of the construction line. Second, create a construction line with an absolute angle 1. At the command prompt, type [HC_CONSTLINES]. 2. In the [Structure Line] dialog box, select the fourth button in the first line. 3, specify the construction line, C-line (construction line) construction line must pass a point. 4. Specify a second point or enter an angle value. Third, create concentric circles 1. At the command prompt, type [HC_CONSTLINES]. 2. In the [Structure Line] dialog box, select the third button on the third line. 3. Select a circular arc or a circle. 4. Specify the diameter value of the concentric circle. To draw multiple circles, type [|] (pipe symbol) between the diameter values. Fourth, create a circular construction line tangent to the line 1. At the command prompt, type [HC_CONSTLINES]. 2. In the [Construction Line] dialog box, select the fifth button on the third line. 3. Select a reference line, a ray or a line. 4. Specify a point to define the position of the circle. 5. Specify the radius value. 6. Enter to confirm. 5. Create a construction line at a certain distance from the selected line 1. At the command prompt, type [HC_CONSTLINES]. 2. In the [Construction Line] dialog box, select the first button in the second line. 3. Select a reference line, a ray or a line. 4. Specify an insertion point or enter a distance value. 5. If you entered a distance value in step 4, specify which side the construction line is offset from the baseline. Of course, in addition to this, there are many types of construction lines, but the drawing methods are similar, and you can select the specific method according to the drawing requirements. Interested friends can log in to Haochen CAD official website to download Haochen Association CAD Machinery 2011: http:// If you have any questions about Haochen CAD Machinery 2011 software, you can join Haochen CAD technology QQ group. Hourglass Sleeves,US Hourglass,Aluminium Ferrule Figure 8 Type Lisheng Trading Co., Ltd. , http://www.jnbuckles.com