Develop good CAD drawing **habits to improve drawing efficiency!

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Developing good CAD drawing habits is particularly important for those who are new to CAD. Below are some points that must be taken into consideration when drawing. 1. Understand common issues: (1) When drawing the same diagram, some people draw it at an appropriate size, while others draw it so small that it’s barely visible. Why is this? This is because the operation to set the boundaries of the drawing area was not performed, or although the LIMITS command was used to set them, it was forgotten to use the ALL option in the ZOOM command to reconfigure the drawing area. The setting of the drawing area is determined based on actual drawing requirements. (2) Someone used a line style with the name “HIDDEN” to draw line segments, but found that the resulting lines appeared as solid lines. What causes this? This is caused by an inappropriate \"linear scale\"; in other words, the \"linear scale\" may be too large or too small. The solution is to open the Linear Manager dialog box and adjust its “Global Scale Factor” to an appropriate value. (3) After dimensioning, it sometimes happens that the dimension text cannot be seen. What causes this? This is because the overall scale factor for dimensioning has been set too low; open the Dimensioning Style dialog box and increase its value. It is very necessary for beginners to fully understand these issues, as it helps improve the quality and efficiency of drawing. 2. Comparison is necessary for differentiation; for commands that are easy to confuse, one must make an effort to understand the differences between them. Such as ZOOM and SCALE, PAN and MOVE, DIVIDE and MEASURE, and so on. 3. The hierarchy should be clear. Layers are like transparent overlays, which can be used to organize different types of graphic information effectively. During the learning process, some people, in order to save time, simply select properties such as color, line type, and line width from the dropdown lists on the object properties toolbar. This is not good, as it makes it more difficult to work with the information contained in the graphics; it’s important to pay special attention to correcting this bad habit. Ensure strict clarity in hierarchy and standardized drawing. My experience is that developing good *habits brings tremendous benefits. 4. The line thickness must be clear; the ability to display the line width of solids is a new feature in AutoCAD 2000. By using line widths, it is possible to clearly show the cross-section of components, the depth of elevations, dimension lines, and the thickness of different objects, using both thick and thin lines. As a beginner, you must specify the line width and display it through layers. Improve the quality of one’s drawings and the level of presentation. 5. Differentiate between internal and external elements: Utilizing AutoCAD 2000’s “blocks” and attribute functions can **improve drawing efficiency**. “\"Blocks\" are divided into internal blocks and external blocks. An internal block is a block defined within a file, and it can be used freely within that file. Once defined, an internal block is stored and opened along with the file. External blocks write the main file of the \"block\" to disk, and other graphic files can also use it; it is important to note that this is a key difference between external and internal blocks. 6. Airtight coverage: When filling patterns, it is important to ensure that the entities forming the boundaries of the shaded areas intersect at their endpoints; in other words, the areas must be closed off to achieve an airtight coverage” ； Otherwise, incorrect filling will occur. During the drawing process, it’s best for us to also learn how to identify “flaws” and fix errors. 7. Text should be written in a standardized manner. Text is an essential part of engineering drawings, including dimension labels, drawing descriptions, annotations, titles, etc. Together with graphics, text conveys the complete design concept. Although AutoCAD offers strong text processing capabilities, text that meets engineering drawing standards is not provided directly. Therefore, one must learn to set the standard font “Chang Fangsongti”. The brief steps for carrying out this operation are as follows: open the “Text Style” dialog box, create a new style which can be named “Chang Fangsongti”; in the dialog box, change the font name to “Fangsongti GB-2312”, and also set the width ratio to 0.67. The text for dimension labels can be changed to “italic.shx” instead of “FangSong GB-2312”. Another simpler way to format text according to specific rules is to use the “Engineering Text” style provided in the AutoCAD template files ； Note: Before use, start AutoCAD by using the \"Use Template\" option, select a national standard title (such as GBA3) to enter drawing mode. Then set the “Engineering” style as the current working style. This method is not mentioned in most books, so we should pay attention to doing more examples in this area. 8. Special characters require special handling. In actual drawing, it is often necessary to enter certain special characters, such as angle markers and diameter symbols. These can be entered using the control codes provided by AutoCAD, making them easier to master. Entering other special characters, such as the Greek letters “τ”, “α”, “δ”, and so on, is not so easy to master. It requires using the “Other…” option of the MTEXT command to copy Greek letters from special fonts and then paste them into the drawing area. Special attention should be paid to edits such as font conversion. There are also some special texts; for example, “φ” is widely used in mechanical drawing and refers to dimension tolerances with upper and lower deviations, which can also be achieved using the \"stacking\" function of the MTEXT command. This is far more convenient than adjusting the corresponding values in the dimensioning dialog box. My personal experience is: it’s extremely convenient! 9. Nothing can be accomplished without following rules and standards. Engineering drawings serve as an important basis for part manufacturing, project construction, and component assembly. At any time, in an engineering drawing, technical annotations are an essential and important part. In some cases, engineering annotations are even more important than the drawings. Many of my friends are not afraid of drawing, but they are afraid of labeling ； One of the reasons is that there are too many options in the dimensioning method dialog box; it’s difficult to understand them, and it’s even harder to know how these options work together, which often makes it hard to achieve the desired dimensioning results. To this end, in addition to understanding the meaning and common values of the various options in the dialog boxes, one should also make sure to follow these five rules when drawing: (1) Create a separate layer for dimension labels, so as to keep them apart from other information in the drawing and to facilitate various operations. 　　(2) Create a dedicated text style (such as the aforementioned “Long SimSun”) and size for dimension text. 　　(3) Set the size unit to the desired measurement unit, and set the precision to the desired minimum unit. 　　(4) Use the Size Method dialog box to set the overall scale factor as the scale factor when drawing the graphic. 　　(5) Make full use of the target capture method to quickly select search points. 　　(10) Two spaces, two functions: In the AutoCAD environment, there are two types of spaces: model space and paper space, each with different functions. Generally speaking, model space is a three-dimensional space used primarily for designing the geometric shapes of parts and graphics; designers usually develop their main design concepts in model space ； Drawing space is used to represent geometric models on engineering drawings, and is specifically intended for generating drawings ； Paper space, sometimes also referred to as “layout,” is a paper space environment that simulates a paper page and provides intuitive printing settings. The current design direction is to move towards 3D part modeling and design. Once a part has been designed, it needs to be represented in the form of engineering drawings, which requires projecting it from various angles, marking dimensions, adding title bars and drawing frames, etc. These operations are not easy to carry out in model space, but they are quite straightforward in sheet space. Viewport objects can be created and placed in paper space, as well as title bars or other geometric shapes can be added. Multiple layouts can be created in the drawing to display different views, with each layout allowing for different printing scales and sheet sizes. The graphics displayed in the layout are exactly the same as those printed on the drawing sheet. 　　 11. Returning to the basics: The goal of computer-aided drawing is to enable the design results to be put into use in practical production. Currently, the design results are primarily fed into production in the form of paper-based drawings, and at design firms, paper-based drawings also constitute the main focus of drawing archive management. Although the development trend of computer-aided design is to achieve paperless design and production, with very few large manufacturing enterprises as exceptions, the vast majority of ordinary design and production units still rely on paper-based drawings as the basis for organizing their design and production processes. Therefore, how to convert the electronic format drawings produced by AutoCAD into paper-based drawings on specified paper sizes is an issue that is closely tied to actual production processes; in a sense, this step is just as important as graphic modification, editing, and other drawing tasks. In summary, only by learning can one realize one’s shortcomings. AutoCAD also has many useful features, especially some 3D functions. Learning is endless; as long as everyone is good at summarizing and generalizing in the process of learning, they will surely be able to find the best methods for learning.