Sharing of CAD drawing skills
(1) Draw the same picture. Some students draw the same picture in a moderate size, while others draw it so small that they can't even see it. Why?
This is because the boundary setting operation of the drawing area has not been completed, or even though it was set by using the LIMITS command, I forgot to rearrange the drawing area by using the ALL option in the ZOOM command. The setting of drawing area is based on the actual drawing needs.
(2) Some students draw a line segment with the name "hidden", but they find that the drawn line segment looks like a solid line. What is the reason?
This is caused by improper "linear scale", that is to say, the "linear scale" is too large or too small. The solution to the problem is to open the dialog box of the production line manager and modify its "global scale factor" to an appropriate value.
(3) After dimensioning, it is sometimes found that the dimensioning text cannot be seen. What is the reason?
This is because the overall scale factor of the dimension is set too small. Just open the dialog box of dimensioning method and change its value to be larger.
The above three problems are just the three most typical problems and difficulties my classmates encountered in the process of getting on the computer. There are countless practical problems. As a student, it is necessary to know these problems deeply, which is very helpful to improve the quality and efficiency of drawing.
2, there is comparison and identification.
Easy to confuse orders, pay attention to let yourself understand the difference between the two. Such as scale, translation and movement, segmentation and measurement.
3, the level should be clear.
Layers, like transparent overlays, can be used to organize different types of graphic information well. In the learning process, in order to save trouble, students directly select entity information such as color, line type and line width from the drop-down list box in the object property toolbar, which is very bad and makes the information processing in graphics not so easy. We should pay special attention to correcting this bad habit of ours. Strictly stratified and standardized drawing. My experience is: form good habits and benefit a lot.
4, the thickness should be clear
Being able to display the line width of entities is a new function of AutoCAD2000. Using line width, you can clearly display the cross section of components, the depth of elevation, the dimension line and the thickness of different objects with thick lines and thin lines. As a student, you must specify the line width across the layer and display the line width. Improve your drawing quality and expression level.
5. There are differences between inside and outside
Using the "block" and attribute functions of AutoCAD2000 can greatly improve the drawing efficiency. "Blocks" can be divided into internal blocks and external blocks.
An internal block is a block defined in a file and can move freely inside the file. Once the internal block is defined, it will be stored and opened at the same time as the file.
The external block writes the main file of the "block" to disk, and other graphics files can also use it. Please note that this is an important difference between external tiles and internal tiles.
6. It is waterproof.
Special attention should be paid to the fact that the entities that form the boundary of the shadow area must intersect at their endpoints, that is, they should be closed and "watertight"; Otherwise, wrong padding will occur. As a student, it is best to learn how to find "loopholes" and fix mistakes.
7. Writing should be standardized
Text is an indispensable part of engineering drawings, such as dimensioning text, drawing description, notes, titles, etc. Words and graphics together express a complete design idea. Although AutoCAD2000 provides powerful word processing functions, it does not directly provide words that meet the engineering drawing specifications. Therefore, we should learn to establish a standard text of "long imitation of Song Dynasty". The concrete steps are as follows: open the dialog box of "Text Style", create a new style, which can be named "Long Imitation Song Style", change the font name in the dialog box to "Imitation Song Style GB-23 12", and change the width ratio to 0.67. The text of the dimension can be "italic.shx" instead of "imitation song GB-23 12".
Another simpler way to use standard text is to directly use the "engineering word" style provided by AutoCAD2000 template file; Note that AutoCAD2000 should be started by "using templates" before use, and the national standard title (such as GBA3) should be selected to enter the drawing state. Then set the "Project Word" style as the current working style. This method is not mentioned in most textbooks, so students should pay attention to supplement this kind of training.
8, special people, special treatment
In actual drawing, it is often necessary to input some special characters, such as angle symbols and diameter symbols. These are all input with the control code provided by AutoCAD, which is relatively easy to master.
Other special characters, such as "τ", "α", "δ" and other Greek letters, are not so easy to master. It needs to use the "Other" option of the MTEXT command to copy Greek letters in a special font and then paste them into the writing area. Pay special attention to editing such as font conversion.
There are also some special characters, such as "φ", which are widely used in mechanical drawing, called dimensional tolerance marking of up-and-down deviation, and can also be realized by the "stacking" function of MTEXT command. This is much more convenient than adjusting the corresponding function values in the annotation dialog box. My personal experience is: especially convenient!
9. If you don't follow the rules, you are not Fiona Fang.
Engineering marking is an important basis for parts manufacturing, engineering construction and parts assembly. Engineering notes are an indispensable part of engineering drawings at any time. In some cases, engineering annotation is even more important than graphics.
Many of my classmates are afraid of painting and labeling; One of the reasons is that there are too many dialog box options for labeling methods, which I can't see clearly and I don't know how to cooperate, so it is often difficult to achieve the ideal labeling effect.
To this end, in addition to understanding the meaning and common values of the options in the dialog box, you should also urge yourself to follow the following five rules when learning:
1. Create an independent layer for dimensioning, so that it can be separated from other information in the drawing and convenient for various operations.
2. Establish a special text style (such as the aforementioned "Long Imitation Song Style") and size for the size text.
3. Set the dimension unit to the required measurement unit, and set the accuracy to the minimum required unit.
4. Use the Size Mode dialog box to set the overall scale factor as the scale factor when drawing a graph.
5. Make full use of the target capture mode to quickly pick up the search points.
10, two spaces, two functions, two exercises
There are two kinds of spaces in AutoCAD2000 environment: model space and drawing space, and their functions are different. Generally speaking, the model space is a three-dimensional space, which is mainly used to design the geometry and graphics of parts. Designers usually complete their main design ideas in the model space. The drawing space is used to express the geometric model on the engineering drawing and is specially used for drawing. Paper space, sometimes called "layout", is a paper space environment, which simulates paper pages and provides intuitive printing settings. At present, the design direction is to enter the modeling and design of three-dimensional parts, so when the parts need to be expressed on the designed engineering drawings, they need to be projected from all angles, dimensioned, and added with title bars and drawing frames. At this time, it is inconvenient to do these operations in model space, but it is convenient in drawing space. You can create viewport objects and place them in paper space, and you can add title blocks or other geometry. You can create multiple layouts in a drawing to display different views, and each layout can contain different print scales and paper sizes. The graphics displayed in the layout are exactly the same as those printed on the drawing page.
1 1, 99 is one
The goal of computer drawing is to make the design results play a role in production practice. At present, the design results basically enter production in the form of paper drawings. At the same time, in the design unit, paper drawings are also the main object of drawing file management. Although the development direction of computer-aided design is to realize paperless design and production, except for a few giant manufacturing enterprises, most ordinary design and production units still take paper drawings as the basis for organizing design and production. Therefore, how to convert the electronic format drawings designed and generated by AutoCAD2000 into paper format drawings with specified format is a problem closely related to production practice. In a sense, this step is as important as the drawing process such as graphic modification and editing.
Therefore, in the study of "printing", in addition to understanding the use of dialog boxes, we should also actively participate in a demonstration class organized by teachers, so that we can truly feel the last link of "computer drawing".
The above is about "sharing CAD drawing skills". I hope this tutorial is useful to you. Please try it with the tutorial. Click this link to learn more about CAD tutorials: