The reason for the design is that it is too troublesome to find the size of the factory drawings. It is really fatal to find 80 corresponding size serial numbers out of 300 size serial numbers. A lot of time will be wasted in the process of finding them. Therefore, I have improved the retrieval efficiency of drawing serial numbers and tried to add my own design to the engineering drawings. In view of the problem that some factory drawings do not have color printers, the previous color works are improved. It is beneficial to popularize and reduce the cost of drawing printing, but also can play an excellent retrieval speed to improve the efficiency of the work.

Fig. 1 is a nine-square grid line that needs to be added. the whole engineering drawing is divided into nine small squares, and the sequence number interval that needs to be limited for drawing is set in each small square. In this way, we can quickly and effectively narrow the scope of search in no matter what the situation is, improve efficiency and make no difference.

The main purpose of fig. 2 is to express some regular details in my design, which can be understood by an ordinary person even without instructions.
Why do I use 100 as the starting point and the mantissa 99? I use the first number 1 of the 100 as the positioning number of the nine-square grid, so that I can quickly respond and find the position when looking at the drawings. At first, I tried the rules of 0~99,100-199 and 1~100,101~200, but the facts show that this thinking is easy to misunderstand. For example, in 100 1, many times we will unconsciously follow the first number to find it, so here I will make mistakes directly. Designing in the wrong way is more in line with people's habits, and there are effective ways to locate the number and reduce the thinking mistakes in the process. In addition, the reason why it is Jiugongge instead of 12 and 18 is that the first letter of a number corresponding to our mobile phone is only 0~9, and I have removed 0 for convenience, and the remaining 9 digits are just arranged as digital coordinates.

This is the final expression effect of the work. I simply arranged 180 serial numbers in the figure, but no matter how I arranged them, your search scope is within that small range. Of course, there is also a way to enhance the Jiugong grid, which is correctly 81, but the actual use is no different from Jiugong grid, with one more positioning size.

Fig. 4 is the general image of the enhanced version of the nine-nine palace grid. I did not add positioning numbers in the figure, because I would be exhausted because there were too many, so I mainly read the text explanation.
The enhanced version is more suitable for drawings with a measurement size serial number greater than 1000 when the drawings are extremely complicated. If the effect of Jiugongge is also very simple, it is nothing more than one more positioning number and the search time will be increased by a few seconds. Of course, if it is the ordinary Jiugongge with serial number in the 1000, it is enough. If it is used again, although the positioning speed will be greatly improved, the preparation time of design drawings will be greatly increased. So for the sake of cost performance, I did not take the enhanced version as the main design.