Generally, the accuracy level of ordinary lathe guide rail is only level 5, and the surface roughness is 0.8. Flatness and straightness are still relatively large compared to precision machine tools.

Taking ordinary machine tools as an example, the general accuracy range is: the processing length range is one meter, the rotation diameter is 400 mm of ordinary lathes, the roughness on the surface of the guide rail must reach more than 0.8, the straightness does not exceed 0.015mm, and the flatness does not exceed 0.012mm.

The longer the guide rails, the greater these tolerances.

Of course, the smaller these values are for the same type of machine, the higher the accuracy level represented, and the more difficult it is to achieve the accuracy that can be achieved.

On the earth, the country that produces the highest level of precision ordinary machine tools is not Germany, which has the best technology, nor the United States, which is the most powerful, but Switzerland, a small European country! Of course, the ordinary machine tool with the highest production accuracy level here does not refer to the highest technical level that the whole country can achieve, but the overall manufacturing level.

Whether the specific facts are like this or not, Yun Fei doesn't know the truth, anyway, the actual situation he once realized is like this.

Switzerland is only a small country in Europe, and its domestic industrial base is not perfect. But their domestic production of ordinary machine tools, in China, whose production capacity far exceeds his, is almost in short supply. The price of an ordinary Swiss lathe is three times that of the lathe with the highest precision level made in China!

Not to mention CNC machine tools.

Excluding those European and American countries are unwilling, Japan wants but does not dare to sell to China those most sophisticated high-end CNC machine tools, in China's high-end CNC machine tool market, the first choice of domestic users is also Swiss-made CNC machine tools. Swiss CNC machine tools, in terms of machining accuracy and stability, even surpass Germany! However, he does not have German production capacity, so there is no way to compare with Germany in terms of quantity.

Yun Fei once saw a precision ordinary lathe imported from Switzerland in the 80s, and when it was used for almost 20 years, it could even process parts with an accuracy of two or three μ!

Domestic ordinary lathes. Small ordinary lathes, conventional lathes with a rotary diameter of 250mm, 320mm/360mm, the maximum speed is only 2,000 revolutions, but the Swiss can reach more than 3,000 revolutions!

Anyone who does machining knows that the smaller the diameter of the part to be machined, the higher the linear speed required. This is because the smaller the diameter of the rotating body, the smaller the linear velocity when rotating. Even if it reaches 10,000 revolutions, the linear velocity of the center of rotation of the workpiece is zero. But the farther you are from the center point, the same diameter below. The higher the rotational speed, the higher the linear speed.

Although the highest speed that can be achieved on a domestic ordinary lathe is 2,000 rpm or 1,800 rpm, it cannot be used at all. Because that speed is only the design speed of the machine tool, if you really use this speed and process parts for a long time, it will not be long before all the gears in the entire headstock will be scrapped. But this is not the case with Swiss-grown products.

The reason why Yun Fei wants to establish a standard one or half higher than the level of domestic counterparts in the machine tools he produces is because the Swiss cutting machine tools have made him too impressed.

The smoother the machine guides. The smoother the cutting process during machining, the higher the quality of the product produced.

How can the accuracy level of a machine tool be reflected? It depends on the quality and accuracy of the parts processed by this machine! Machine users. But there is no professional testing equipment like machine tool manufacturers. Therefore, they test the accuracy of the machine tool, which is very simple, that is, directly install a part on the machine tool for a processing.

"Director Yun. You might as well not stare here, or go back to your office for a cup of tea or a newspaper. How about I'll call you when I'm waiting? Yang Bingbiao tried several times with the special file in his hand, but he couldn't find the feeling at all, and when he turned his head to see Guderian, he was not in the same state as when he first arrived in China and repaired the rails of those big equipment with him in the mountains.

"It's okay, you do yours, I'll watch from the side, it won't affect you." Yun Fei has always been curious about how the ninth-level fitters grind out the guide rails by hand, especially the detection methods of the ninth-level fitters.

It turned out that Yang Bingbiao was repairing and maintaining these equipment in a cave in the mountain, and when he overhauled the machine tools, he didn't have time to look at it at all. In the original world, the overhaul of machine tools and the grinding of guide rails were all done with guide rail grinders. He couldn't see it at all.

If the accuracy of the machine tool in their factory is greatly reduced, it will not be overhauled at all, but will be directly sold as scrap iron to second-hand equipment and buy new equipment. State-owned enterprises lack everything, that is, they are not short of money, and many of the state's annual financial allocations cannot be spent for a legitimate reason. Buying equipment is definitely a legitimate reason.

Yun Fei has always wanted to see the ninth-level fitter grinding guide rail in this era, and he knew that he would not wait for a few more years, and there would be almost no artificial grinding guide rail in China. The reason is that China's most elite mechanical workers have retired, and the newly grown technical workers have no opportunity to contact the most ultimate career of fitters, coupled with manual grinding guides, the efficiency is too low. If a person comes to grind the guide rail, a guide rail, it will take at least ten days and half a month!

"You're here, we won't work anymore......" Yang Bingbiao didn't care that he was the boss in front of him, and told the truth directly.

When Yang Bingbiao said this, Guderian also nodded on the side.

When Yun Fei, the boss, began to guard the previous process, and then the long roar of each machining process made the entire factory hear.

When grinding the guide rail, the energy can be highly concentrated, otherwise if you are not careful, the guide rail repaired with a file will be uneven. In the martial arts world, the master pays attention to the unity of a person's sword, and the ninth-level fitter grinds the guide rail, just like those super masters in the martial arts world, when fighting against others, they also have to be united with the sword, otherwise, they will not be able to reach their highest level and overturn the enemy.

Yun Fei's existence made Yang Bingbiao and Guderian unable to be quiet, because Yun Fei always kept asking all kinds of questions.

"Uh......" Yun Fei was speechless for Yang Bingbiao's words.

He understood the meaning of Yang Bingbiao's words.

Here he asked questions such as whether it was possible to achieve a guide rail with a second-level accuracy, and how to get more people to reach their level, which put pressure on the master craftsmen in the entire factory who could represent the highest level of Chinese and Soviet skilled workers.

It is too difficult to achieve an accuracy level of more than four levels.

The reason why Yun Fei is like this is that he wants to learn from Switzerland. Because the guide rails of Swiss precision machine tools are all repaired by workers with files and stones! The machine tool produced in this way has very little residual internal stress in the structure of the machine bed, and will not have an impact on the most important track of the machine bed with reasonable design. Some people are even bored to use mathematical models to analyze the machine tools produced in Switzerland, if they are not oxidized by the oxygen in the air, the guide rail of the machine tool will not produce more than 0.02mm deformation even for a hundred years.

"Brother Yunfei, what's wrong with you?" Ni Lishuang has now become a clerk in Yun Fei's office, and Yun Fei's assistant is still the fourth girl of the Mao family.

Ni Lishuang's main position is in finance, but she only graduated from a technical school, and she has no practical experience in finance at all, so she does some clerical work in Yunfei's office while studying with the finance department.

She is Yun Fei's housekeeper, and she must help Yun Fei manage her money so that her and Yun Fei's children will not starve in the future!

"What can he have? I want to go to the production workshop to see Master Yang, and they are grinding the guide rails...... "Mao Yadong made her feel very unhappy in her heart, and the sisters who grew up together since childhood poured out the reasons that made Yun Fei restless.

"What's so nice about grinding rails? It's just a few masters holding a file and scraping oil...... "Ni Lishuang is really a little puzzled by this."

Although she doesn't know how to do machining, but since she was a child, she watched her Yun Fei brother and them learn those things, and she didn't think that she could have much technical content if she didn't even use equipment.

And the classification will not tell them, maybe it won't be long before they don't see such a scene again.

I have experienced it in two lifetimes, and I have never been able to see that this can be achieved with just a few people and a few simple tools that far exceed the level of processing achieved by the most sophisticated advanced machine tools.

Yun Fei fidgeted for three days, and felt that he couldn't wait any longer in less than half an hour on the fourth day of work, and wanted to go to the scene to see, but he was worried that it would affect the work of the two, and he was about to take the two women in the office to the ball screw factory guarded by Wang Qingfeng to see the machining center that had just been transported, and he was told that the guide rail had been grinded.

Although he didn't see how the ninth-level fitter detected and processed the process, Yun Fei was also quite happy to see the results obtained in the processing process.

"You guys had an all-nighter last night?" Yun Fei walked to the scene and found that not only Yang Bingbiao and Guderian were here, but several other ninth-level fitters in the entire factory were here, and all of them had red eyes and a tired face.

"I know that you are anxious to see the finished product, all after completing the scraping, starting at six o'clock yesterday afternoon, I left the other brothers behind, and began to grind the surface of the machine with oil stone and sandpaper in turn, and now it has barely reached the third-level accuracy......" Yang Bingbiao replied to Yun Fei's words with a tired face.

"I'll go ......" Yun Fei secretly exhaled a long breath! (To be continued......)