Usage of 18-minute head

  Lin Zhenhua said goodbye to Ku Hongyang and returned to the metal workshop. At this time, the end of work hours had passed, the roar of machines in the workshop had stopped, workers had gone home, and the entire workshop was empty.

  Lin Zhenhua walked into the rest room of the moving class, took his clothes, locked the door and was about to leave, when he suddenly caught a glimpse of a frail figure standing beside an X62W universal milling machine, busily doing something.

  "Yang Xin." Lin Zhenhua walked over and shouted, suddenly remembering that Yang Xin had mentioned teaching him techniques a few days ago. Now all the workers in the workshop had gone home, but Yang Xin was still in the workshop, could it be that she was waiting to teach him techniques? Lin Zhenhua felt a wave of shame, he had been muddled and confused every day, only thinking about making money, and it was really unfair to this innocent and lovely little girl.

  "Little Hua... " Yang Xin turned around, with a hint of melancholy in her eyes.

  "Hey, you're waiting for me, right? I'm really sorry, these past few days... uh, I haven't been feeling too well, so as soon as I got off work, I rushed back home. Didn't expect you'd still be waiting for me." Lin Zhenhua, relying on his thick skin, stuttered out a pack of lies.

  Yang Xin replied weakly: "Oh, I didn't wait for you either. When I saw you leave, I left too. I thought maybe you had something to do."

  "Alright, I'm free today, otherwise, Master Yang can teach me now. What's the use of this mysterious machine in front of you?" Lin Zhenhua pointed at the milling machine and asked Yang Xin, with a hint of confusion in his eyes that made people wonder if he had just been hit by a car.

  Yang Xin of course knew that Lin Zhenhua was pretending to be silly. Even if he didn't understand the technology, after staying in the metalworking workshop for more than a week, he could still tell the difference between a lathe and a milling machine. However, today Yang Xin seemed to have something on her mind, and Lin Zhenhua's joke did not make her relax. She only replied with difficulty: "Little Hua brother, it's a bit unlucky today. My master asked me to finish these six gears, I'm afraid I won't have time to teach you."

  "Oh, that's great." Lin Zhenhua felt relieved, but as soon as the words left his mouth, he knew he had misspoken. He hastily added, "I mean, I'm also free, so you go ahead and take care of your business, I'll stay here with you."

  "Little Hua, you'd better go back first, I...I may be here for a long time to finish this." Yang Xin said with a red face.

  Lin Zhenhua scratched his head: "Won't be, right? It's just six gears?" He took the blueprint that Yang Xin had placed aside and looked at it, saying: "These six gears are ordinary gears, can be done in no time."

  "What's 'get it done in no time'?" Yang Xin was very skeptical about whether Lin Zhenhua was speaking Chinese or not, she focused all her attention on Lin Zhenhua's grammar, and for a moment, she didn't even notice that Lin Zhenhua could actually understand the blueprint.

  "Uh, this is Yunnan dialect, it means it can be completed very quickly."

  "But... but..." Yang Xin said two "buts", and then couldn't continue, her tears rolling around in her eyes a few times before falling down pitter-patter.

  "Don't cry, don't cry, Yang Xin, what's going on? Why are you crying?"

  "My master also said it was simple, but she explained it to me twice and I still didn't understand. She told me to adjust this dial, but I didn't understand how to adjust it." Yang Xin began to sob.

  "It's not a big deal if I didn't understand, is it?" Lin Zhenhua felt wronged. "If you didn't understand, you can ask again, and besides, since you don't understand, how could she leave you to do it alone? Where did she go?"

  Yang Xin said that the dividing head is an accessory on the milling machine. When milling gear teeth, workers need to rotate the dividing head to ensure that the milled gear teeth are evenly distributed. The number of turns of the dividing head varies depending on the number of teeth on the gear, which involves some calculation problems. This calculation itself does not require complex mathematical knowledge, at most it is just fraction and division knowledge, but some workers have low cultural level and poor mathematical thinking, so they think that using the dividing head is still quite troublesome. Yang Xin has a junior high school graduate's cultural level, but she is not one of those students with good math grades. Her master Jiang Tie Mei has an even lower cultural level, and her use of the dividing head is limited to having experience, unable to explain clearly, so it is reasonable that Yang Xin does not understand.

  "Master said I'm stupid, said I didn't pay attention, then she told me that if I don't finish these six gears, I shouldn't go home. If I don't do it, she'll go to the director tomorrow and say she won't take me...” Yang Xin said this, almost bursting into loud tears, but was afraid of being heard by people outside the workshop.

  "This extermination master!" Lin Zhenhua cursed.

  Yang Xin also didn't know what "Mie Jue Shi Tai" was, but from Lin Zhenhua's tone, it seemed to be some kind of female witch from Yunnan or something. Anyway, not a good person. She took out her handkerchief and wiped away her tears, saying to Lin Zhenhua: "Little Hua brother, you go back first, I'll think about it myself. If I still can't do it today, I'll just stay in the workshop overnight."

  "No need, no need," Lin Zhenhua said. "If you have difficulties, find Xiao Hua. It's just a degree head, I can teach you."

  "Are you kidding me?!" Yang Xin's eyes widened bigger than the vernier caliper, she would rather believe that Lin Zhenhua could pinch this all-steel vernier caliper into a steel ingot with his bare hands than believe he could set it to the correct position.

  Helpless, Lin Zhenhua repeated the nonsense of that dual-use military talent again. In fact, at that time, this concept had not been proposed by anyone yet.

  "Have you really operated a milling machine?" Yang Xin finally changed from complete disbelief to half-belief and half-doubt.

  "Give me some space." Lin Zhenhua roughly pushed Yang Xin aside, his hand brushing against Yang Xin's arm, causing Yang Xin's face to flush red as she hastily made way.

  Lin Zhenhua stood in front of the milling machine, silent for a moment, letting memories from later generations return to his mind. Then he began operating it. He shook the handle, skillfully clamping the workpiece onto the fixture. Next, he glanced at the blueprint and selected a scale on the dividing head's dial plate without hesitation, turning it smoothly. After positioning the workpiece correctly, Lin Zhenhua started the milling machine, and the cutter emitted a cheerful whirring sound, cutting out strip after strip of shiny black iron filings from the workpiece.

  "My goodness, you're even more skilled than my master!" Yang Xin's feeling at this moment could only be described as shocking. Lin Zhenhua's operation was like a flowing cloud and water, without any obstacles in between. Yang Xin remembered that normally, his master would take a long time to adjust the degree of separation, counting on his fingers, which was unlike Lin Zhenhua's quick and nimble movements.

  Lin Zhenhua smiled with satisfaction, recalling that he had spent a whole summer vacation learning to be a milling worker in the internship factory of Huaying University. His master was one of the top milling technicians in the country. After the internship, his master wrote on his appraisal: "He has extremely high intuition for mechanical processing, and if placed in a factory, he will definitely be a good worker." He still remembered the look of regret on his master's face when handing him the appraisal, as if saying that such a good worker had gone to graduate school, which was really a pity.

  Before Yang Xin came out of his shock, Lin Zhenhua had already removed the first milled gear from the jig and placed it in a nearby finished product box. He stepped back and said to Yang Xin, "Okay, your turn."

  "Me?"

  "Right, if you don't try it yourself, when will you learn? Don't be afraid, I'll teach you how to do it."

  Yang Xin suddenly had a dazed feeling, as if she had returned to ten years ago, when that boy with a runny nose would say to her at any time: Don't be afraid, I'll teach you...

  "When clamping the workpiece, each claw should be subjected to even force. After clamping, turn it around once to see if the shaft is biased... Yes, that's how you turn it. The calculation method of the dividing head is like this: divide the number of graduations by the number of teeth on the gear, and then select other graduations based on the remainder..."

  Lin Zhenhua spoke with his body, guiding Yang Xin hand in hand. He didn't realize the importance of male-female boundaries. In later years, he had taught undergraduate students how to do metalwork internships countless times at the practice factory, regardless of whether they were boys or girls, and he always taught them by holding their hands. Of course, those post-80s and post-90s girls didn't know that there was such a thing as "not being physically close" in the world. They would unscrupulously stick to Lin Zhenhua's body to watch him operate, completely disregarding certain soft parts of their bodies coming into close contact with Lin Zhenhua's.

  Yang Xin had never been held by a boy's hand to do things, she could clearly feel the temperature of Lin Zhenhua's palm. This warm feeling made her feel a little shy, and at the same time, it gave her a sense of security that was reassuring. She forced herself not to think about those messy things, but instead listened intently to Lin Zhenhua's explanation.

  The first gear, Lin Zhenhua guided her ten times and corrected five mistakes.

  The second gear, Lin Zhenhua instructed five times and corrected two mistakes;

  The third gear, Lin Zhenhua said just one sentence;

  The fourth gear, Lin Zhenhua remained silent from start to finish.

  Yang Xin measured the gear with a vernier caliper, her face lit up with a bright smile after measuring the width of the last tooth: "Success! Success! Xiao Hua Ge, you're really amazing!"

  "Haha, this seems to be something you've made up yourself, I didn't say anything." Lin Zhenhua humbly said.

  "You taught well!" said Yang Xin, "The things my master said, I couldn't understand. But when you explained, I understood everything. The things are still the same, but your explanation is better than hers."

  A good teacher produces excellent students. Although Jiang Tie Mei herself was a skilled worker, her skills were honed through years of practice and she didn't have the same level of innate understanding as Lin Zhenhua. With such skills, teaching Yang Xin would only make Yang Xin feel extremely frustrated. Lin Zhenhua had a deep understanding of mechanical processing principles, he could see exactly where Yang Xin was struggling and always provided timely hints, so in just one hour, Yang Xin learned more than she had in an entire week.

  "There's just one more gear left, and once it's done, we can go back and have dinner." Lin Zhenhua said with a smile.

  "Don't worry, I can handle it in no time." Yang Xin not only learned the machining knowledge taught by Lin Zhenhua, but also picked up his "Yunnan dialect".

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  I watched the milling tutorial many years ago, about the dividing head, I don't know if there's anything wrong, please forgive me if there is.

  10.15 Revision note: Thank you to netizen "Qīng Cuì Yù Dī" for severely criticizing that I didn't understand machine operation, he pointed out that wearing gloves is strictly forbidden during machine operation. After verifying, this was indeed the case, so I corrected and deleted the sentence about wearing gloves.