PDLP Chapter 117 continues
Chapter 117 continues
"Brother Jiang, do you think this is what we'll be doing from now on? Working on coatings and materials, and not repairing machines anymore?"
Jiang Cheng shook his head. "No. The machine is the foundation. Coatings and materials are all for making the machine run better. We can't lose sight of the foundation."
Sun Deming nodded and didn't ask any more questions. He crumpled the oil paper into a ball and threw it into the trash can. The paper ball bounced off the rim of the can and fell in.
The next day, Jiang Cheng received a call from Zheng Yanxi.
Her voice was more urgent than usual, her speech faster, as if she were in a hurry. There was the rustling sound of pages turning on the other end of the phone. "Jiang Cheng, I have an exam next Monday. It's the adult college entrance exam, four subjects. It takes two days."
"How's your review going?"
"It's alright. I did six practice tests and averaged 75 points. But my English is bad; I can't remember the vocabulary. I memorized twenty words yesterday, but I only remembered five this morning."
"Is 75 points enough?"
"That's enough. But I don't want 75, I want 85. The higher the score, the better my chances of getting accepted." She paused, and the sound of turning pages on the other end of the phone stopped. "The city hospital is only hiring two current employees this year, and there are eleven applicants. I have to be in the top two."
Jiang Cheng remained silent for a while. Eleven people were vying for two spots; where did she rank? He didn't know. She didn't know either. They could only wait for the exam results.
He wanted to say, "Don't put too much pressure on yourself," but what came out of his mouth was, "You can do it." Because he knew that she didn't need anyone to tell her to relax; she needed someone to believe that she could do it.
There was a moment of silence on the other end of the phone. The sound of turning pages started again, then stopped. Then she said, "Jiang Yuan learned a new word yesterday."
"What word?"
"Daddy." Her voice lowered, "not the kind of 'Daddy' you used to call out to, but the real one, pointing at your picture. She called out several times, and then smiled. When she smiled, she showed two little teeth, one on top and one on the bottom."
Jiang Cheng gripped the microphone, his throat feeling like it was blocked. He remembered Jiang Yuan's face, the way he strained when he called "Daddy"—his little mouth clenched tightly, as if he were pushing something very heavy out. He remembered Jiang Yuan walking with his arms raised in front of his chest for balance, like a waddling little penguin. He also remembered the first time he held him, so light, so soft, like holding a ball of cotton.
"Wait for me to come back."
"Um."
After hanging up the phone, Jiang Cheng stood in the corridor, holding the receiver and listening to the busy tone. Sunlight streamed in through the window, warming his face. He put the receiver back, his finger lingering on the phone for a moment. There was a crack in the plastic casing of the receiver, extending from where his thumb was pressing to the edge of the earpiece.
At the other end of the corridor, Chief Engineer Chen was walking towards them, holding a document in her hand. Her pace was neither fast nor slow, and her leather shoes made a crisp sound on the terrazzo floor.
"Comrade Jiang Cheng, we have news from Elder Zhou. The people from the Institute of Automation will arrive next Monday. Before then, you need to come up with a plan for the equipment modification. Your center will be responsible for the mechanical parts, and the Institute of Automation will be responsible for the electrical and control parts. The plan needs to be finalized by next Friday."
Jiang Cheng took the documents and flipped through them. It was a thick stack, full of technical requirements and deadlines. He glanced at the calendar—today was Tuesday, next Friday, ten days to go. The calendar hung on the corridor wall, Sundays marked in red, weekdays in black, and next Friday was circled in red by Chief Engineer Chen.
"Chief Engineer Chen, we can come up with a plan in ten days. But there's one problem."
"What's the problem?"
"Controlling the spraying trajectory. The blade shape is complex, and the spray gun needs to move along the curved surface. Existing robotic arms are fixed and can only perform linear and circular interpolation. To move along the curved surface, five-axis linkage is required. Few companies in China can achieve this level of precision."
Chief Engineer Chen looked at him, her gaze somewhat meaningful. She switched the document in her left hand and tapped the cover twice with her right index finger. "So, what's your suggestion?"
Jiang Cheng thought for a moment. He walked to the window in the corridor and pointed to a tree outside. "Chief Engineer Chen, look at that tree. The canopy isn't a flat surface; it's made up of many curved surfaces. If I were to paint the entire tree, I wouldn't need to cover it all from one angle. I could paint the front first, then the sides, then the top. I could paint one area from each angle, with a little overlap between the areas, and that would cover the whole thing."
He turned to look at Chief Engineer Chen. "The blades are the same. We don't aim for one-time molding. We use segmented spraying. We divide the blade into several areas, each using a fixed spray gun angle, and cover the entire curved surface through multiple layers. This way, we don't need five-axis linkage; three-axis is enough. But the spraying time will be longer, and the process parameters will need to be re-optimized."
Chief Engineer Chen was silent for a moment. She walked to the window, looked at the tree for about ten seconds, then turned around and nodded. "This idea is good. Refine the plan and have it ready by next Friday."
She turned and walked away. Her footsteps faded into the distance in the corridor, steady and clear. The sound of her leather shoes changed from crisp to muffled, finally disappearing at the end of the corridor.
Jiang Cheng stood by the window, looking at the sky outside. The sky was blue, the clouds were white, and an airplane streaked across the sky, leaving a long contrail, like a white thread stitching the sky shut. The contrail slowly spread across the sky, thickening, fading, and finally disappearing. He touched the letter in his pocket—the letter that hadn't been mailed. The letter was still there, the edges worn, the creases almost torn. He took it out, glanced at it, and put it back.
In the afternoon, Jiang Cheng convened a small meeting with Sun Deming and Huang Deqing in the laboratory. The laboratory was on the basement floor and had no windows; the fluorescent lights hummed softly. He explained the task of modifying the equipment, then laid a sheet of white paper on the table and picked up a pencil. The pencil was HB, and the tip was already sharpened; he re-sharpened it with a knife.
"Deming, you're in charge of the mechanical parts. You'll design the spray gun's mounting mechanism, the blade clamping mechanism, and the protective cover. Get the sketches out within three days."
Sun Deming nodded, picked up a pen, and drew a few strokes on the paper. His hand was steady, and the lines were straight, a stark contrast to when he first arrived at the center. When he first came, his drawings were crooked and he had to use a ruler to draw a straight line; now, he could draw straight lines with ease.
"Master, you'll oversee things. Please take a look at the mechanical design for Deming. I'll be responsible for optimizing the process parameters."
Huang Deqing didn't speak, only nodded. He squatted in the corner, holding an oilstone, sharpening a scraper. The blade made a soft, even, and drawn-out rustling sound on the oilstone, like a person's breath. Water was poured onto the oilstone, and the resulting slurry was gray. He wiped it with his finger and continued sharpening.