Volume 1, Chapter 47: Decent

Three days later, Du Yuze placed a thick stack of blueprints on Li Weiguo's desk.

They were not mere rough sketches, but a complete and logically rigorous industrial design scheme. From aerodynamic layout to structural strength, and from material selection to theoretical performance curves, everything surpassed the standards of this era.

Li Weiguo flipped through them page by page. His hands moved faster and faster, and his breathing grew increasingly rapid. Old Zhang and Old Sun crowded behind him, their heads almost bumping into each other.

"This... did you really come up with this all by yourself?" Old Zhang's voice was hoarse.

"A concept, combined with some existing theoretical derivations," Du Yuze replied, leaving no room for criticism.

Li Weiguo abruptly slammed the blueprints shut, raised his head, and stared intently at him. Without asking anything, he grabbed the telephone on his desk and dialed an extension number.

"Old Li! Bring your men to my office! Right now!"

The voice on the other end of the line was as irritable as a grizzly bear: "Director, I'm calibrating the machine tool! No matter how big the matter is, it has to wait until I'm done!"

"Engine blades! Five-axis work!" Li Weiguo roared back, "Are you coming or not?"

There was a three-second silence on the line, followed by a loud crash, as if some tool had been thrown to the floor. "I'll be right there!"

In less than five minutes, a sturdy man wearing oil-stained work clothes and with hair as messy as a bird's nest burst into the room. He was followed by two similarly dressed young men with nervous expressions on their faces.

The man glanced at the blueprints on the desk, then at Du Yuze, and grinned, revealing a row of teeth stained yellow by cigarette smoke.

"Director, is this the job you mentioned that could make the five-axis machine tool smoke?" His name was Li Guishou, the head of the machining workshop at Nanshan Factory, and the most skilled fitter, turner, and miller in the entire factory. For any title ending in "mechanic" or "machinist," he was the founding master.

Li Weiguo pushed the blueprints toward him. "Take a look. Can it be done?"

Li Guishou picked up the top three-dimensional structural drawing, took one look at it, and laughed. He tossed the blueprints back onto the desk with a sharp slap.

"Can't be done."

"Why not?" Li Weiguo asked.

"This isn't a part; it's a work of art." Li Guishou pulled out a crumpled cigarette and put it in his mouth without lighting it. "The twist of this blade, this curvature—it's simply not meant for metal. Tell me, how is the cutter supposed to follow this line? Go in from here and come out from there? The tool holder will snap! That's called interference!"

He pointed to an extremely complex curved surface on the blueprint. "And here, it requires a surface roughness of zero point eight, and the surface strengthening must be uniform. What kind of cutter am I supposed to use? An immortal's fingernail clipper?"

His two young apprentices behind him wanted to laugh but didn't dare, their faces turning red from holding it in.

"Old Li, be serious," Li Weiguo said with a sinking expression.

"I am very serious." Li Guishou took the cigarette out and held it between his fingers. "Director, our five-axis machine tool is a precious asset—imported from Germany, and the only one in the entire factory. It's not meant to be used for a young man's whimsical experiments. With this thing, one wrong cut, and let alone the blade, you might even wreck the machine tool's spindle!"

Du Yuze spoke up. "I've calculated the tool paths and accounted for the interference issue. As long as we use a specific ball-nose end mill and adopt layered machining, it is theoretically feasible."

Li Guishou cast a sideways glance at him. "Theory? On the workshop floor, my experience is theory. You calculated it? Have you ever worked on the shop floor? Do you know how sticky titanium alloy is when cut? Do you know how much cutting heat can instantly deform this thin sheet?"

"I know," Du Yuze replied calmly. "During high-speed cutting of TC4 titanium alloy, the localized temperature will exceed 800 degrees, leading to material hardening and accelerated tool wear."

Li Guishou was momentarily stunned; this kid wasn't just talking idly on paper.

"Therefore, the machining plan I designed includes high-pressure internal cooling and segmented cutting paths to minimize thermal deformation," Du Yuze added.

"Easier said than done!" Li Guishou scoffed disdainfully. "It looks gorgeous on paper, but on the machine tool, it's just a pile of scrap metal! Director, if you believe him, I can't do this job. I won't gamble with the factory's prized baby."

"You!" Li Weiguo slapped the table in anger.

"Director Li," Du Yuze suddenly said, "how about we make a bet?"

Everyone looked at him.

"Let's bet on the first blade," Du Yuze said. "I'll handle the programming, using your machine tool and your cutters. If it fails, I'll take full responsibility. I'll ask the director to let me sweep the workshop floors for three months. If it succeeds—"

"If it succeeds, what then?" Li Guishou asked provokingly.

"If it succeeds, you must follow my instructions completely for all subsequent machining."

Li Guishou burst into hearty laughter, as if he had heard the most ridiculous joke in the world. "Fine! Kid, you've got guts! Director, you heard him—he said it himself!"

***

Li Weiguo looked at Du Yuze. There was not the slightest trace of joking on the young man's face. He was wagering his own future on a technical possibility.

"Alright," Li Weiguo finally nodded. "Old Li, give it to him! The best cutters in the workshop, the best materials, let him try!"

In the machining workshop, the five-axis CNC machine tool representing the highest manufacturing level of the Nanshan Factory was cleared. A square piece of TC4 titanium alloy was firmly secured in the fixture.

Li Guishou crossed his arms, standing outside the safety line with a look that clearly anticipated a good show. The veteran technicians around him also whispered among themselves.

"He's crazy, completely crazy."

"Using a five-axis machine tool for practice? If the cutter crashes—"

Du Yuze ignored them. He input the CNC program he had written into the control system and then personally inspected the tool clamping. Everything was ready.

He pressed the green start button.

The safety door of the machine tool slowly closed, and high-pressure coolant began to spray, its hissing sound making people's hearts tense up. The spindle began to rotate, emitting a low hum.

Everyone held their breath.

The cutter made contact with the titanium alloy block.

"Screeech—!"

A piercing, grating frictional sound instantly pierced through the entire workshop! It sounded like fingernails scratching desperately across glass, setting everyone's teeth on edge.

Immediately afterward, there was a crisp "bang"!

Sparks flew in all directions!

The machine tool shuddered violently, triggering an overload alarm, and a blinding red light flashed frantically. The spindle came to an abrupt halt.

It had failed.

Li Guishou couldn't even be bothered to mock him; he simply shook his head and turned to leave.

"Wait a moment!" Du Yuze called out.

He walked quickly to the console and pulled up the machining log from just moments ago. In his mind, the system prompt was exceptionally clear.

[Warning: Tool resonance detected at 8750 RPM, cutting force overloaded by 35%.]

Resonance...

"The spindle speed was too high," Du Yuze muttered to himself.

"Duh!" Li Guishou stopped in his tracks and turned around. "I told you long ago that your theory simply doesn't work! You can't use high speeds with titanium alloy!"

"No, it's not that we can't use high speeds; it's that we shouldn't use 8750 RPM," Du Yuze raised his head. "That speed formed a resonance with the natural frequency of the cutter."

"What nonsense are you talking about, resonance?" Li Guishou looked impatient. "Change the cutter! Change the material! I refuse to believe this!"

"Changing them won't help," Du Yuze walked up to him. "Director Li, trust me once. Lower the speed to 7200 and increase the feed rate by 5%."

"You're still going?" Li Guishou flared up. "Lower the speed and increase the feed? Do you want to snap the cutter in half? Kid, like I said, on the workshop floor, I am the rule!"

"Then let's bet again!" Du Yuze did not back down. "Use this same scrap material, use the exact same program, and just change those two parameters! If the cutter breaks again, I'll leave immediately and never set foot in your workshop again!"

The standoff between the two men made the surrounding air feel frozen.

Li Weiguo had arrived at the workshop at some point. Standing behind the crowd, he remained silent and simply watched.

Finally, Li Guishou squeezed a few words through his teeth: "Fine! Today I'll make you lose and accept it wholeheartedly!"

A new cutter was installed, using the same titanium alloy block with one corner already milled away.

The program was reset.

Du Yuze pressed the start button once more.

***

Everyone's heart leaped into their throats.

The spindle began to spin, its sound lower-pitched than before. The cutter bit into the metal once again.

"Hiss..."

This time, there was no piercing screech, only a steady, continuous cutting sound. Although the sound was still loud, it was the sound of "working," not the sound of "destruction."

Silvery-white metal chips flushed out by the coolant splattered everywhere like snowflakes.

Li Guishou's expression changed. He stared intently at the cutter tip through the observation window. The steady movement and smooth trajectory looked nothing like the breakage he had anticipated.

Time ticked away second by second.

Half an hour later, rough machining was complete. A vague blade outline appeared on the titanium alloy block.

"Stop!" Du Yuze suddenly called out.

The machine tool paused.

"What is it?" Li Guishou asked nervously.

"Thermal deformation," Du Yuze pointed to a temperature curve on the screen. "We must modify the next finishing path, starting from the blade pressure side rather than the back. We need to use the cutting stress of the subsequent operation to counteract the thermal stress of the previous one."

Li Guishou understood these words. These were techniques that veteran craftsmen could only figure out through years of experience and tactile feel, yet this kid had calculated them simply by looking at data?

He raised no further objections and silently watched Du Yuze modify the program.

The next few hours turned into a bizarre collaboration. Like a prophet, Du Yuze continuously used the real-time data refreshed in his mind to anticipate potential problems in advance.

"Next cut, reduce depth of cut by 0.02 millimeters; vibration is about to exceed limits."

"Increase the coolant pressure a bit more; the temperature at quadrant angle A is too high."

"Pause! The cutter has a minor chipping, change to cutter number three!"

From initial resistance to shock, then to numbness, Li Guishou eventually began executing Du Yuze's every command subconsciously. He and his apprentices had effectively become Du Yuze's hands.

When the final finishing program finished running, the spindle slowly came to a halt.

The entire workshop fell utterly silent.

The robotic arm retrieved the component and placed it on the inspection table. It was a complete titanium alloy blade with complex three-dimensional curves. Under the lights, it radiated a cold and precise luster, like a work of art from the future.

Li Guishou put on white gloves and picked it up with extreme care.

Without using the coordinate measuring machine, he simply brought it before his eyes, using the most sensitive pads of his fingers to slide inch by inch from the root of the blade to the tip.

Feeling the perfect twist angle, the mirror-smooth curved surface, and the razor-thin edge.

His hands were trembling slightly.

"Go test it," he handed the blade to his apprentice, his voice hoarse.

A few minutes later, the apprentice ran back holding a printed report with an expression of disbelief.

"Master... all dimensions passed completely! The maximum error does not exceed three microns!"

Li Guishou snatched the report, gazing at the dense rows of data, every single one of which struck his heart like a hammer.

He looked up at the young man still standing before the console.

Du Yuze was looking back at him, his face devoid of any triumphant expression, showing only a trace of exhaustion.

Li Guishou opened his mouth, and the words "Kid, you win" rolled around in his throat for a long time, but he couldn't get them out. In the end, he simply gripped the blade—into which countless efforts had been poured—tightly in his hand.