The fact that her tool cabinet had been ransacked was like a thorn in Liu Li's heart. She didn't make a fuss, but every day she would stuff her design drawings and calculation notes into a canvas bag, take them back to her dormitory, and lock them in a box—she couldn't afford to make any mistakes before she had finished making something.

Fu Jingchen's side went smoothly; a week later, he brought a complete set of official drawings to the workshop. The lines on the paper were straight and even, and each dimension was marked with tolerances. Even the size of the screws and the depth of the holes were clearly written.

"The machine repair workshop has agreed to help make the parts!" Fu Jingchen's eyes lit up. "Just confirm these installation dimensions, and we can start work tomorrow."

Liu Li compared the blueprints to the lathe and pointed out several locations that needed to be measured on-site. During the lunch break, when no one was in the workshop, the two got busy—Fu Jingchen took out a small notebook to record data, while Liu Li skillfully turned the handwheel and used calipers to measure the spacing of the guide rods and the height of the slide box, leaving no corner unchecked.

“We need to add a shim here,” Liu Li said, pointing to the optical bar connector. “This lathe has been used for several years, and the interface is a bit worn. If we install it directly, it will wobble.”

Fu Jingchen quickly wrote it down: "These things can't be seen on the blueprints. It's all thanks to your familiarity with lathes."

The data was submitted, and the machine repair workshop started work the next day. While waiting for the parts, Liu Li divided her time in half: she worked diligently in the morning, not only completing the quota but also voluntarily machining a few extra parts; after finishing her work in the afternoon, she would sit at her workstation and draw installation sketches. Master Wang saw this but didn't say anything, and would occasionally hand her a ruler.

"I heard the mechanics are making parts for you?" Sun Peng swaggered over, tapping Liu Li's workbench with his finger. "Don't let the parts pile up and you be unable to assemble it, wasting the factory's resources."

Liu Li was adjusting the cassette without even looking up: "Whether it works or not, we'll know once we try it."

A week later, Fu Jingchen arrived pushing a small cart with shiny parts on it—the connecting rods were polished, the sliders were smooth, and even the small screws were tightened neatly.

"Now it's your turn." Fu Jingchen laid out the parts, his tone full of anticipation.

Installation was more difficult than expected. The drawings looked fine, but problems arose during actual assembly: a screw hole was off by half a millimeter, requiring careful filing; the slider was too tight, necessitating grinding down some edges. Liu Li patiently adjusted each part one by one, while Fu Jingchen handed her tools and drawings, occasionally lending a hand.

Master Wang didn't come to help, but he always seemed to "pass by" at crucial moments. Seeing them struggling to install the connecting rod, he leisurely remarked, "Leave a two-millimeter gap; the machine will expand when it's running." Seeing Liu Li tightening the lock nut, he added, "Use two nuts against each other to prevent loosening." Each time the master gave a tip, Liu Li quickly wrote it down—these were tips she couldn't learn from books.

The most crucial step was installing the transmission linkage, as this directly determined whether the blade tip could travel in an arc. Liu Li measured the dimensions three times to ensure everything was correct before slowly tightening the screws with a wrench.

"How about we try it out?" Fu Jingchen rubbed his hands together, his voice a little tense.

Liu Li took a deep breath, checked all the parts, and nodded: "Try it."

Before anyone knew it, several people had gathered around—the experienced workers had put down their work, all wanting to see what was going on; Sun Peng also stood to the side, arms crossed, his eyes cold.

Liu Li pressed the switch, and the spindle began to hum. She gently pushed the feed handle, and everyone's eyes were fixed on the tip of the blade.

It went smoothly at first, but as soon as the blade tip touched the workpiece, there was a sudden "squeak" that was so piercing it made your teeth ache!

"Stop the car!" Mr. Wang shouted.

Liu Li quickly turned off the machine and looked down—the guide slider was installed crookedly, rubbing against the slide plate. Her heart sank; she had failed on her first attempt.

"Take it apart and readjust it." Master Wang walked over, picked up the slider and looked at it. "It's good that it can turn on the first time, don't panic."

Fu Jingchen chimed in, "New things always need adjustments. The blueprints I drew before took five or six tries to get right."

Liu Li nodded, picked up a wrench, and began to disassemble. The people around her didn't disperse; they watched as she removed parts, identified problems, and made adjustments little by little. Sun Peng's lips curled up, a hint of schadenfreude in his eyes.

She adjusted and reassembled it, testing it again and again, going back and forth three times. Each time she failed, Liu Li became more determined—the first time the slider was crooked, the second time the connecting rod length was slightly off, and the third time the lubrication was insufficient.

By the fourth test run, it was already dusk, and the setting sun shone through the workshop windows, bathing the machines in a golden glow. Liu Li's hands were steady as she slowly pushed the feed handle.

This time, there was no harsh noise, only the soft, even "swish" of the blade cutting through the workpiece. Even more impressive was the smooth, round arc the blade traced on the workpiece, neatly catching even the metal shavings!

"It's done!" Fu Jingchen shouted first.

Liu Li didn't stop until she had finished machining the entire ball head. She picked up a micrometer, her hand trembling slightly, and measured it—the dimension was exactly in the middle of the tolerance, and the surface was so smooth it could reflect a person's image, even more uniform than what an experienced craftsman could machine by hand!

The experienced workers around nodded, and some even clapped. Zhang Shulan ran over and grabbed Liu Li's arm: "Lili! You're amazing!"

Master Wang picked up the ball head, held it up to the light, and examined it. He then touched the surface of the ball with his hand, and finally a smile appeared on his lips: "Not bad."

Only Sun Peng, his face ashen, didn't say a word, and turned to leave.

Liu Li looked at the ball head in her hand, her eyes welling up with tears. All the pent-up frustration, sleepless nights, and sweat she had endured were worth it at this moment.