Chapter 23 — Wind Village Robot Team

"Cut here, exactly four centimeters." Nam said, his hand firmly holding the aluminum ballpoint pen shell on the metal table of the auto repair shop, while Phong used a small saw blade folded in the handle of Mr. Tu's screwdriver, cutting decisively through the thin aluminum shell.

The owner of the car repair shop - a middle-aged man named Phu, was initially surprised when he saw the group rushing in to ask to borrow tools, but when he heard Khanh Dan briefly explain the situation, he immediately cleared a corner of his desk, gave them pliers, soldering irons, and a box of odd screws to choose from.

"Just do it, I won't charge you anything, I just hope the kids will be on time for the exam." He said, standing back in a corner to observe with undisguised curiosity.

Gia Han sat at her laptop, connecting the old Arduino circuit board Phong brought along, typing quickly to edit the pin diagram to match this old version - a job that should have taken half an hour of careful comparison, now she had to do it in a state of trembling while trying to keep her mind awake.

"Ultrasonic sensor pin changed from pin 9 to pin 7, picker arm changed from pin 10 to pin 11." She muttered, typing and reading aloud to check herself so she didn't miss any steps. "The gold block processing code I wrote last night is still on the laptop, just reload it, it won't be lost."

Meanwhile, Nam and Phong struggled with their broken arms. The aluminum tube cut from a ballpoint pen shell was smoothed at both ends with sandpaper given by the shop owner, and tried to fit on the spindle - a surprisingly tight fit, as if the item was born for this very moment.

"Just right!" Phong shouted, unable to hide his relief, but immediately after that he frowned. "But how long can an aluminum tube be this thin? What if it breaks in the middle of the exam?"

"Let's reinforce it." Nam said, having seen the problem before Phong even said it. He rummaged through the borrowed toolbox and found a small piece of copper pipe just enough to fit over the aluminum pipe like a layer of armor, tightening it with two rounds of plastic strapping tape given to him by the shop owner. "Copper pipes are much harder than aluminum. With this extra layer, the shaft can withstand much better force."

The pick-up arm was reassembled and tried to open and close a few times — stronger than Nam expected. But when he attached it back to the robot's body, another problem emerged: the servo motor controlling the gripper, due to the strong impact during the accident, had become misaligned on its internal axis, no longer rotating at the correct angle as before.

"This servo is really broken, it can't be fixed." Nam said, his voice lowered after a while of trying to adjust it without success.

Khanh Dan looked at the clock — seventy minutes left. She looked around the auto repair shop, her eyes stopping at a small table fan running on the shop owner's shelf, a mini fan powered by a small motor similar to the servo they needed.

"Uncle Phu." she asked. "Do you have any spare servo, a small one for that model? Or do you have a motor of similar size, we can try to recreate it."

Uncle Phu scratched his head in thought, then rummaged through a drawer containing miscellaneous items left behind by guests, pulling out a small box containing a few broken remote control toys left by his son many years ago. "I have these, I don't know if I can use them. My son played with them when he was little, but now he's grown up and has forgotten them."

Nam opened the box, his heart beat fast when he saw that there were exactly two small servos inside, one of which worked well when tested with batteries. He quickly disassembled it and compared it with the old servo. The dimensions didn't exactly match, but they were close enough that they could be temporarily installed by drilling a new hole in the bracket.

"Alright!" He shouted, installed the new servo, tried opening and closing the gripper - the movement was as smooth and precise as the old servo.

Meanwhile, the most difficult part is still unfinished: "Wind Eye" - the color sensor tube is cracked, the blue LED is broken and cannot be reused. Uyen Nhi sat quietly looking at the pile of debris in her hand, her eyes were still red from earlier, but she didn't cry anymore, just focused on thinking.

"I don't have a spare blue LED." She spoke, her voice shaking but clear. "Without Wind Eyes, the robot cannot distinguish colors and cannot pick up any blocks correctly."

Khanh Dan looked around the car repair shop again, and her eyes stopped at a small flashlight hanging on a hook near the door, the type of headlight used by car mechanics, with three light modes: white, red, and blue to check the color of the wires in the dark.

"Uncle Phu, is that flashlight for sale? I'll buy it again." She asked, pointing at the lamp.

"You just take it, I'll give it to you, why pay money now?" Uncle Phu waved his hand, took down the lamp and gave it to her.

Uyen Nhi held the flashlight, her eyes lit up. "This light is available in three colors, I don't need to remove the LED anymore, just fix the flashlight in the right position, punch enough holes for light to shine through the tube, use the relay pin to control each color on and off with the signal from the Arduino."

"We don't have a relay." Gia Han interjected, still engrossed in the command.

"But there's a small transistor in the spare parts box I brought with me. Can I use it temporarily?" Phong asked, already pulling out a small bag of spare parts that he always carries with him just in case, a habit he learned from his grandfather.

"Okay, transistors are more flexible than relays." Khanh Dan replied, feeling a sense of hope growing in her heart as he saw each piece of the solution gradually fit together, not thanks to any miracle, but thanks to the little things each person on the team had quietly prepared, brought, or learned over the past many months.

The whole group started reassembling from scratch, each person doing a part, no one needed further direction because they all understood their roles so well that they could coordinate themselves smoothly as if they had practiced for this chaotic moment before, even though in reality, no one had ever imagined a morning like today.

With only twenty minutes left on the clock before the scheduled return to the arena, the robot - now in a much more patchwork shape than its original neat version, with a piece of copper-coated aluminum pipe as the pick-up arm, a mechanic's flashlight temporarily attached to replace the old "Wind Eye", and an old-fashioned Arduino circuit board running the program that had just been hastily reloaded - finally successfully ran a full test on the auto repair shop's brick floor, correctly picking up all three colors of the small wooden block. The shop owner let me borrow it temporarily to try.

"Run!" Uyen Nhi screamed, hugged Gia Han, both burst into tears, but this time the tears were completely different from before.

Khanh Dan looked at the patchwork robot in front of her eyes, then at all four students hugging each other in the middle of a car repair shop full of tools, sweating profusely, their faces smeared with grease, and she felt a greater pride than she had ever felt during her two years working at NovaTech.

Before leaving the shop, Khanh Dan turned around and held Uncle Phu's hand tightly, her voice choked with genuine emotion rather than the urgency of work. "Thank you, we don't know what else to say."

"It's nothing, thank you." Uncle Phu waved his hand, but his eyes were also a bit emotional when he saw the group packing up their things to prepare to leave. "I only lent a flashlight and a few tools, but the machine runs thanks to the efforts of these kids. Let's go, before we're late."

He also put the second flashlight in Uyen Nhi's hand that was left in his son's old toy box, in case the one attached to the robot had problems along the way. "Bring a spare, maybe you'll need it."

The whole group hugged the cardboard box - now lined with many more layers of newspaper that Mr. Phu had found to absorb the shock better than last time - and ran quickly to the car, where Mr. Tuyen had started the engine and was waiting a few minutes ago. This time, Nam and Phong together held the robot box tightly the whole way, not letting go for even a second, while Gia Han still held the laptop open, checking each command line one last time while the car rolled away.

"Fifteen minutes left." Khanh Dan looked at her watch and noticed that when the car turned onto the road leading to the stadium, the familiar dome building appeared in the distance.

No one said anything more. The whole car was immersed in a tense silence, but there was no longer panic like two hours ago, instead there was a quiet concentration of those who had done everything they could, now just waiting to see how their achievements would be tested on the real stage.

Khanh Dan turned to look at the patchwork robot being held tightly between two rows of seats by Nam and Phong. The afternoon sunlight through the glass door shone on the worn aluminum shell, on the brand new reinforced copper pipe, and on the car mechanic's flashlight temporarily mounted where the original "Wind Eye" used to be. It no longer looked exactly like the sleek robot they had been practicing for months, but in some ways, it resembled the exact spirit the team had carried with them from day one: not perfect, but always finding a way to keep going.