78: Bringing his wife and children to Harbin Institute of Technology

After Liu Xiaojun finished speaking, he immediately crawled behind the press to get to work.

The heating rod is inside the press, and the protective cover must be removed to reach it.

Mr. Li handed over a wrench, while Liu Xiaojun tightened the screws one by one.

After removing the protective cover, six heating rods were revealed inside, arranged in a row.

Liu Xiaojun started testing them one by one, and when he tested the fourth one, he found a problem.

"This one is dead."

"Change."

Liu Xiaojun ran to the warehouse and found a new heating rod.

Liu Xiaojun unpacked the package, applied thermal grease, and carefully inserted it.

After installation, Liu Xiaojun couldn't wait to power it on and start testing.

The temperature gauge on the machine showed that the temperature started to rise, and then suddenly stopped when it reached 180 degrees Celsius.

Liu Xiaojun looked at the thermometer and then at his watch, observing for a full five minutes before concluding that the temperature had stabilized.

"Alright, things are stable."

Ye Bingwen glanced at his watch; it was 6 p.m., exactly two hours later.

"Pressure test."

Chen Anze, who was eager to try, had already finished laying the layers.

Seeing this, Master Li moved the steel mold onto the press, closed the mold, and started the machine.

Everyone held their breath and stared intently at the thermometer.

The pointer remained steadily at the set value and did not move.

The mold was opened sixty minutes later.

Chen An took the part out and measured it with a roughness tester.

The data is half a level higher than ▽7.

Liu Xiaojun shouted excitedly.

"Alright! You passed!"

Fearing disclosure, Chen Ansheng came over and tested it again.

After the test, Chen An had a bad feeling.

"No, the size is wrong."

Chen An handed the calipers to Ye Bingwen, who then measured them again.

The length is 220.3 millimeters, the drawing requires 220, the tolerance is ±0.5, and it exceeds the tolerance by 0.3.

"How could this happen?"

Liu Xiaojun couldn't believe it, so he quickly squatted down to look at the mold and then at the pressure gauge of the press.

"With increased pressure, the temperature distribution of the new heating element is different from the old one, and the amount of thermal expansion has changed."

Liu Xiaojun took out a calculator and spent a long time calculating before reaching a conclusion.

"We need to reduce the pressure by eight percent and decrease the heat preservation time by five minutes."

Ye Bingwen felt that there was simply not enough time.

Ye Bingwen glanced anxiously at the time on the wall:

"How long will it take to adjust it and then test it again?"

"Try another batch, one hour."

"try."

Liu Xiaojun readjusted the parameters, tightened the screw, and reset the time.

The second batch, sixty minutes later.

Chen An measured it again, and the length was 219.8 millimeters, which was within the tolerance range.

The surface finish meets the standards.

Chen An breathed a sigh of relief upon hearing this.

"Alright."

Seeing this, Ye Bingwen, who was standing to the side, still dared not slack off.

Ye Bingwen glanced at his watch; it was already eight o'clock in the evening.

From 4 pm until now, four hours have passed, and only one qualified piece has been made. The twelve returned pieces need to be remade, and the remaining forty pieces need to be made, for a total of fifty-two pieces.

Three days, seventy-two hours, sixty-eight hours remaining.

"Keep up the good work, everyone."

Instead of complaining, everyone turned around and threw themselves back into their work.

Master Li restarted the press.

Liu Xiaojun squatted down beside him, staring at the thermometer.

When the first batch went in, Liu Xiaojun recorded the temperature every five minutes.

The temperature fluctuations were slightly smaller in the second batch than in the first, but they were still present.

Liu Xiaojun took the notebook and did some calculations.

"It still needs to be adjusted."

"Reduce the pressure by another three percent, and increase the heat preservation time by two minutes."

Ye Bingwen looked at him and said:

"At this rate, when are you going to finish adjusting it?"

"Adjust until it's stable."

"We'll adjust as we go, we can't wait any longer."

Chen An, however, felt it was too risky.

"Director Ye, what if we mess things up while we work on it?"

"If it's ruined, we'll redo it. It's better than just sitting here waiting."

After Ye Bingwen finished speaking, he continued speaking to Liu Xiaojun:

"If you adjust the parameters for one batch now, you should use the new parameters for the next batch. If it passes the test, continue making it. If it fails, adjust the parameters again. You cannot stop and wait."

Upon hearing this, Liu Xiaojun gritted his teeth and replied:

"OK."

The third batch will be made according to the new parameters.

After the third batch came out, the dimensions and the surface finish were up to standard.

The fourth batch, produced using the same parameters, showed a deviation in dimensions again.

Without much thought, Liu Xiaojun adjusted the parameters again.

The fifth batch went astray.

The sixth batch went astray again.

Liu Xiaojun put all the data from these furnaces together and studied them for a long time.

"The temperature curve of the heating rod is not linear. It rises slowly when it is first turned on, but it stabilizes after it starts running."

Liu Xiaojun recalculated the parameter table.

Use one parameter for the first three furnaces, another parameter for the middle three furnaces, and then use a stable parameter for the rest.

Chen An frowned when he saw the table:

"So thin?"

"If you're not careful, you won't be able to stay stable."

Ye Bingwen made the decision immediately after reviewing it:

"Follow Xiaojun's instructions, record each batch one by one, and match each batch to the standard."

Starting from the ninth furnace, the parameters stabilized.

The finished parts all have medium-sized dimensions and a surface finish of ▽7 or higher.

Chen An filled in the test data on the wall, and the pass rate line returned to 100%.

Liu Xiaojun squatted next to the press.

Master Li came over and handed Liu Xiaojun a cigarette:

"Have a smoke and take a break."

"Don't smoke, but keep an eye on it."

"If you keep an eye on it, it won't run away."

"They escaped right under our noses last time."

Master Li lit his cigarette and didn't say anything more.

It slowly got to midnight.

The workshop was still brightly lit, and no one was taking a break.

Zheng Shuyun stood next to Ye Bingwen and watched him eat.

Zheng Shuyun went back around 10 o'clock to put An'an to sleep and then came back.

Zheng Shuyun brought her own lunch, wrapped the lunchbox in her cotton-padded coat, and it was still hot when she arrived at the factory.

Ye Bingwen took the lunchbox but didn't eat.

"Is An'an asleep?"

"I'm going to sleep now. Grandma Wang next door will watch the house for a while."

Ye Bingwen was relieved after hearing this, opened his lunchbox, and took a couple of bites.

"You eat too."

Zheng Shuyun shook her head:

"I'm not hungry."

"You have to eat even if you're not hungry, because you have to work another day tomorrow."

Zheng Shuyun didn't refute, and took a steamed bun and started eating.

Liu Xiaojun was eating next to the press, keeping an eye on the temperature gauge as he ate.

Master Li hadn't eaten; he was leaning against the milling machine with his eyes closed.

Upon seeing this, Ye Bingwen walked over:

"Master Li, time to eat."

Master Li shook his head:

"Take a break, I don't have an appetite and can't eat."

"You have to eat even if you don't have an appetite, and you'll have to take over for me in the middle of the night."

Master Li couldn't refuse Ye Bingwen's offer, so he took the lunchbox and ate a few bites.

After that, no one spoke in the workshop; only the hum of the machines could be heard.

The next morning at six o'clock, it was still dark.

Liu Xiaojun is already in the workshop.

He didn't go home all night; he just leaned against the chair next to the press all night.

I wake up every half hour to check the thermometer and then the pressure gauge, and then go back to sleep.

When Chen An arrived at 7 o'clock, Liu Xiaojun was squatting in front of the press recording data.

"You didn't go home last night?"

"They went back, and now they're back again."

Chen An looked at the notebook; there were records for every hour: 2 AM, 3 AM, 4 AM, and 5 AM.

"You didn't sleep all night?"

"I took a nap."

Chen An didn't ask any more questions, picked up the test report for that day, and started working.