Live Stream 1980: Netizens Teach Me How to Make a Rocket by Hand

A technician suggested in a low voice:

"Engineer Zhao, how about we skip testing at 20,000 RPM?"

"Why not just reduce the RPM to 2000 and try cutting the titanium alloy in low-speed, high-torque mode?"

"Slow down to avoid the fault zone?"

Zhao Qiang turned his head and glared.

"That's called burying your head in the sand!"

"The nominal design limit of this spindle is 20,000 RPM! If it can overheat and seize up even when cutting aluminum alloy at 20,000 RPM, it means our assembly process and spindle rigidity are simply not up to standard!"

"The spindle's dynamic balance is inadequate; it's a defective product."

"Even if you reduce the speed to 2,000 RPM to cut the titanium alloy propeller of a nuclear submarine, the microscopic yaw will ruin the precision of the entire curved surface!"

"What the higher-ups want is a perfectly smooth mirror that can silence the submarine, not diced radishes!"

The workshop fell silent immediately.

No one spoke anymore.

The technological impasse stands before everyone like an invisible wall.

If the speed isn't reduced, the spindle will eventually seize up.

If we deceive ourselves by slowing down, the five-axis machine tool that we have built up with countless resources will forever remain a flawed decoration.

Just then, the heavy, airtight door lit up with a green light.

With a hissing sound as the airlock depressurized, Lin Xi strode into the workshop.

He had just arrived from the airport, and his military overcoat still carried the chill of a winter night in the capital.

Xiao Mo stood outside the door and closed the airtight door tightly.

"Master, Brother Zhao, how is it?"

Lin Xi changed into anti-static clothing and walked into the experimental workshop.

Zhao Qiang sighed and pointed to the scrapped aluminum alloy impeller:

"We've replicated the hardware, but we're stuck with lubricating oil and bearing steel."

"It can't pass the high-speed test. At 20,000 RPM, it will definitely seize up after ten minutes of operation."

Lin Xi didn't speak immediately.

He walked to the machine tool, first looking at the broken tool, then at the blackened spindle housing, and finally reached out and touched the coolant channel through which it flowed.

A few seconds later, he turned to look at the workshop supervisor.

"Go to top-secret vault number seven and bring back those black boxes we bought from Europe last year."

"It contains silicon nitride ceramic bearings."

Li Jianguo was taken aback.

He had spent most of his life working with metals, and the moment he heard the word "ceramics," his brows furrowed.

"ceramics?"

"Lin Xi, ceramics are as brittle as glass, can they really be used as spindle bearings in machine tools?"

Lin Xi picked up a rag, wiped her hands, and explained:

"Master, this ceramics is not that ceramics."

"This is industrial-grade silicon nitride."

"It was specially purchased from Europeans last year."

"If we didn't have what they wanted, they wouldn't have sold it."

At this moment, the live stream in Lin Xi's mind had already exploded.

[For your information, ceramic bearings weigh only 40% of steel bearings, and most importantly, their coefficient of thermal expansion is almost zero!]

[That's right! There's no thermal expansion. No matter how high you rotate it and how much heat it generates, the ball bearings won't expand and get stuck. You don't need that crazy lubricant from Japan at all!]

[Materials science is truly a game-changer! No matter how meticulously you calculate the parameters of your everyday machine tools, it's no match for the streamer's direct switch to a different field.]

Emboldened by the comments section, Lin Xi said to Li Jianguo:

"This thing is not only lightweight, but also extremely heat-resistant."

Thermal expansion is negligible.

"Since steel bearings can't handle the heat, let's switch to a heat-resistant material."

After hearing this, Zhao Qiang's eyes lit up, and he slapped his thigh:

"Understood! I'll personally lead the team to install it!"

......

Three hours later.

The underground workshop was brightly lit.

The brand-new ceramic bearings were carefully installed, the preload was readjusted, and the spindle housing was slowly closed.

The testing machine tool was powered on again.

Zhao Qiang pressed the start button, and the spindle began to accelerate.

10,000 revolutions, 15,000 revolutions, 20,000 revolutions!

Ten minutes passed, then half an hour.

The temperature stopped rising sharply.

The spindle speed remained steadily at 20,000 RPM, without any screeching, jamming, or that chilling metallic whistling sound.

"The spindle isn't stuck!"

"Stable RPM!"

"The technician shouted excitedly."

Before everyone could even rejoice, Li Jianguo, who was in charge of overseeing the processing of the parts, suddenly called for a halt.

The machine tool spindle stops rotating and the cutting tool retracts.

Li Jianguo walked to the workbench and picked up the newly processed aviation aluminum test piece.

His face darkened after just one glance.

He handed the parts to Lin Xi:

"Turning it around won't kill it, but I can't deliver on this job."

Lin Xi took the parts and examined them carefully under the light.

The curved surface, which should have been smooth as a mirror, was now covered with tiny, wavy lines.

When you touch it, you can even feel a noticeable stickiness.

"Shaking knife pattern".

Zhao Qiang leaned over to take a look, and his heart sank.

This is a fatal flaw in machining.

For military components with extremely high requirements for fluid dynamics, even the slightest unevenness on the surface can generate cavitation underwater, leading to severe noise.

By military standards, this would be considered utterly worthless.

"That shouldn't be the case..."

Zhao Qiang walked around the machine tool twice, sweating profusely.

"The guide rail accuracy has been checked, the bearing clearance is correct, and the workpiece clamping is also fine."

"Could it be that the hardness of the ceramic bearing is causing a slight misalignment in the assembly?"

A group of traditional mechanical engineers were at a loss, staring intently at the transmission structure of the machine tool, trying to find the non-existent mechanical defect.

Lin Xi held the scrap impeller and examined it for a while.

In the live stream chat, the comments section was already flooded with messages.

Stop tightening the screws! This isn't a mechanical error; it's a control problem!

[Ceramic bearings are lighter, so their inertia changes, and the original servo parameters will definitely be overshooted.]

[The ultimate goal of mechanics is algorithms! Host, change the PID!]

[Lower the integral gain I to prevent torque from accumulating; increase the derivative D to add damping to the system!]

[Also, the main shaft acceleration curve is too stiff with linear acceleration; it needs to be replaced with an S-shaped, flexible acceleration and deceleration to reduce the strong impact on the structure!]

Lin Xi looked at the comments and suddenly smiled.

"Brother Zhao, stop checking the screws, the problem isn't with the hardware."

Zhao Qiang was taken aback.

"What?"

Lin Xi stepped forward, pulled Zhao Qiang away from the control panel, and sat down at the keyboard of the Bagua OS industrial control terminal.

"Not in the hardware?"

Zhao Qiang was puzzled.

"Where did those sword-wielding patterns come from?"