Cai Tianming chatted for a while before quietly leaving.

As soon as he left, the eyes of the other three couldn't help but turn to Gu Fei.

Gu Fei understood what the three of them meant.

He patted the thick stack of parts and said, "We can split up now." Continuing here for finite element analysis and motion simulation exploded diagrams. The other end is to make physical objects. Fabricating physical objects is not something that can be done in a moment. Now that the time is a bit tight, everyone is hurrying up. ”

"Gu Fei, you have the most experience among the four. If you think you should do something, just say it, and everyone will listen to you. Lin Chunhui responded directly.

The other two nodded silently.

"In that case, then I'll just say it. ”

Gu Fei smiled and looked at the three partners in the circle room and said, "That's good." Here's how it is now. Ansheng has some health problems, and I have to go to work most of the time. So it's a lot of trouble to make physical parts, and it's a blessing for both of you, Amon and Anjing. ”

Lin Chunhui and An Jing didn't have any surprised looks on their faces, they just looked at Pang Ansheng next to them with a bitter face.

Pang Ansheng was so depressed that he almost wanted to punch his skinny chest a few times.

Gu Fei hurriedly stopped him and continued.

"As for finite element analysis and motion anti-fidelity and explosion diagrams. Well, I'll do a finite element analysis. Amon first made a simple explosion diagram and motion simulation. If you have time to come back at night, you can also help An Sheng draw an explosion picture. Anyway, these can be done separately. ”

Lin Chunhui and An Jing hurriedly nodded in response.

Gu Fei thought carefully for a while before he said slowly: "I estimate that even if everyone completes all the work on the computer, they should still have to wait to complete the physical object."

In the next time, you will prepare for the defense of the competition. Ansheng, the two of you prepare PPT or video copywriting. Make a few more copies in case you need them. Wait for the real thing to be made, if you don't use any changes, everyone can use it and wait for the game. ”

"Hehe, your eldest young master Gu is easy. An Jing joked: "When you open your mouth, you put yourself away." The three of us were busy all day and night. ”

Gu Fei shook his head and said, "I'm not easy either. Every day when I come back from work, I have to check the production of the corresponding physical object. Lest you be sold and help others count the money, such as buying a bunch of bad products and coming back with a happy one. Do you believe it or not?"

The three high-achieving mechanical students looked at Gu Fei with disdain, decisively disbelieving.

Gu Fei was helpless, so he had to give three Xiaobai examples.

He flipped through the parts drawings on the table and picked one at random.

"For example, the hinge base in front of me, well, the designer is Anjing. Ann, you should know what the most important thing about it is, right?"

An Qing stretched out her head to take a look.

She naturally recognized her handwriting, and hurriedly pointed to the three internal thread holes on it, and said: "Of course I know, the most important part of this part is the shape and position of the three M10 internal threads." ”

The other three were not rookies, and after a few glances, they nodded approvingly.

Gu Fei smiled: "Very good." Then dare to ask Miss An, if this part is made. How can you be sure that the thread is not qualified?"

"It's not ......simple," An Jing just opened his mouth, and suddenly froze there speechless. Because she found that she really didn't know how to inspect a threaded hole.

"Hehe, what about the two of you?" Gu Fei turned his head and asked the two big men again.

"Bullying us Xiaobai, right? Wait for me to save my mother first. Pang Ansheng hurriedly picked up his mobile phone and went online.

"Don't worry about it. I can tell you that there is a kind of gauge called thread gauge and also called dental gauge. It is used to detect whether the thread is qualified. Gu Fei responded.

"Then when the time comes, wouldn't it be good for Amon to find a thread gauge to test it?" Pang Ansheng put away his mobile phone, still very unconvinced: "Why do you have to make a move?"

Gu Fei ignored him, just shook his head and went on.

"There are two ends of the thread gauge, and these two ends are actually two external threads. One end is called the general rule, and the other end is called the stop rule. Generally speaking, the diameter of the stop gauge is larger than that of the general gauge. Its detection usage is called: pass the regulation, stop the regulation. ”

This means that when testing with a relatively small gauge end, the entire thread must be able to twist through. When testing with a relatively large stop end, you can only pin in one or two turns at most, but not turn it all over. ”

"This test method is very simple and clear, isn't it?" Gu Fei asked.

The three of them were a little confused, so they had to nod.

"Good. However, the reality is not that simple. Gu Fei smiled hesitantly: "I once encountered such a thing. When using a gauge to detect a threaded hole, it becomes a general and irregular stop. ”

The rules don't work, and the rules don't stop?

The three of them were a little stunned, blinking blankly, not understanding what was going on.

The results of this test show that when the same threaded hole is detected, the result is that the small gauge is not twisted in, but the large gauge is in?

How is this possible?

As soon as Gu Fei saw it, he knew that the three of them couldn't understand it at all. He laughed and slowly explained why.

"Actually, it's very simple. When machining ordinary coarse threads like M10 in CNC, a drill is used to punch holes in the corresponding position, and then a milling cutter is used to expand to a suitable bottom hole. Then change the tooth knife to tap the teeth. ”

"The machining center is claimed to be high-precision and high-XX, but it is not necessarily meaningful. Because when performing a lot of machining, the quality of CNC tools is far more important than the accuracy of the machine tool itself. For example, when drilling or milling holes, due to tool runout or material reasons, sometimes a standard straight cylindrical hole will be made into a large top and small bottom or large bell hole. ”

"Of course, the difference between the ends of this horn hole is actually very small, and the eye can't see it anyway. Ordinary calipers are also undetectable.

When we inspect this hole or thread. Use the small head to detect the general gauge end, which happens to meet the small end of the bell mouth, so the general regulation is not passed. However, when I changed the big end to the gauge end, I happened to encounter the end with a large bell mouth, so the stop gauge was not stopped. ”

Lin Chunhui understood, he thought about it with a wry smile for a while, and said: "Then when we go to test, the two ends of each thread are tested with a pass and stop gauge, wouldn't it be good?"

Gu Fei was noncommittal, just smiled.

"Your Dharma thinking is too naïve. It's useless for you to test like that. ”

"This thing designed by Anjing is okay, it's not very valuable, and it's not distressing to break one or two. Maybe no one will be interested in it.

And many extremely expensive parts are made of very valuable materials. For example, I've seen some U drills, which are a little bigger than our calves, and a drill bit can buy back an Audi, note that it's not Alto!

This kind of part is often scrapped because of such a small problem. So what to do?"

The three of them were a little stunned, and Gu Fei didn't wait for them to reply, and continued directly.

"Just throw it away? That's impossible. Maybe weld the material back and then re-punch the teeth?

Everyone is a mechanic and knows the consequences of doing this, and basically the mechanical properties of materials are completely meaningless. So a lot of people will find a way to fake. ”

"The end of the stop gauge shows that the hole is bigger. Just knock the thread with something to make some threads deform slightly. The stop rule is easy to stop. And if the rules don't work, it means that the hole is small. It's not easy for Kong Da to shrink, but Kong Xiao wants to zoom in, so it's easy, just expand it slightly. ”

"This kind of fraud is difficult to detect with ordinary inspection tools. The buyer has not used it for a few days after buying it, and the parts can easily break. Let the buyer have a bitterness and can't speak.

In the history of domestic export of mechanical parts and even various products, there are really many cases of this kind of crooked and heretical ways. These reluctantly changed domestic products not only pit many Chinese people, but also pit many foreigners.

In many cases, the reputation of our domestic products is ruined in this way. ”