Patching is not a very wasteful job, helping to patch for half an hour, Li Jiayin came up with the idea of doing his own thing.

Looking around, Li Jiayin decided to say something straightforward: "I'll go back to the classroom and get something." ”

The others looked at her and did not object.

So Li Jiayin went back to the classroom and took over the model design drawings that he was actually still in the stage of writing.

In order to draw the picture, she specially bought a particularly large full-open paper, and after the drawing is completed, she can directly spell it in equal proportions, without thinking about the problem of scaling.

The link of spelling is simple, then the link of drawing is more complicated, the larger the picture, the higher the difficulty of controlling the proportion, for which Li Jiayin also specially bought two half-meter-long steel rulers, which look like murder weapons when placed on both sides of the schoolbag.

Holding a rolled-up piece of open paper, three pencils of different thicknesses, and two steel rulers and compasses, Li returned to the physics laboratory.

Speaking of which, they also helped her by calling her over, the fully open paper is much larger than the desk, and it is very inconvenient for her to draw in the classroom.

The laboratory is different, the large laboratory table can completely spread out the paper, and she can also stand up and look at the overall situation to better adjust the overall direction of the diagram.

Seeing her come over with so many guys, many people cast confused eyes at her.

Cheng Zheng asked directly: "Brother Jia, what are you doing with such a big battle?" Are you sure you can do it? ”

Li Jiayin thought for a moment and replied: "Make a model, look at the situation, if you can't finish it, let it go and get a small one first, and keep the big one for next year." ”

That's a good answer.

With this kind of thing, Li Jiayin is actually a journeyman, listening to other people's discussions while drawing, and can basically achieve double line parallelism.

The progress on their side is actually not slow, it is about half an hour to type a big knowledge point, and the teachers are just like that.

However, after all, there are nine subjects offered in the first year of high school, and it will take at least ten days to complete them all, and it must be used to the extent that other spare time is used at the same time.

In addition to the content of the first year of high school, there is also the content related to the high school entrance examination that needs to be supplemented, not to mention that it will take three or four days, and the time is also full, which is not much lighter than Li Jiayin's task.

In this night's self-study, Li Jiayin basically achieved her goal, and the design drawings were basically completed, and she was a little surprised that she could complete it so quickly.

The completion of the design is only the beginning, and the real part of the follow-up is the complex part.

The bridge that Li Jiayin wants to make is divided into three main parts by herself, and the suspension bridge she chose is a river between two mountains, so the mountain part is indispensable.

She is going to use the flower clay used in the flower shop to make the mountains on both sides, and small pieces of flower clay are easy to buy, but if she wants to follow the expected size, the height of the flower clay on both sides can be half a meter, so she can only go wholesale.

Originally, she wanted to use a toothpick to make a whole bridge, but it was clear that the large model was a bit difficult for herself to use a toothpick, and it was also very wasteful glue.

Therefore, toothpicks were used to simulate the detailed steel frame structure under the bridge deck, which was still made of whole pieces of wood.

Li Jiayin also thought about this material, a material that may not be common in ordinary life, but will be used in decoration - plywood.

As the name suggests, plywood is actually a type of plywood that is glued together in three layers of thin wood in different grain directions, and was used to make light aircraft in the 19th century.

Plywood was once secreted in the furniture market, but then gradually eliminated by the market because of the formaldehyde content of the glue used, and is now used as an auxiliary material for construction and decoration, such as making some interior decoration small objects in small batches.

As for how Li Jiayin could have thought of this material, it can only be said that life is not easy, she has sold furniture.

She is a person who is already a little too lazy to talk to people to sell furniture, but you can imagine how poor she was back then.

Plywood is a material that is generally used in large pieces, and she does not use so much to make bridge decks, and it is wasteful to buy the whole piece.

However, at this point in time, domestic online shopping has begun to develop, Li Jiayin searched for two days, and finally found a store willing to cut it for her and then deliver it under the condition of adding money.

The part of the bridge deck is roughly like this, and the rest is the part of the overhang, Li Jiayin calculated his own money, or decided not to be stingy, buy a thin steel chain to make the main chain, and use thin stainless steel wire to make the beam.

Originally, the two towers erected in the mountains were also prepared to be made of steel structures, but this has involved the problem of welding and steel structure casting customization, and it is difficult to find people to take orders without leaving the school, so this idea can only be abandoned.

In the end, she was going to use solid wood to make the tower pillars, but she couldn't ask the boss to help cut it, so she had to do it herself.

To this end, she also bought additional saws and punching things, as if she was a wholesaler who came out of the hardware market.

The things she has to do are big, and it is naturally impossible for her to completely fit them into the desk, so the clay, solid wood boards, and plywood boards she bought are naturally placed at the back of the classroom closer to her seat.

As a result, more than one teacher ridiculed her 'belongings'.

In the words of the physics teacher, No. 8 Middle School has held many auctions before, and she has never seen such a big production as her, so she must check the price well, so as not to even recover the cost price.

The physics teacher said this in front of the other students in the class, and there were many responses immediately.

"Teacher, don't worry, Jia Ge's business acumen is also one of the best in our class, and the big production will definitely not be lost."

Li Jiayin didn't think that he would lose money, in fact, the brand of No. 8 Middle School was very good, and it was a charity sale, and everyone was quite willing to support it.

It is certain that a large thing like hers will be at a premium, that is, the degree of premium, which is certainly inferior to a small item normally.

A very simple example, it is very easy to sell a thing that costs two yuan and sells it for twenty by hand, but it is a bit difficult to sell it for two hundred at a cost of twenty, not to mention that her cost is more than two hundred, and generally speaking, there will not be too high a multiplier profit.

The students in the third class are still very enthusiastic, it's not that they didn't see that her project was too large and wanted to come over to help.

However, seeing her non-standard design drawings that probably only she understands, as well as the various tools spread out, I am a little at a loss.

Therefore, in the end, this model of the suspension bridge, which is somewhat 'bulky' compared to other students, was finally completed by Li Jiayin alone.