Shi Da, in turn, felt embarrassed: "It's so embarrassing to celebrate the festival every time I meet the young master. You can bring whatever you need during this period. The village has packed vegetables and other things for the children! Master, you are so stupid.

Come back with me?"

Su You nodded: "It's nice here. Come here early tomorrow."

After a day of hustle and bustle, it finally calmed down. Su You found a pottery basin, filled it with briquettes, covered it with sand, put it on a charcoal fire and simmered it, preparing to refine the coke for later use.

Lying on the simple low bamboo bed, smelling the Chen Ai that Li Shuan had burned, Su You looked at the dark roof in trance.

Su Xiaomei was very happy. She leaned over and said, "Brother Xiaoyou, this is your first time to spend the night with us."

Su You smiled and said: "Actually, I quite like this kind of life. Everything is created from scratch. We use our own hands to make life slowly get better. It feels comfortable and has a sense of accomplishment, right?"

Su Xiaomei's eyes were bright: "Are all adults like this? Then when life gets better, they will get to know each other, get married, and then give birth to new children?"

Su You sighed: "Little sister, don't think too simply. There are many other people in this world."

"Some regard your self-reliance as a sign that they have managed it well; some are greedy and hope to take the wealth created by others as their own; and more, just like us before, there is no tile above, no cone below, no thinking and no thought.

A person with a skill is like a duckweed in the water. He staggers around in daily life and even relies on the state to support him. If there is a slight disturbance, it will be a disaster..."

"That's because they haven't met their brother."

"Actually, no, these people are all part of the country. If there are too many people like this, it only means that our country is sick..."

"Then wait until my brother grows up and cure it!"

"Me? You're overthinking it again. I'm just one of the people being managed, and my power is very limited."

"Brother, don't be afraid, you still have us! Then when we all grow up, we can cure it together!"

Su You was finally amused: "Hahaha, well, when we all grow up, when there are more and more people like us, we can all work together to cure it!"

The next morning, Shi Da came again and brought several sets of pulleys.

The porcelain wheel used for the pulley is threaded through an iron shaft and clamped within the Qinggang wood board. Its strength is beyond praise.

Su You directed everyone to dismantle the upper layer of a bamboo raft and pave the slide.

The slide is divided into two sections, one leads from the waterside to the woods next to the Tutu Temple, and the other leads from the woods to the lumber yard planned by Suyou.

Then Su You began to teach everyone: "We have already talked about the principle of leverage, and everyone knows why it can save power. Today we will talk about a more advanced application of this principle, pulleys and pulley blocks..."

"Look, Uncle Shi has given us two sets of pulleys. How do we assemble them into a pulley set now..."

"Now we start testing... Look, we pour water into this jar. When the water in this jar reaches a certain weight, the rope will pass through the pulley block and lift the jar filled with water on the ground..."

"Look, the jar has been slowly lifted up. Now let's compare the water on both sides and see how much difference there is..."

"Next we talk about the error issue. You see, through calculation, theoretically, only a quarter of a jar of water can be lifted to lift a jar of water, right? But why is the result not like this?"

"...Yes, Fourth Brother is right. The weight of the jar itself has been ignored by us. How to eliminate this error? Seventh Brother, tell me..."

"Very good! We just need to hang up the two empty jars first, then fill the jar on the ground with stones until the entire pulley block is just balanced, so that the weight of the two jars is offset, and then add water, with the weight of the water

Come and conduct experiments, it will be more accurate..."

"Does everyone understand the truth? Next, we will put this experimental discovery into practice and send all the large pine trees in the water to the lumber yard for stacking!"

Next, the principle of sliding friction will be explained, and everyone will discuss how to reduce sliding friction.

Next, we will explain the arithmetic sequence and calculate how to stack pine wood into several stacks. If it is divided into three piles and stacked in a triangle, how many pieces of wood should be in the bottom layer?

The next step is how to design a crane on the blackboard that is convenient for picking up and delivering wood based on the principle of levers.

After all the designs were completed, everyone started to work.

A few older children nailed big claws to the pine wood, and then hung up the big hook under the pulley box. A few children laughed and pulled the ropes beside the fixed pulley box, and easily pulled the big pine wood from the river along the slide.

Come up.

Then he switched to another set of pulleys, pulled it along the bamboo slide on the ground to a slope in the woodyard, and then pushed it down from the other side of the slope.

There were several wooden wedges nailed to the ground, and the pine wood rolled there and stopped.

Then the pine wood is stacked layer by layer. For those on the upper floors, a crane is used, which is a big pine wood as a lever, with a strong large basket at one end. After the pine wood is tied, the stones are put into the big basket, and the stones are gradually offset one by one.

The weight of the pine wood is then controlled by traction, and the pine wood is lifted to the upper level and placed.

Shi Da looked silly and happy: "It's such a big river beach. You can place it anywhere you like. Young master, this is a toss."

Su You smiled and said: "This is also an experimental process for learning engineering knowledge. Besides, stacking them neatly like this is much better than leaving them all over the river beach, isn't it?"

In the afternoon, Su You took out the coke refined in the pottery kiln, gave it to the children to grind into powder, then mixed it with iron sand, put it into a graphite crucible, and used laboratory methods to make iron.

Small output, high precision.

However, he can only be responsible for the proportions and has to be tied down to do it.

The main components of Meishan iron sand are pure iron oxide and manganese oxide, so they can be reduced with only a simple reduction reaction.

It is impossible to achieve true vacuum powder metallurgy, but by supplementing carbon powder and controlling the high reduction environment in the pottery kiln, the obtained iron and high-carbon steel are more accurately proportioned than those produced by Shi Da.

It didn't take long before high-carbon molten steel was produced.

After that, the highly reducing environment in the furnace is changed into an oxidizing environment through air blast, and the molten steel is decarburized to obtain molten iron.

Then mix low-carbon molten iron with high-carbon molten steel and adjust the proportion of carbon in the molten iron to obtain the most suitable steel.

This method has been mastered by the people of the Song Dynasty, and is the principle of the steel filling method. However, the steel filling method directly adds molten steel to iron sand, which is not so precise.

Finally, the molten steel is poured into the sand mold to obtain the cast iron part.

After struggling all afternoon, Su You got some tips.

The advantage of high manganese steel is that even castings can have extremely high hardness as long as they are heat treated properly.

The next step is heat treatment. First, normalize the iron to soften it and make it easier to polish. After grinding, it is then covered with soil and quenched to obtain a hard steel piece. Then, through tempering, part of the hardness is sacrificed to reduce the brittleness of the iron piece. Finally,

Sharpen them carefully and get several gleaming weapons.

General Shi watched the magic all day: "It's amazing, my young master!"

Su You smiled and said: "There are no forging conditions, so we have to do this. I don't know how long the chaos will last. Let's prepare a few things for self-defense first. That's it for today. Tomorrow we will continue to make plate files and knives!"

In the next two days, Su You practiced coking at night, and during the day he took Li Shuanshuo and Xiao Qi around the furnace and made a lot of things.

The plate file only requires hardness, but it is the simplest. Use a diagonal knife to draw out the cross-fine lines of high carbon steel while it is red hot, and you can get it after quenching.

Other clumsy things, such as hammers, axes, pliers, drills, and various woodworking tools, were also brought out.

The most delicate one is the saw disc of a circular saw.

In order to make the steel of the saw disc more uniform during casting, Su You used up all the beeswax stored in the Tudui Temple and made it through the lost wax method.

Ask Shi Da to send a few roller bearings, clamp the wooden rod through the bearings, turn it with a knife, and turn out a wooden shaft with extremely high roundness.

Then use wooden shafts, wooden plywood, pins, circular saw blades, bearings, and cast iron flywheels, plus work surfaces, guide rails, and wooden scales to assemble them together to form a woodworking workbench.

Using the principle of belt transmission, the bearing is connected to a large wheel, which is driven by a thick rope. A child steps up and pedals the large wheel like a bicycle, which drives the saw blade on the bearing to rotate rapidly.
Chapter completed!