The history of human beings making cars is very long, and the most important part of the car is the wheel, in fact, the history of the wheel is longer than the overall history of the car, and the earliest wheel was gradually discovered by human beings in the labor practice of carrying things.

In primitive societies, our ancestors lived by gathering and hunting, and at the beginning, the food they could get was limited, and it was easy to bring it back with them, but with the improvement of weapons and production tools, the more things they hunted, and the difficulty of transporting them to their destinations.

So, someone came up with the idea of picking a few thick broken branches from the ground, joining them together with vines, and then placing the prey on them, grabbing two long branches with both hands and dragging them away, which was much lighter than carrying them on their shoulders.

Some people also think of using a wooden stick, carrying one end on their shoulders and the other end on the ground, and hanging the weight between the sticks and pulling it, which is also less labor-saving than carrying it by hand.

Others put two sticks side by side, tied a rope in the middle, and held one section of the two sticks in both hands, dragging the other end on the ground.

These methods of carrying were originally invented as "light skies", which were characterized by sliding on the ground with the help of sliding bars, which were still difficult to pull on the wilderness hills with few roads.

One day, when the wind was blowing, it was discovered that under the blowing of the wind, the smooth stone or log rolled faster than anything else, and this natural phenomenon gave great inspiration to people, and people used stone axes to cut off the logs, and cut a round hole in the middle of the two ends of the logs, and then put a thin stick in the hole to connect them.

So a kind of roller sled was made, and it was much lighter to haul things than the sled of the past, and then the car appeared naturally.

The above is purely modern people's speculation about the birth of the wheel, and the real situation can no longer be verified, but when it comes to Su Yan's side, almost most of the content has been overturned.

In the beginning, when the people of the snake tribe carried heavy prey, they tied the prey to a thick wooden stick, and then two people carried one end of the prey, and if the prey was smaller, it could be carried directly on the back.

After that, rattan baskets and flat poles appeared, and the people of the snake tribe and even later the dragon tribe could use rattan baskets and flat poles to carry more things at a time, but these tools were enough for the people of the dragon tribe to use.

After all, the dragon tribe lives in the jungle, and although the car can carry more things at once with less effort, even if it is not used to build a car without roads.

As for the "light prying" handling method that modern people speculate, neither the snake tribe nor the dragon tribe has appeared.

Now the dragon tribe has begun to open up roads in the jungle, the road from the dragon tribe to the copper mine has been opened up and is being leveled and repaired, most of the road from the copper mine to the salt pans has been opened up, and it will be completely opened up and leveled and repaired this summer, and these two roads will be accessible to cars at that time.

So Su Yan plans to manufacture the car, and the wheel is the most important and difficult part of the car, as long as the wheel is manufactured, and then the car as a whole is manufactured.

And the day when Su Yan planned to start manufacturing cars was the day after Ying Yang came to the Dragon Tribe as a guest.

"The gentleman said: You can't learn. Green, taken from blue, and green from blue; Ice, water for it, and cold for water. Wooden straight rope, light for the wheel, its curve in the rules, although there is violence, do not stand up, let it be. Therefore, the wood is straight when it is roped, and the gold is sharpened......"

This passage is taken from "Xunzi Persuasion", the main content of which is to persuade others to learn and the method of learning, but this passage also describes the method of making wooden wheels by the ancients.

"Wheels" are used to bake wood with fire to bend it, that is, to bend wood into wheels with fire.

Using fire to bend wood to make wheels, this method seems a bit complicated, Su Yan thought about it, and directly threw away this method, there are so many metal tools in his hands, even if he doesn't use this method, he can make wheels.

The structure of the wheel is roughly three parts: rim [ǎng], hub [gū], and spoke, the rim is the outer circle of the wheel, similar to the current outer tire, the hub is the log in the center of the wheel, which plays the role of fixed support, and the spoke is the wooden stick connected between the rim and the hub.

In fact, the structure of the wheel is very simple, the key is that many structures of the wheel are "round", and if you want to make these structures round, you can make them, but it is more energy-consuming.

Before manufacturing the wheel, Su Yan had to design the wheel on the animal skin, and finally three graphics appeared on the animal skin, one is the wheel as a whole, and the other three are the rim, hub, and spoke of the wheel.

After drawing the drawings, Su Yan recruited two carpenters and four carpenter apprentices to try to make wheels together.

The carpenter and the apprentice are all adult male clansmen, the apprentices are a little younger, they belong to the weaker people among their peers, so Su Yan transferred them to learn carpenter's work, a total of five carpenters, each with two apprentices, and their fifteen people will almost account for one-twentieth of all adult male clansmen in the Dragon Tribe, if necessary, Su Yan will also expand the size of the carpenter team.

Choose the right wood, bring in a variety of metal tools, and the wheel making begins.

First make the wheel, choose a piece of wood for a little processing, and then take a ruler and two copper bars made of a simple compass to make a circle, first make the general shape of the wheel, and then polish, polishing is a waste of time, Su Yan used a ruler to determine the position structure, and the grinding work was handed over to the carpenter or their apprentice to do.

Two carpenters and their apprentices were busy polishing a wheel, and there were some mistakes in the process, but they were able to bear it and continue the process.

The next step is to punch holes in the hubs, the main purpose of which is to install the spokes.

The installation of the spokes is relatively simple, but the production of the spokes is somewhat difficult, the need to make each spokes basically consistent, there is no mechanical machine tool to assist processing, this is a very difficult thing, the machining is good, nothing more than mass production, for pure hand-made, the carpenter's technical level is very important.

The carpenters of the Dragon Tribe have only appeared for a year, even if they have done some carpentry work before, their carpenter skills will not be very high, but fortunately, Su Yan did not want to make the wheels perfectly, and they were worse at the beginning, and they could barely use it.

It took three days for two carpenters to produce a set of fourteen spokes, and the sizes of these spokes were more or less different.

After the spokes are made, all that remains is the rim, which is relatively difficult to make, because once the rim is not done, the whole wheel rotates unevenly, high and low, making the wheel more susceptible to damage.

A set of rims is made up of seven identical parts, which together form a circle, and this rim can be bent by fire in wood, which is more skillful and will be scrapped if you are not careful, on the contrary, it is simpler to use metal tools.

Soon, all three parts of the wheel were made and were about to be assembled into a wheel.