Half an hour later, the two of them came back with a piece of wood with a diameter of more than 40 centimeters and a length of more than 3 meters.

According to Chen Xu's design, the biggest problem of this simplest hand-cranked thresher is the stability of rotation, to ensure that it will not be often stuck by wheat straw after rotation, so the kinetic energy of the spindle when rotating is very large, that is to say, it must be very heavy, after rotation, it rotates at high speed under the rotation kinetic energy of the spindle itself, so as to break the shell of the wheat ear, the faster the rotor speed, the easier and cleaner the threshing.

Chen Xu asked Niu Dashi to first choose the straightest place from the wood he brought back and sawed down a wooden stake about 80 centimeters long, and then scraped the bark outside with a firewood knife, and then used a chisel to dig a small hole two inches deep on it every three inches, and the positions of the small holes were all staggered.

In fact, Chen Xu has never done carpentry before, but when he was a child, he saw a carpenter make doors, windows, tables and chairs, but after crossing over, he found that he was the best carpenter in the village.

When repairing the house, the rough tenon he designed and made according to the gourd painting scoop was affirmed by the whole village, and it was unanimously believed that the tenon not only accelerated the speed of building the house frame, but also strengthened the safety of the house.

For example, the simplest double-concave connecting tenon, which was commonplace in later generations, but the villagers were as surprised as if they had discovered a new continent, and unanimously decided to use tenons to rivet their own houses in the future.

Later, Chen Xu asked and learned that now people in the village have to go up the mountain to choose those trees with branches in just the right position to repair houses, otherwise the beams of the house will not be erected.

And with the construction of a house, Chen Xu's wooden work is getting better and better, and the knives, chisels, axes and saws are all used in a good way, although he is definitely the most lame carpenter in the later generations, but at the moment, he is the best carpenter in the crossing army.

Just when Niu Dashi was processing the center shaft of the threshing machine, Chen Xu also used a few pieces of wood with the thickness of a calf to build a simple wooden frame, one meter high and about one meter wide, and used an axe to cut out a U-shaped bracket on both sides to place the threshing spindle that Niu Dashi was making.

Then there is the main hopper, which must be sealed with wooden boards, Chen Xu calculated, about ten wooden planks are needed, so he can only pick up the copper saw again and start sawing the planks.

The day flies.

After the sun was about to set, Chen Jiang came back from the river beach with Xing'er, Chen Jiang's jumped a rattan basket, and Xing'er carried a basket of pigweed.

At sunset, a strange wooden box sits in front of the house.

Chen Xu and Niu Dashi were sweating profusely around the wooden box, and there was a huge piece of wood covered with bamboo nails inside.

"Brother, what is this?" Apricot asked in amazement as she circled around the strange box.

"This is the thresher we made!" Niu Dashi replied excitedly.

"What is the threshing machine for?" Apricot had a pair of eyes wide open.

"For harvesting wheat, you don't have to bring the ears back to dry, you can peel the wheat out of the field." Niu Dashi's eyebrows danced and said.

"Oops, great! Mother~Mother~, come and see, my brother made a threshing machine, and we don't have to pick ears of wheat back to dry anymore! Although Xing'er didn't seem to understand, she still shouted loudly.

Chen Jiang said while cooking on the fire: "Don't disturb my brother and Brother Da Shi's work, hurry up and feed the pigs, and make tea for my brother after feeding!" ”

"Huh~" Xing'er promised to hurry up and feed the pigs.

Chen Jiang's mind is simple and direct, and now she feels that no matter what her son does, she feels that it is right, because her son has become the most popular person in the village, and now wherever she goes in the village, no matter who she meets, she will happily praise Chen Xu, which makes her heart always sweet.

She also heard what Niu Dashi said just now.

Therefore, her heart is also full of anticipation.

How did this strange-looking wooden box remove the grains of wheat?

"Come on, lift the spindle down, that's pretty much it, put the spindle on and you can rotate it for a test." After Chen Xu continued to observe and measure, he used an axe to knock several places next to each other a few times, and it felt almost the same, so the two of them lifted down the huge spindle that was fifty or sixty pounds.

Next, a large square hole with a side length of 15 cm must be drilled in the center of each side of the spindle, and this hole must be used to install the shaft, and in order to ensure that this hole must be in the center of the spindle, Chen Xu used a bamboo ruler made by himself to measure repeatedly for a long time before drawing a box with a thin charcoal.

Niu Dashi has always been a passive helper, Chen Xu said that he didn't understand anything about the spindle, rotating shaft, hopper, crankshaft, but it didn't prevent him from showing enough interest in this magical thing.

It's amazing, he doesn't even know where his eldest brother learned these unbelievable things.

The square hole must be completely vertical, so as not to jump when the center of gravity is unstable when the main shaft rotates, Chen Xu is not at ease to let Niu Dashi do it, so he must complete it by himself.

In order to make the thresher strong enough, the square holes on both sides were nearly 20 centimeters long, so it was not until Chen Jiang finished dinner that the two square holes could be completed.

After dinner, drinking tea and resting for a while, Chen Xu began to make the main shaft again, using two rosewood with the thickness of a calf, one end cut into a square, and the other end trimmed into an almost regular cylinder with a knife and axe, and carefully nailed the square head into the square holes at both ends of the main shaft.

"Whew, it's good that the spindle didn't crack!" When the two reels were all nailed in, Chen Xu couldn't help but let out a long breath.

When the spindle and hopper are completed, the thresher is 90 percent complete, and the last step is to install the crank handle.

First, a convex tenon is sawed out at the cylindrical end of the spindle at the long end, and then an L-shaped wood is riveted with a square hole specially sawed back, and then punched into the bamboo nail to be stuck, and finally tied with hemp rope densely on three or four layers, and the joint of the crank and the shaft tenon is bundled like a zongzi, so that the thinnest and most stressed parts can avoid being broken too violently.

In fact, the joint part of the spindle and the hopper, as well as the tenon riveting part of the crank should be made of metal, so that it will be more wear-resistant, but unfortunately there is no such condition at the moment, and it is too late to build it in the town.

"Here, carry it up and try it!" Chen Xu dropped the hemp rope in his hand.

"Brother Xu, that's okay?" Niu Dashi was excited, and his eyes that had been standing by and watching just now did not blink, and he was full of infinite admiration for his uncle who made such a complex thing with tenons.

"Well, put it on and turn it around to see the effect!" Chen Xu nodded, and the two of them lifted the spindle with the shaft and handle and put it on the bracket of the hopper.

"Click~"

With the spindle resting firmly on the U-shaped bracket, the gap between the spindle and the two sides of the bracket is less than one centimeter, which is completely within the scope of Chen Xu's design.

Finally, an old bamboo tube was put on the handle, and the first hand-cranked artificial threshing machine in Chinese history was officially completed.