"You don't have to ask." Su Chengyu laid out the sketch and told the two foremen, "Pay attention to the center of gravity of this sword must be one inch above the gauntlet." The blade of the sword should be made of good steel, and it must be strong and durable. ”

The two of them were busy jotting it down.

"There are eight hundred swords in this batch," Su Chengyu said, "Try to finish it within two months." ”

The two foremen looked at each other, and although they felt a little difficult, they nodded in response.

Su Chengyu picked up the pen and paper again and drew back and forth for a long time, but due to the limitations of painting technology, he never drew what he wanted to express.

He simply asked the two foremen to take him to the place where the clay was made, took a fist-sized piece of clay, and kneaded it into the shape of a pair of armor.

There are five parts in total, two breastplates at the front and back, left and right shoulder armor and neck guards. Each part is composed of bevels and curves, and the overall style is close to that of European half-body plate armor.

"This one is more important than the cavalry sword." Su Chengyu pointed to the clay armor in front of him, "Cavalry armor, each part is forged from a whole steel plate. ”

Chu Di and Xiong Zhong picked up the mud sample and observed it back and forth, and discussed a few words with each other, both frowning.

"The owner, if it is made into a flat shape, it may be okay," Chu Di was embarrassed, "But this crooked shape, I'm afraid it ......"

Su Chengyu was not surprised, due to the characteristics of the Eastern War, plate armor has not been popular, so in this era when the manufacturing industry is extremely dependent on experience, Daming may not really have ready-made plate armor craftsmen.

But Su Chengyu must make the plate armor right now.

The plate cavalry had an excellent defensive effect against the small-caliber firearms equipped by the Qing army.

You must know that the musketeers of the Qing army did not have such a thing as bayonets at all, and at the same time lacked the protection of spearmen. As soon as they were exposed to heavy cavalry, basically a charge would break up.

In addition, the plate cavalry also had a very big advantage against the Qing cavalry.

First of all, it is difficult for the Qing army's cavalry to threaten the plate armor. Due to the curved shape of the plate armor, it is easy to make low-speed attacking objects such as arrows slide sideways, and with a steel plate 2 to 3 mm thick, it is basically impossible to be shot through by a bow and arrow from a distance of 20 meters.

And a distance of twenty meters was a blink of an eye for cavalry.

Secondly, the plate armor cavalry had a more obvious advantage when charging against the Qing cavalry equipped with cotton armor. Cotton armor is effective against bullets and arrows, but when facing weapons such as swords and spears, only the thin piece of iron lining it plays a role, and it has little protection.

When attacking plate armor with a sword or spear, due to the superior overall structural strength of the plate armor, it is necessary to use a lot of force and a relatively vertical angle to cause damage.

And the half-armored cavalry is more mobile than the cotton-armored cavalry!

Although it may sound like cotton armor is lighter than steel plate armor, it is actually the opposite. The cotton is compacted and not light at all! A standard Qing army cotton armor weighs between 30 and 40 catties, while a three-millimeter half-body plate armor is only about 25 kilograms, and a two-millimeter one is less than 20 kilograms.

The lighter the weight, the more powerful it is. Therefore, it is foreseeable that the cavalry of the Qing army will have an embarrassing situation in which they can't fight and can't run.

Su Chengyu originally planned to build a cuirassier unit that was very popular in the eighteenth century.

However, considering that he would often have to fight with the cavalry units of the Qing army, he finally chose a half-body armor that could also defend against cold weapons. Protect the shoulders and neck, which are more susceptible to sword attacks.

So in the end he decided to form a heavy cavalry unit dressed in half-body plate armor and armed with cavalry swords and reed wheel pistols.

Among them, the cavalry sword is the easiest to make, given the dimensions, and the craftsmen of the iron yard can make it in no time. After the spring wheel pistol has high-quality steel, with the clock-making process, it should also be able to be installed quickly.

And the most troublesome is the plate armor that looks the least technical.

The most common problem in forging a piece of steel into a curved armor is to crack the steel plate, so use low-carbon steel with better ductility, and use hot forging methods to reduce the stress of the steel structure and forge the steel plate.

But mild steel is too soft to be cut with a single knife. Therefore, after molding, it is also carburized to turn it into a hard medium to high carbon steel.

Finally, quenching is carried out to improve the hardness and wear resistance of the armor, and then tempered to improve the toughness. Such a qualified plate armor can be considered to be completed.

To say that these crafts are not known to the craftsmen of the Ming Dynasty, but no one can master the entire process. Of course, Su Chengyu, a latecomer, is an exception.

He told the two foremen about the entire production process in detail, and the two of them bowed their heads for a long time and were silent, and it took a long time for Chu Di to say to Su Chengyu: "Boss, let's try it." Although I understand what you said, I dare not say that I can't make a single mistake in the whole set. ”

Xiong Zhong asked another question, "Boss, how many sets of armor did you say you want to make?" ”

"Let's make 300 sets first. More will definitely be needed in the future. ”

"Owner, according to my estimate, it will take three or four blacksmiths seven or eight days to build such a set of armor." Xiong Zhong hesitated, "These three hundred sets of armor are made, and it will take more ......than half a year to say the least."

Su Chengyu immediately thought of the Europeans' way to improve the efficiency of plate armor manufacturing, "With a hydraulic forging machine, the craftsman only needs to control the forging part. ”

"Hydraulic forging machine?"

"It's a water wheel to drive a hammer and make it strike repeatedly."

Chu Di immediately reacted, "Isn't this a water mill?" My hometown uses this thing to make rice. ”

Su Chengyu asked him to briefly explain the structure of the water mill, nodded and said, "The basic principle is similar, but the mechanical structure is more complicated. I used the ready-made water row wheel in the iron yard as the driving force, and I drew the drawings. ”

For Su Chengyu, a mechanical major, a simple hydraulic crankshaft connecting rod system could be difficult for him.

He first measured the size of the water wheel in the iron yard, roughly planned, and designed a set of transmission mechanism in only two hours. At the current speed of the water wheel, the design forging speed is about 120 times per minute.

He handed over the drawings to Chu Di, first explained in detail the meaning of the various symbols on the drawings, and then roughly talked about the principle of this set of hydraulic forging machines.

Those unbelievable but ingenious mechanical transmission parts made Chu Di dumbfounded.

He took a few drawings and looked at them several times, and couldn't help but be amazed, and his heart was greatly admired, it turned out that this young owner was actually a hidden skilled craftsman!

In order to speed up the production progress of plate armor, Su Chengyu simply asked Chanyi to find a craftsman who built a water wheel, set up two more water wheels on the river near the iron yard, and rebuilt the hydraulic grinding machine elsewhere, and all the iron yards were converted into forging yards.

He estimated that with three hydro forging machines, plus eighty or ninety craftsmen, he should be able to complete the planned three hundred sets of half-body plate armor in two or three months.