Chu Di and Xiong Zhong divided the work, one was responsible for making the parts of the hydraulic forging machine, and the other led people to try to build a set of plate armor by hand to familiarize themselves with the whole process.

As for the "simple work" of forging cavalry swords, they directly threw them to their blacksmiths, and only occasionally went to check the progress of the work.

Qiao Qian quickly bought graphite and other raw materials and returned to the iron yard. Su Chengyu simply picked up the shovel, stirred six or seven hundred catties of graphite, clay and other materials evenly, and then copied the firing process to Qiao Qian, and asked him to transport it to the porcelain kiln to fire the crucible.

Even if the crucible is lost quickly, when these hundreds of catties of raw materials are burned out, it should be enough for the iron yard to consume more than half a year.

Su Chengyu spent another whole day instructing Chu Di to make the core components of the forging machine, such as crankshafts and gear sets, and then went to the firearms workshop. As long as these core components are not wrong, the craftsman's skill in making wooden machinery should be reliable, and it is only a matter of time before the hydraulic forging machine is completed.

Lu Ning and other firearms craftsmen saw Su Chengyu coming, and they hurriedly stepped forward to pay respects, they were one of the few people in the iron yard who knew his identity. But without permission, they didn't dare to mention it to others.

Su Chengyu hurriedly asked them to get up, instructed them not to be formal in the workshop, and then asked about the trial production of the six-coin pipe.

"Your Highness......"

"Just call me the owner in the iron yard." Su Chengyu smiled. Too much etiquette at work can also be quite troublesome.

"Yes, host." Lu Ning bowed in response, then took a pipe placed on the wooden frame and handed it to Su Chengyu, "This is the pipe that was just made three days ago. Loaded with six and a half cents of buckshot and nine dollars of gunpowder, dozens of test shots, none of which exploded. ”

Su Chengyu took the octagonal iron pipe and weighed it, about seven or eight catties, because it was a trial product, the surface had not been polished, revealing the rough beauty of iron.

Without waiting for him to ask, Lu Ning pointed to another gun pipe on the gun drill frame: "The villain thinks that it will probably not be enough to use nine coins of gunpowder, so he tried to make another pipe with a slightly thinner wall." ”

Su Chengyu saw seven or eight pipes of varying thicknesses placed behind the gun drill frame, obviously these craftsmen had made a lot of attempts recently to get the finished product in his hand.

You know, these tubes are all boring by hand, and it takes two skilled craftsmen five or six days to make one.

In addition, there are more than a dozen sets of guns and machines piled up on the side, and it is obvious that as long as the guns are of a certain type, they can be installed and tried immediately.

"Oh, yes, host." Lu Ning picked up a pair of guns and pointed to the springs on it, and said excitedly, "We picked out some of the newly smelted steel ingots in the iron yard to make springs, and the spring force has increased by more than two percent compared to before." Now the firing rate of this machine is 70%. ”

Su Chengyu nodded, "The elasticity of this machine is enough for the time being." In the future, when I have time, I will teach you to make special spring steel, which has more elasticity. ”

He immediately remembered the problem he was most concerned about, and said to Lu Ning: "It seems that there is no problem with this pipe." At the current rate of your twelve masters and apprentices, how many flintlocks can you make per month? ”

Lu Ning thought for a while and said, "If you rush to work, you should be able to make about forty sticks." ”

Su Chengyu calculated in his heart, that is to say, if he wanted to make 3,000 flint hair clands within two months, he would need more than 400 skilled craftsmen!

The iron yard has recently recruited some craftsmen, but it seems that there should be no more than one hundred and twenty people, which means that even if all the craftsmen are allocated to make guns, it will take more than half a year to complete his goal of 3,000 guns.

"What's the most time-consuming step in the process?" He asked Lu Ningdao. Since there are not enough people, we have to find ways to improve efficiency.

"Naturally, it's a drill and a grinding pipe." Lu Ning pointed to the gun drill frame again, "After rolling the rough barrel with wrought iron, the inside of the barrel is extremely rough and cannot be fired.

"It is necessary to drill the inner hole of the gun tube with a small reamer one circle, and then use a thicker reamer to continue to drill to a larger one, usually four times to reamer to expand the suitable hole. This process is time-consuming, laborious, and easy to drill. Skilled craftsmen can drill to a depth of about seven inches in an hour. ”

Su Chengyu walked to the drill frame to watch, it was a wooden frame that was a head taller than him. In the upper part, there is a gun drill more than four feet long, and the drill pipe is wrapped with a bowstring, and pulling the bow back and forth can drive the drill pipe to rotate. The lower part is made of two wooden planks that hold the pipes in place.

Lu Ning explained on the side, "When grinding the pipe, one person pulls the bow, and the other person presses down the drill pipe, and the drill pipe drives the conical drill bit to go deeper into the pipe.

"During the whole process, we had to constantly remove the hose to check if it was crooked. Inexperienced craftsmen will even break two or three pipes for every gun they drill. ”

Su Chengyu frowned at this simple drill frame, first of all, the shape of this drill bit is not reasonable enough, and it is much worse than the common drill bit that has been calculated by function in later generations, in terms of efficiency and stability.

Secondly, the drill frame adopts the mode of pressing down the drill bit, and the drill bit is easy to shake left and right in the process of being pulled and rotated by the bowstring, no wonder it will often drill crookedly and cause the pipe to be wasted.

And the solution is also ready-made, and any boring machine in any small processing workshop in the future will be able to do the trick. It's just that there is no motor at the moment, so it can only be driven by manpower.

Su Chengyu asked for a pen and paper and began to draw the structural diagram of the boring machine.

This time it was much simpler than designing a hydraulic forging machine, and he had seen a lot of boring machines, so he didn't need to bother to design. Second, the single function required by this boring machine is to drill the pipe.

Therefore, all lifting mechanisms and fixtures can be omitted, and the fixed ones can not only reduce the technical requirements, but also have better stability.

Soon after, he drew a design drawing for a foot boring machine.

Lu Ning and the others were already very familiar with this kind of standard industrial drawings, and they were not surprised that His Royal Highness King Chenzhou, who was equipped with the "Qimen Dunjia Technique", could design such an extremely exquisite instrument.

Su Chengyu explained the structural principle to them, and several people found some carpenters from the iron yard, and began to make this foot boring machine.

Although the boring machine is much smaller than the hydraulic forging machine, it is more difficult to make than the former. The main reason is that the finishing ability of this era is too ordinary, and many delicate small parts may not be usable after repeated grinding and testing more than ten times.

Su Chengyu could only guide the craftsmen to process parts on the side, and from time to time to see the manufacturing of the hydraulic forging machine.

Unexpectedly, the hydraulic forging machine was going well, but Xiong Zhong, who was in charge of forging plate armor, came to Su Chengyu with a bitter face.

The reason is very simple, there is no "soft steel" in the steel ingots smelted in the iron yard.

Soft steel and hard steel are the intuitive names of low-carbon steel and high-carbon steel by the ancients. Xiong Zhong tried hundreds of steel ingots, and the softest one was also hard steel, which was difficult to forge.

Su Chengyu patted his head and was negligent! Most of the crucible steelmaking is high-carbon steel, and there are very few medium-carbon steels. Because the crucible used for steelmaking is made of graphite, and graphite is pure carbon.