Chapter 100

Pulling rifling by hand is really a hard work.

The quality of this manual wooden broaching machine made by Ferguson and the wood family is very good. At least when the slider is pulled, all transmission parts run stably, and the rotation of the barrel is also very stable, which is enough to show the good quality of this broaching machine.

This is a wooden broaching machine, not a real lathe made of steel. Generally speaking, this kind of thing made of wood will vibrate or even displace when it is running. But this broaching machine does not have this kind of situation, or it has, but it is extremely slight, which can't be seen by the naked eye.

No wonder, in order to maintain the stability of the broaching machine, the eight wooden feet of the broaching machine are buried in the ground

But even with such a stable broaching machine, it takes a lot of effort to really pull rifling.

For young kids like rabbit mouth and hard bone, pulling the slider twice in a row makes their arms weak. This thing is completely relying on the strength of the human body. It forcefully pulls the hook knife to cut a layer of steel from the inner wall of the barrel, and it also drives a three-stage deceleration device. Without enough strength, it can't pull the slider on the broaching machine.

For example, some of the adult men Ferguson asked for help showed their teeth that they needed a rest after pulling the slider four or five times in a row.

Stone bear also tried to pull a few times, sure enough, this work is not ordinary people can do.

Even in terms of the strength of the stone bear, he felt his arms start to ache after pulling for more than 20 times.

Fortunately, this first rifling didn't require much time, so the five or six men around the broaching machine spent a whole afternoon pulling out four rifles from the barrel.

Rifling is divided into yin and Yang rifling, male rifling is protruding, female rifling is concave.

The Yang rifling is produced in the process of pulling the Yin rifling.

Therefore, even if only four rifles are pulled out, it is actually equivalent to cutting down the inner wall of the whole barrel by about 0.15mm.

However, although it is very laborious, although it is a wooden broaching machine, it can process rifling with 0.15mm accuracy. This life in this era can only be described as "beautiful".

At least Lieutenant Ferguson was happy with the rifling.

You know, in this era, not to mention the accuracy of one tenth of a millimeter, even if it is doubled, it is also very good. Thanks to the craftsmanship of the old wood family, the quality of this broaching machine is really good.

"Boss, the rifling of this barrel is very good. It's the most beautiful rifling I've ever seen." Lieutenant Ferguson said excitedly, holding the barrel.

Stone bear nodded, "yes, the rifling of this barrel is really good, but the efficiency of this lathe is too low. Five or six of us worked hard all afternoon to make such a barrel. How many people would it take to make a barrel on a large scale? "

This made old wood a little ashamed. Second lieutenant Ferguson also opened his mouth and didn't say anything to refute.

"So, I think this broaching machine needs to be improved, at least not so hard." Stone bear said impolitely.

Although he didn't stay with stone bear for long, Ferguson is really a very smart man. He has found out some temperament characteristics of the boss who looks scary but is delicate in heart.

So, after hearing what stone bear said, Ferguson immediately brightened his eyes and asked, "boss, do you have any idea?"

Stone Bear looked at an excited Ferguson and nodded slightly.

Although stone bear was a real otaku in his previous life, he also had many hobbies, such as reading books and consulting materials. In addition, stone bear was a semi army fan.

When he checked some gun information in the previous life, he once saw a video recording the principle of rifling.

Rifling is not very impressive, but it is the soul of a gun. Shi Xiong is also curious about how rifling is pulled out, so he watched this video.

The principle of rifling introduced in the video is almost the same as that of Ferguson just now, but the equipment of others is more advanced. After all, it is a modern lathe.

However, from that video, the stone bear also got inspiration, especially when he saw the deceleration device at the bottom of the broaching machine, he didn't know how to do it. The inspiration came like diabetes insipidus

"This broaching machine is still very good, but the only disadvantage is that it consumes too much energy, and the power loss in the transmission process is too large, so we should focus on these two aspects." Stone bear pointed to the slider, pointed to the reduction device at the bottom of the broaching machine.

"Wood, since you can make this kind of speed reducer by belt, I believe you should be able to make a more labor-saving power device." Stone bear pointed to the slider and said, "for example, if we can change our thinking, instead of using the slider as the power source, we can change it into a fixed device."

This sentence makes a few people a little confused.

Stone bear shook his head, pointed to the slider position and said: "old wood, since you can make a uniform round wheel as a reducer, can you make a reducer at this position? Well, a small wheel can be placed here, and then a large wheel can be installed here. The two are connected by belts. Then when we turn the small wheel, the big wheel can follow the belt

Old wood nodded thoughtfully, "guardian, this device is not difficult to build. But when the wheel turns, how can it drive the hook knife? "

"Ha ha, this is not simple? You install a steel bar perpendicular to the big wheel on the big wheel, and then change the pull rod screw into one with eyes at both ends. In this way, one end of the pull rod screw can be inserted into the steel bar on the big wheel, while the other end is connected with the hook knife. A slight improvement is made to prevent the pull rod from being directly connected with the hook knife. Instead, a connecting and fixing device is made behind the hook knife. The hook knife is connected with this device, and the pull rod is connected with the other side of this device. "

The stone bear's hands said: "the eyes at both ends of the pull rod can move freely because they are covered in their respective connecting parts. Then when we turn the small wheel and the big wheel turns with it, the pull rod screw can complete a forward and backward movement. "

"If we set the diameter of the big wheel to be the same as the length of the barrel, then every time the big wheel rotates for a circle, we can push the pull rod screw with the hook knife to do a complete reciprocating action in the barrel..."

With stone bear's explanation and gestures, old wood and Ferguson's eyes lit up.

PS: bow to thank "mourning Wu Huaxia" 300 for its reward.