Li Jing took his little sister today to participate in the cutting ceremony of the first drilling machine and boring machine of the Ming Dynasty in the Li family's secret machinery base in Nanshan Pass, Chaishan.

In order to use water power to drive the machine tools, a small reservoir and concrete arch dam were built at the foot of Mt. Shiba with a drop of 15 meters. At present, the first batch of artillery that Li Jing is preparing to manufacture is mainly imitation of Napoleonic guns. The casting of the barrel was completed at the base of Nanao Island, and the copper pillar was cast in bronze, and then transported by ship to the Meihua dock for drilling and boring machine finishing, so that the inner wall of the smoothbore gun was smooth with high precision. At present, there are three main models of infantry artillery.

3-pounder gun

Range: 365 m;

Caliber: 74mm;

Barrel length: 0.65 m;

Rate of fire: 2 rounds / min

6-POUNDER (2.54KG) FIELD GUN (THE SO-CALLED "LITTLE NAPOLEON"):

Caliber 93mm

Tube length 1.52 m (16.3 times diameter)

The gun weighed 389 kg

Maximum firing range 1392 meters

12-pounder (5.44 kg) field gun (the so-called "Great Napoleon"):

Barrel length 66 inches (1.676 m 14.3 times caliber)

Caliber 117mm

The barrel weighs 1227 lbs (556.57 kg)

Left and right wheels 57" (1.45 m) diameter

Full weight (gun body, gun carriage plus wheels)

Weighs 2445 lbs (1109 kg)

The full gun combination (the whole gun plus the front trailer and the attached ammunition box) weighs 3,865 pounds (about 1,750 kg)

The firing range is 1911 meters at an angle of 10°

Advantages: The M1857 12-pounder Napoleon gun, for example, is cast from bronze rather than iron, so it is extremely strong and able to withstand the blast force of a heavy charge or a double charge without breaking. Propelled by a standard 1.13 kg (2.5 pound) firing charge, the Napoleon was able to accurately project a standard twelve-pounder shell at a muzzle velocity of 1440 ft/s (439 m/s) at an angle of 5° to a distance of 1480m, or a staggering 10 m at an angle of 1911.

Disadvantages: Although the bronze bore is quite heavy (so that it can be strong enough), the weight of the entire gun is large, which makes it very difficult to maneuver.

Due to the need to manufacture weapons, hydraulically driven barrel boring machines appeared already in the 15th century. After J. Watt obtained the patent for the practical steam engine in 1769, the machining accuracy of the cylinder became a key issue for the steam engine.

In 1774, the Englishman J. Wilkinson invented the gun barrel boring machine, which was used to machine cylinder blocks for the Watt steam engine the following year. In 1776 he built a more accurate cylinder boring machine.

Around 1880, the production of horizontal boring machines with front and rear columns and tables began in Germany. In order to adapt to the processing of extra-large and extra-heavy workpieces, a floor boring machine was developed in the 30s of the 20th century.

What Li Jing saw this time was a horizontal barrel boring machine, the cutter can be replaced, and it can be applied to the processing of the gun chamber of different caliber guns, and the cylinder of Li Jing's steam engine will also be processed with this in the future.

Due to the limitations of smelting technology, the barrel of a simply cast cannon has inevitable trachoma and bubbles. Unable to withstand continuous fire, it is necessary to rest every once in a while to cool down, and after firing 600 rounds of iron cannons and about 100 rounds of copper cannons, it is no longer very useful. If you want to exclude trachoma and bubbles. It is necessary to forge the blank and forge it into a forging blank that meets the requirements according to the drawings and specifications. After the blank is burned red, the trachoma and bubbles are squeezed out during the continuous forging process.

After the barrel is forged, the inner chamber of the barrel is processed and formed, and the processing method is to drill a hole with a large drilling machine equipped with an extra-long drill bit, and then go to the hammer machine to gradually hammer the hole into shape.

This belongs to the "deep hole processing" that is very difficult to process, in the process of deep hole processing, the operator can not directly observe the cutting and other processes, and at the same time it is necessary to ensure that the processing must achieve a high degree of accuracy, and the slender pipe fittings that burn red and become soft are also prone to bending and deformation during the processing process. Therefore, it is extremely difficult to process.

Because the quality of the bore processing of the barrel is closely related to the shooting accuracy, life and safety of the whole gun. Therefore, the dimensional tolerance, bending, roughness and other aspects of the processed are extremely high. After the rough machining is completed, the barrel body should be subjected to some necessary technological treatments, such as surface treatment, heat treatment, non-destructive testing, etc.

The barrel is considered to be one of the most difficult "long tubes" to machine, especially in the process of forming the bore of the barrel. The machining method of the bore hole of the body tube is to first drill a hole with a large drilling machine equipped with an extra-long drill bit: then go to the boring machine to gradually boring the hole into shape. In machining, hole machining with an aspect ratio greater than 10 or more is generally called deep hole machining.

The length-to-diameter ratios of large and small Napoleonic guns were around 16.3 and 14.3, respectively. It is a typical deep hole machining. These bronze cylindrical barrel blanks, after being cast and formed on Nanao Island, are also burned red here, forged with a hydraulic forging hammer, and then placed on a drilling machine for drilling, and then put on a boring machine for processing.

Today, these two machine tools are mainly used to process artillery, and by changing the tools and drill bits, it is possible to process three army guns, three-pound guns, six-pounder guns, and twelve-pounder guns, as well as twenty-four and thirty-six-pounder naval guns. However, the weight of the naval guns was too great to be moved by manpower, so it could not be forged, and could only be cast and molded at one time. It is then drilled and bored for processing. The weight of the thirty-six-pounder gun was about three tons. Manpower can't turn at all, and it can't be forged. A few hundred kilograms of Napoleonic barrels could be moved by simple mechanical rotation and could barely be processed.

After the ribbon cutting, the performance was tested on the spot, and this time the three-pounder gun was chosen, with a caliber of about 74 mm.

Three-pounder guns were very lightweight, and they could be quickly brought into battle in battle, firing at enemy armies or forts. 3-pounder gun range: 365 m; Caliber: 74mm; Barrel length: 0.65 m; During the American Revolutionary War (1776-1781), skilled soldiers could fire a 3-pounder cannon once in 30 seconds.

The steps are also simple. The first step is to use a worm (spiral iron) to clean the gunpowder residue in the gun chamber. The second step is to wash the chamber twice with a wet sponge to prevent sparks from igniting the next round of ammunition. The third step is to load the ammunition and use the ramrod to push the ammunition to the bottom of the gun breech. The fourth step is to use a needle to drill a hole through the fire transmission hole to pierce the gunpowder bag. The fifth step is to fill the fuse in the punctured powder bag. Step 6: Use the ignition rope to light the fuse after aiming.

Since the weight of the barrel blank is only 180 kilograms, several people can use a simple lever machinery to rotate and process, four people easily use fire tongs to clamp the red-hot blank, under the hydraulic forging hammer gradually hammer to form, and then put it on the drilling machine, fix it, and start the hydraulic turbine at the same time, drive the drill bit to start drilling.

After the drilling is completed, a few more people continue to use fixtures to clamp and put it on the boring machine to finish the breech, so as to maintain the absolute roundness and smoothness that can be achieved in this era of the breech. In about an hour, a processed cannon barrel was placed in front of Li Jing to cool. Li Jing felt that the three-pound cannon was the easiest to process, so he decided to give priority to the production of a batch and transport it to Yingkou, which should be in time for the Shenyang War.

After making the three-pounder cannon barrel, he tried to produce an imitation brown bass flintlock pistol, which was much easier, Wang Laosan personally went into battle, and used tongs to clamp this one-meter-five-long, 20 mm diameter steel column after being forged with a hydraulic forging hammer, and then placed on the drilling machine to be fixed, and the drilling machine was replaced with a small drill bit, and then transferred to the boring machine, and continued to process the inner wall. Half an hour, Wang Laosan put the processed barrel in front of Li Jing.