Under the stimulation of Marin's reward, Da Vinci and his craftsman team worked overtime to develop spring steel. In particular, Da Vinci, in order to get Marin's support, also worked very hard to get Lisa's marriage.

Finally, Da Vinci and the craftsmen developed a spring steel with a little flaw...

The so-called shortcomings are because the 65Mn ordinary spring steel they made lacks chromium-nickel components. Although the content of these two elements requires very little, it still has a little impact on the quality. Moreover, other components, such as manganese, silicon, copper, etc., are all present.

But in order to control the ratio required by Marin, it was very troublesome. Manganese naturally used the manganese ore that Marin sent to Venice to buy, so copper was easier to do. But silicon and Da Vinci didn't know much about what silicon was. So Marin simply asked him to add high-purity quartz sand to the steelmaking crucible. Then, he calculated the formula and told him the ratio of manganese content in the manganese ore and the proportion of silicon elements in the quartz sand.

In this way, Da Vinci and others finally created a slightly flawed (without chromium nickel) spring steel. Then, they encountered troubles in the quenching stage.

The craftsmen of this era were basically accustomed to water quenching. Water quenching made the spring steel harder, but it was also more brittle, affecting the spring's elasticity.

In the end, Marin suggested that they use oil to quench it. Just so, the whaling ship hunted a small whale and brought back a lot of whale oil. So Marin asked them to try to quench it with whale oil. Then, the spring steel tried it successfully.

In fact, Marin remembers that special steel quenching was a very profound science in later generations. In addition to water quenching and oil quenching, various medicines will also be added to the quenching liquid to enhance the performance of the steel.

But Marin obviously does not understand the quenching process, only knows about water quenching and oil quenching, as well as dual medium quenching that mixes water quenching and oil quenching. However, dual medium quenching is very troublesome to study, and what he wants is not a high-end spring, so he simply uses oil quenching.

Because of the lack of chromium-nickel elements and the technology is not as good as modern, Marin guessed that this No. 65 spring steel was inferior to modern. Therefore, after winding out a very thick automotive spring, it found that its bearing capacity was limited.

Marin had never driven a car in his previous life, but there was a spring shock absorber on the wheels of an electric car with a pedal. The principle is very simple, it is to cover a thicker spiral spring on the outside of a steel barrel similar to an air cylinder.

When pressure is transmitted on the frame, the "air cylinder handle" will transfer the pressure to the spring. The spring begins to deform, but because the spring is restricted by this steel cylinder similar to the air cylinder, it will not undergo horizontal deformation, but will only deform longitudinally.

When the spring deforms, the pressure transmitted from the frame is fully offset, which greatly reduces the vibration of the body. Marin directed the craftsmen to build four spring shock absorbers, which are installed between the frame and the wheels of a four-wheeled carriage, and conducted tests.

It turned out that the largest model of spring shock absorbers they could make, combined with four, can only bear a maximum weight of 1.5 tons of carriages. No matter how large the weight is, the springs will easily be crushed. This ability to withstand can be used in small-displacement private cars in later generations. Smaller private cars cannot be used.

But in this era, the weight of the four-wheeled carriage was not large. Generally, the closed carriage with two people weighed no more than 1 ton. Only those carrying several people, like the British gold carriage, can weigh 3 ton. Of course, that is because the carriage was too rich. Not only did it have a large space, but it also used a large amount of dense gold, resulting in the weight of the carriage exceeding 3 ton.

Generally, the weight of a two-seater carriage, even if the carriage is covered with steel plates and the passengers is added, the weight will not exceed 1.5 tons. So, Marin immediately ordered the craftsmen to create a two-seater carriage with steel plate protection and glass windows (can also squeeze 3 people), and control the weight of the carriage (including 3 passengers) to within 1.5 tons, and install a spring shock absorber.

After testing, the new carriage has very good shock absorption performance (compared to a carriage without shock absorbers), and it is extremely comfortable to ride. With the ball bearings I made before, the new carriage is simply very comfortable.

So Marin invited Angela, her mother-in-law and Ferris to ride. The three women were extremely surprised after riding in this carriage with good shock absorption performance.

Then, Angela once again opened up her enthusiasm for riding in a carriage and parades everywhere. You should know that before, riding in a carriage without shock absorbers made people bumpy every time. Now with shock absorbers, the carriage should not be too comfortable.

The ancients talked about the hard work of horses and horses, but modern people actually can't deeply understand it. Because modern vehicles all have shock absorbers. Modern people take long-distance buses, many people actually fall asleep comfortably along the way.

But if you try to switch to an ancient carriage? That's a bumpy ride. Maybe you were just asleep and suddenly had a violent bump, which suddenly woke you up and made you feel extremely uncomfortable.

Moreover, there were no flat cement and asphalt roads in ancient times, and most roads were rugged and uneven. Without shock absorbers, they could spit out all the overnight meals.

Therefore, in ancient times, every time I rode a carriage, it was a very painful thing, especially for people with weak constitutions. Even young men like Marin were not used to riding a carriage. Every time I went for a long trip, Marin rode a horse. Although it was bumpy, as long as I mastered the skills and adjusted my body according to the rhythm of the horse, it was not as uncomfortable as a carriage. Only those who could not ride a horse would sit stiffly on the saddle and would feel uncomfortable.

When Angela and her daughter drove back and forth from Orich to Emden in a new carriage, Angela excitedly told Marin that she had fallen asleep comfortably in the carriage.

Marin actually didn't agree (When did my brother take a long-distance bus and don't sleep in his previous life?), but on the surface, he still showed a surprised expression according to Angela's expectations...

In fact, if Marin was not for safety considerations and had added steel plate protection outside to prevent assassination, there would be no problem with using convertible mode or using wooden board body, and the carriage would be equipped with four strong men.

Then, Marin asked the craftsmen to make several spring shock absorbers and hit several other carriages. However, thicker shock absorbers are difficult to wind and process. During the processing process, even the most skilled craftsmen are prone to waste. Therefore, this kind of spring is destined to be produced without energy.

Moreover, because the spring bearing capacity is limited, it cannot be applied to cargo carts. Because the weight of the cart carts often exceeds 1.5 tons. Even if the shock absorber spring is installed, it is easily crushed.

However, Marin made a shock absorbing spring not to transport goods, but to allow the nobles to enjoy it. Therefore, all members of the Hoffman family got a shock absorbing carriage for easy travel.

Then, Schwartz, Frenzberg and Karnkoler brothers, as well as the homes of important officials in the country such as Jeffrey, also received shock-absorbing carriages rewarded by Marin.

For a time, shock-absorbing carriages became the best choice for the nobles of the East Friesland country. Because it was so comfortable to ride shock-absorbing carriages. Many noble families began to ride in horse-drawn carriages, visiting each other, and even having a gathering of ladies. Of course, it also means showing off their own carriages.

For example, some families who receive Marin rewards often run to the homes of good sisters who are not rewarded with shock-absorbing carriages, and invite the good sisters to ride in the comfortable shock-absorbing carriages. Then, they enjoy the envious and jealous eyes of the good sisters.

The most important thing is that others can’t imitate the shock absorber. Some blacksmiths did start to imitate the shock absorber of Marin and made springs. However, they were springs wrapped with ordinary iron, not even steel. Then, those counterfeit shock absorber carriages had good results in the first few times. After using it a few times, the springs deformed or directly broke, almost causing serious accidents. The deformed springs could not continue to provide shock absorber functions. Therefore, counterfeit shock absorber carriages quickly withdrew from the market...

Marin's carriage is not only of good quality, but Marin also marked the maximum load weight on each carriage. Because the maximum weight of the carriage cannot exceed 1.5 tons. Therefore, after each carriage is sent out, Marin will use 1.5 tons to subtract the weight of the carriage carriage and mark the maximum load weight. Warn users not to overload, otherwise there will be problems with the shock absorber. Moreover, because the spring is not rust-proof, it usually requires more oil to protect it. Once the spring is rusted, it needs to be replaced in time. Otherwise, the rusted spring steel will easily break...
Chapter completed!