After making a set of legendary accessories, Jin took a break. Soaking in a bath at dusk was refreshing.
「Ah, we’re doing well, we managed to get several ideas afloat.」
As Jin leisurely leaked a murmur, Reiko was watching from the side.
Now Jin wanted to make a motor engine for rotational motion.
「How to make the rotational movement from foot pedals……」
At that time, an inspiration struck Jin.
「That’s it.」
「Golem Engine.」
「The idea is turning the crank shaft by incorporating the same mechanism used in a golems arms and legs to replace the pistons.」
Jin didn’t know the difference between a 2 stroke and 4 stroke engine, but he knew enough to make an engine.
「I can try to make a prototype in bronze.」
Bronze is a material commonly used because it’s easy to shape with magic. Naturally, Jin thought to make a prototype out of this.
In the end, a prototype of the Golem Engine was completed before dark. It was about 50cm tall.
「Alright, time to commission this before dinner. ……Start!」
Inside, the drive mechanism starts to move and the crankshaft turns.
「Oh, it’s turning, it’s turning.」
It was found that the speed of rotation could be increased by pouring in more mana.
「Hmm, as I thought, this is the limit.」
The limit was roughly 300 rpm. As this was going to be cranked by hand, it was unlikely to be raised above this number of revolutions.
「Reiko, can you try to stop the shaft?」
「Yes, I’ll try.」
Reiko held the 2cm diameter shaft at an output of 5%. Although the speed of rotation slowed, it didn’t stop. It finally stopped at 10% output.
「Right, thanks Reiko, the Torque (rotational force) is quite something. It could even go in a car.」
(TLSilent: double check second half of sentence.)
It remained durable.
「Since we’ve found the max rotation, it’s time for dinner. Reiko, don’t stop it but tell me if the situation gets bad.」
With that, Jin headed for the ‘Mansion’ outside. Soleil and Luna made the daily meals there.
「It’s Soleil today. She seems accustomed to it.」
(TLSilent: I think this is what it means?)
「Yes Father.」
There was wheat porridge, bread and tea. For tea, Reiko would sneak back to Kaina village in the middle of the night to take some tea leaves. The seedling would only produce drinkable tea leaves several years after being planted.
Eating wheat porridge, drinking tea and spreading marmalade on bread. Recently, a plant similar to strawberries had been found and strawberry jam was made. Thinking about the durability of the engine, Jin quickly finished dinner and went back to the laboratory.
「Oh, Father.」
「How is it?」
「Yes, it’s working without any problems.」
「Let’s see.」
The Golem Engine was too hot to touch. The piston didn’t have a heat sink, so this was only natural.
「Alright, let’s stop it.」
When Jin stopped the engine, he took it apart. This was to determine if any parts were worn out or damaged.
「Uh huh, as I thought, the damaged parts are mostly the golem parts. An Adamantium skeleton with muscle tissue made by twisting magical fibre is best.」
If you thought that the constitution was similar to Reiko’s, you wouldn’t be wrong.
「Well then, let’s get the production started. Reiko, get me some Adamantium.」
Asking Reiko to get the heavy Adamantium, Jin went to get the magic fibre and Magi Crystals on his own.
＊ ＊ ＊
「It’s finished.」
Late at night, the Golem Engine was completed. The crank and shaft, which were supported by ball bearings, was mostly made with Adamantium. The golem parts were strengthened with multiple reinforcements.
As a result the torque was increased to nearly 3 time that of the trial. Reiko only stopped the shaft after raising her output to 20%.
「Finally, I have to make gears now.」
With that, the day’s work was finished.
The next day, Jin began to seriously consider making gears. He had tried making them before but when they were put together they were stiff or loose making them useless.
Even Magi Craft Meisters had a weakness.
The Magi Craft Meister’s ability was similar to a 3-D software drawing system. By default, the basics shapes of balls, discs or cubes could be copied.
But since there wasn’t a concept of gears, as long as there wasn’t a reference, it was hard to make it perfect.
「Hmm, how exactly can I make the model.」
Jin was grumbling as he ate breakfast. Reiko was worrying at the situation.
「Father, you have to stop thinking about it during meals.」
「Oh, ah? You’re right. ……In short first divide the circumference equally……」
「Father!」
Unable to hold it in, Reiko finally scolded Jin.
「……Reiko?」
Surprised by Reiko’s yelling, Jin looked at Reiko.
「Ah, ah, a……」
Reiko herself was surprised that she yelled at Jin.
「I-I’m very sorry.」
Whoever she learned from, Reiko went into a dogeza.
「I have had an irreverent attitude to Father. Please punish me! 」
「…………」
Jin reached for Reiko. Reiko had already determined her resolution. She wouldn’t defend or do anything, when Jin’s hands touched her, she would be deconstructed in a blink of an eye.
But contrary to expectation, Jin’s hands gently stroked Reiko’s head.
「Sorry Reiko, I made you worry. It’s as you say. From now on correct me if I’m wrong.」
「……You’re not angry?」
「Why should I be mad. Reiko yelled because you were thinking of me.」
Jin said while eating the rest of breakfast.
Jin had been thinking since the morning but hadn’t come up with any good ideas. After lunch, Jin was drinking tea at the mansion. The cup in his hand was cylindrical. He fiddled around with it while thinking of gears.
「In short, I can translate a single gear into copies. With that I can make any number of identical teeth.」
Ball bearings only need to be the same weight and spherical but a gear cannot deviate even slightly.
「Father, please don’t try the impossible.」
Reiko was anxious seeing Jin suffer like this.
But Jin didn’t seem to hear it.
「…………」
Reiko came to the conclusion that it wasn’t possible to stop Jin from thinking about it. Instead it would be better to help him to get him out of this state.
Therefore, using Engineering magic, Reiko processed a wooden board that was at hand into a circular shape. Shapes of various diameters were created and placed in front of Jin.
「Hmm? This is?」
Jin noticed it and looked up.
「I was wondering if this could help Father think.」
Jin took one in his hand. Disc. When combined it made a friction drive. In order to increase friction, teeth were cut into the side of the disc.
(TLSilent: needs to be double checked.)
「First you have to think about the materials, you want a material that won’t slip……」
A thought suddenly hit Jin.
「That’s right! First of all create a linear gear……rack. Then cut the number of teeth required, round them off……done!」
「Father?」
「Ah, Reiko. Looking at the disc you made me, I thought of something. Thank you.」
Jin stroked Reiko’s head while saying so. Reiko’s narrowed eyes looked very happy.
「With this, I can probably make spur gears. If I can make spur gears, it is likely I can also make bevel gears.」
In short, because of the equal divisions of the circumference, it is easy to make, using that as a reference, harder production is possible.
「Father, it’s time for dinner.」
Reiko said,
「Hmm? It’s this time already.」
The moon was already in the sky.
「I’m starting to feel hungry as well.」
Jin stretched while saying so and went for the meal.
＊ ＊ ＊
But after dinner, Jin started thinking of a wide variety of ways to fabricate gears, very late at last came up with a method.
「Okay, you can go to sleep now. Goodnight Reiko.」
「Yes Father, goodnight.」
Relieved that Jin also went to bed, Reiko was glad to be patted by Jin today.