Kays Translations

Chapter 146: Magic Car Creation – Step 1

The cart, gradually accelerating with a steady breeze from the wind manipulation orb, reached a brisk walking pace and then settled into a steady speed.

Eto, after confirming this, increased the supply of magic power by one notch. As a result, the wind felt on the cheeks strengthened, and the cart accelerated a beat behind.

When the cart reached a jog-like speed and passed through the center of the training ground, Eto stopped the supply of magic power.

Losing its power source, the cart rapidly decelerated and eventually came to a stop.

As this was just the first step of the prototype, brakes and steering were not yet installed, so a leisurely deceleration was necessary.

“At least it moved.”

“Yeah. If the cart couldn’t move in this state, it would have been game over…”

Isamu breathed a sigh of relief at Eto’s words.

“How strong was the wind when it accelerated earlier?”

“Just a bit less than half strength.”

“I see, about half strength… Let’s start by confirming how heavy we can make it with this simplest method.”

“Right. It’s better to confirm the limits first before trying various modifications.”

They began by exploring the limits with the simplest method. If satisfactory output could be obtained this way, it would undoubtedly be the best choice.

Then, Isamu and the others repeated the process of loading removed cart parts and testing. They piled them on the base without assembling them, just to determine the weight.

After spending another day testing the weight limit, they found that with all the parts loaded plus one person as cargo, the cart could still run with just enough cargo.

“We couldn’t load much cargo, but it’s significant that we confirmed this cart can carry a person even in its current state.”

“Yeah. This one was tailored for nobles, so it’s heavy with a lot of decorations. It’ll be lighter if we make a new one for the wind manipulation orb.”

“Right. We shouldn’t make it look too shabby, but we’ll use lightweight monster materials for decoration in the end.”

“That sounds good. Since the Bastet series also uses solid beetles, it should work out just fine.”

Feeling relieved that it seemed to be reaching a practical level, Isamu began designing based on the experimental results.

The first thing they did was to enlarge the windmill, the power source.

The force from wind pressure increases proportionally with the size of the area it hits. Naturally, the larger it is, the more wind it receives, making it stronger.

However, since it had to be attached directly to the axle, extending it too much vertically would require the wheels to be enlarged and the cart to become too tall.

Therefore, they decided to limit the extension in the vertical direction and extend it horizontally instead.

The cart used for weight testing was of the standard size in this world, Ethersia, with a width of about 2 meters. They extended it about 50 centimeters horizontally and extended the width of the windmill accordingly.

Behind that, they placed the wind manipulation orb, the power source.

They also decided to use mithril for the windmill after much consideration. Although it was expensive, it was lighter and more durable than iron used in experiments, so they boldly chose mithril for the crucial windmill part of the magic car.

The windmill they created was then attached to the axle, made of black iron harder and lighter than iron.

They attached rear wheels with a diameter of about 1.5 meters, larger than the standard ones, to the axle.

Making them any larger would be difficult and would raise the cart’s height too much.

They attached these rear wheels to the underside of the cart, raising only the upper part of the rear wheels to prevent interference while considering suspension compression and extension.

One of the significant concerns was that with the windmill attached to the axle, the minimum ground clearance would be considerably lower than that of a regular cart.

However, it still had about 25 centimeters, higher than the normal ground clearance of an SUV in Japan, and since it would mainly run on roads, they decided to overlook it for now.

To address this, they would need to separate the power source and the axle and transmit power using gears or pulleys, which would not only be labor-intensive but also unavoidable power loss.

They decided to leave this area for now and look forward to it along with torque increase due to the gearbox.

As for the front wheels, they used standard 1-meter wheels.

Unlike carts, which can’t turn without adjusting the angle of the front wheels, they needed to incorporate a steering mechanism.

Compared to a land yacht, the vehicle is heavier and has two front wheels instead of one, so we were unsure how to design the mechanism.

After trying several methods, including extending front forks like those on a bicycle to each of the front wheels and operating them, they settled on a combination of circular and linear gears.

This unintentionally led to the adoption of what was called the rack and pinion type, a mechanism also used in modern car steering systems.

However, what Isamu made was far simpler compared to modern ones, with no power steering functions included. Isamu didn’t even have knowledge that rack and pinion systems were used in modern cars; it was just one of the methods he vaguely remembered for converting rotary motion into linear motion, and it seemed simple and sturdy. Also, as there might be more opportunities to use gears in the future, he adopted it as a rehearsal for that purpose…

With two out of the three elements of a car—moving and turning—implemented, they decided to test it again.

Though “stopping” was theoretically the most important for safety, they couldn’t determine the required speed and braking force at the moment, so they decided to verify these aspects first.

For safety, they used cart attachments installed as insurance to move to the usual training ground.

It might seem contradictory, but it would be reckless to run on public roads without brakes.

Since Isamu and Eto had already confirmed that the cart could move even when they were on board in the backyard of the laboratory, they immediately boarded and began the test run.

“Since it moved with less than half the wind power, let’s start from there.”

“Got it. Since there are no brakes, let’s start by running slowly and checking if we can turn properly.”

The two, who had become quite accustomed to the magic car, started a test run while exchanging light conversation.

Gradually increasing the output and pouring in magic power up to just under half the maximum, the magic car started moving with a creaking sound.

“Hmm, I really need to do something about the bearings… If I could make ball bearings, that would be the best, but it’s still too difficult…”

Isamu muttered to himself upon hearing the sound.

The bearings, which were essential for using the wheels, were made by combining two pieces of smoothly polished semicircular black iron and applying slippery shark grease instead of grease.

These bearings should reduce energy loss more than the standard bearings in this world of Ethersia, but there was still room for improvement.

By the way, up until now, since it was being pulled by a horse, there was no need to transmit power to the wheels, and the axle itself did not rotate, only the wheels did in a system where they rotated. 

This time, to rotate the wheels and use them as the power source, the system was changed so that the axle and wheels are fixed, and the wheels are turned by turning the axle. 

Would it be easier to understand if you imagine the wheels of a certain four-wheel drive toy that adults get obsessed with, even though it’s for kids? 

Leaving that aside,

When the magic car, which had started moving, accelerated to a leisurely pace akin to casually pedaling a mama-chari(a Japanese-style bicycle for women), the supply of magic power was reduced. 

It requires more significant force to move something from a standstill than to keep something that is already moving in motion, so if it continues to run with the same magic power, it accelerates more than expected. 

How much to reduce the magic power to maintain the current speed would require gaining a sense through accumulated experience.

As the edge of the training ground approached at the leisurely pace of a mama-chari, the handle was turned to bend the magic car.

“Hmm, the handle feels heavy without power steering… Well, since we won’t be going too fast, I think we’ll manage somehow. I wonder if I can lighten it by adjusting the gear ratio.”

Isamu muttered while turning the handle.

For someone accustomed to modern cars, the primitive steering mechanism without power assistance feels heavy.

Adjusting the gear ratio in the future seems like a good idea to make it easier to turn.

“Also, I’d like to do something about this kickback, but it might be a bit difficult…”

Another challenge for the handle is kickback, which conveys the condition of the road surface to the handle.

In modern cars, this would be dampened unless under extreme circumstances, but with the current mechanism, it is transmitted almost directly.

However, Isamu has no knowledge of how to dampen it, so trial and error with various approaches will be necessary to improve it.

Turning the heavy and vibrating handle to the left, the vehicle began to turn left accordingly.

Feeling a slightly stronger response, Isamu memorized how much to turn the handle to achieve a certain degree of turn.

After making a clean arc and completing a 180-degree turn, the supply of magic power was slightly increased for a slight acceleration, then the handle was turned again at the opposite end to rotate the vehicle.

Repeating this process, they explored the limit of speed at which they could turn without having to turn the handle all the way.

After about an hour of test runs, they found that they could comfortably drive at a cruising speed similar to that of a mama-chari, around 15 kilometers per hour.

Numerically, it might not seem very fast at first glance, but the cruising speed of a horse-drawn carriage in this world of Ethersia is around 6 to 8 kilometers per hour.

Compared to that, it’s almost twice the speed, and if the driver and passengers are okay, they can continue running without a break. Also, there’s no need to worry about heat like with internal combustion engines.

Considering all these factors, it could be considered quite groundbreaking.

Furthermore, if safety is overlooked, Isamu secretly calculated that up to about 20 kilometers per hour would be within the acceptable range.

“Hmm. This is more than practical enough… It’s incredible to be faster than a carriage without needing to rest.” 

Eto murmured with a sense of realization as they caught their breath after the test run.

“Yes, I think traveling will become much easier. Well, it does consume a fair amount of magic stones though…” 

Isamu also seemed satisfied with the performance of the prototype.

“Starting tomorrow, we’ll verify if it can run properly with the expected cargo load.” 

“Yes, I think it should be fine with half the magic power at this point.” 

Since wind pressure per unit area is proportional to the square of wind speed, there is still more than double the power available even with only half the power at the moment.

“Yes, if it’s just running, there shouldn’t be any problems. The real question is how long it can run on one magic stone.” 

“Even if it’s convenient, it’s hard to use if the operating cost is too high… It would be great if it had a practical fuel efficiency…”

Isamu, who wants to use it for everyday purposes, is particularly concerned about fuel efficiency.

“There’s also another concern: what to do about the brakes. Even if we don’t accelerate too much, unlike a carriage where the horse adjusts, it becomes essential on downhill slopes.” 

“Yes, inadequate brakes could lead to trouble if it accelerates uncontrollably…” 

Eto nodded in agreement.

Another concern for both of them was the brakes. While they could overlook safety to some extent, they couldn’t be too reckless.

And so, the development of the magitek car moved on to Step 2.

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