I can upgrade the shelter

A prototype was completed, and naturally it needed testing. Since it was made using his father's old work clothes, Chen Xin subsequently invited his father to help with the testing.

However, Chen Xin's father wasn't satisfied with the Exoskeleton Protective Suit that Chen Xin had made.

"I can't take big steps, and I can't lift my arms. It's not suitable for work at all." Wearing the Exoskeleton Protective Suit, Chen Xin's father moved his body slightly and offered his opinion: "Besides, the helmet is made too large; it's really inconvenient."

"So many problems?" Chen Xin was a bit surprised at his father's evaluation of the finished product.

Chen Xin's father wanted to take the helmet off his head, but because of issues with the Exoskeleton's joint structure, he couldn't bend his arms more than ninety degrees, requiring Chen Xin's help to remove the helmet.

Without the helmet, Chen Xin's father said to him, "If you require help from others just to remove the helmet, how can your design not have issues? The Exoskeleton must at least ensure normal human movement without causing obstacles."

"I'll make some adjustments; it must be a problem with the joint connection structure." Chen Xin modestly listened to his father's suggestions, noting the issues himself.

Concerned about costs, Chen Xin chose a relatively simple design for the Exoskeleton's structure. But evidently, this overly makeshift design greatly compromised the flexibility of the Exoskeleton, failing to meet practical needs.

Helping his father remove the Exoskeleton, Chen Xin then asked, "Dad, how does the Protective Suit feel?"

"A bit heavy, but still manageable, somewhat like wearing a quilted jacket," Chen Xin's father said, unzipping the Protective Suit and taking it off: "Feels a bit stuffy when worn, but nothing else seems to be wrong."

"Then it seems okay, I'll work on reducing the weight and adjusting the breathability," Chen Xin noted his father's suggestions in a notebook nearby.

After removing the somewhat bulky Exoskeleton Protective Suit, Chen Xin's father said to his son, "The issues with the suit are minor; the key is the Exoskeleton. If your design is made for people to wear while working, then it must first not affect the body's flexibility.

When designing something, you first need to clarify its purpose; all design and functions should revolve around this core purpose. If your design deviates from this core purpose, then the design itself is erroneous, even if it's well-crafted, because it contradicts your original intent.

Think thoroughly on why you're designing this object: What do you want to achieve with it, and what effect are you aiming for? Is your current design focused on this core purpose?"

Having earnestly said all this, Chen Xin's father patted his son's shoulder and went to help Chen Xin's mother.

Inspired by his father's teachings, Chen Xin refocused his thoughts, carefully setting the entire Exoskeleton Protective Suit back onto the workbench, planning to make adjustments anew.

The problems mentioned by Chen Xin's father boil down to a key point: there are issues with the joint design in the Exoskeleton portion.

Movements easily achieved by human skeletal joints are not as easily realized in a mechanical Exoskeleton; the more flexible the mechanical joints, the more complex their structure becomes.

To reduce costs, Chen Xin employed swing connections for the Exoskeleton joints, allowing movement only within a certain plane, requiring collaboration among multiple joints for flexible motion.

This undoubtedly limited the range and flexibility of the Exoskeleton's joint movements.

This design works well for the lower limbs since human legs mostly perform pendulum movements, swinging back and forth without needing to split horizontally during leisure.

However, this design proved awkward for the upper limbs.

The human upper limbs, or arms, aside from the finger joints, have four main joint areas, including shoulders, elbows, wrists, and radioulnar joints.

The shoulder joint, equipped for flexion, extension, abduction, and internal-external rotation, features a spherical joint head, known as a ball-and-socket joint. Leveraging its structural advantage, the shoulder joint can flex from 0° to 180°, extend from 0° to 50°, abduct from 0° to 180°, and rotate from 0° to 90°, establishing it as one of the most flexible human joints, surpassing even the wrist in flexibility.

Chen Xin's father's complaint about being unable to raise his arms was largely due to the Exoskeleton's shoulder activity joint.

Chen Xin used two pendulum connections for the Exoskeleton's shoulder joint: one for front-back motion and the other for up-down motion, allowing arm movement within a limited range.

Yet, constrained by the structure itself and needing connection to assistive structures, this part's flexibility was limited.

The most obvious manifestation is that users cannot lift their arms higher than their shoulders, nor can they bend them backwards.

Additionally, the Exoskeleton's elbow joints, due to connection structure issues, only perform flexion and extension from 0° to 90°, significantly less than the normal arm joint range of 0° to 150°, reducing by a full 60°, forcing users to rely on others to remove the helmet.

To enhance flexibility, one must adjust the connection structure of the Exoskeleton joints, increasing their range, or adopt more complex structures for greater flexibility.

Using ball-and-socket joints as in human skeletal structure isn't impossible; however, human skeletal joints are wrapped in a layer of cartilage that regenerates constantly, enabling them to withstand joint wear.

Even so, people still suffer from joint wear due to high-intensity labor, resulting in joint strain disorders.

In machinery, replacing with ball-and-socket joints would inevitably face wear and tear challenges.

Unable to regenerate, machinery would rely on bearings and lubrication to reduce friction, or undergo replacement after severe wear, yet frequent replacement undoubtedly raises maintenance costs, contradicting Chen Xin's original goal of cost reduction.

Moreover, ordinary metal materials used in ball-and-socket joints wouldn't withstand high-intensity usage, whereas using wear-resistant high-strength materials would increase costs.

Alternatively, adding more joints to achieve greater flexibility poses maintenance difficulties, trapping Chen Xin in a seemingly endless cycle of bald-inducing dilemmas.