A set of mechanically aesthetic, primitive pump-driven hand drills is completed.

With this new weapon, he immediately began the arduous task of preparing materials.

He re-entered the forest and dragged back several pieces of solid, straight spruce deadwood.

He started crafting the door frame; the entrance to the shelter was made of irregular stones and logs.

He needed to make the door frame fit this irregular opening perfectly.

He leaned two sturdy log pillars against the entrance, then used a hand axe and hunting knife to gradually carve and polish them.

This was a task that tested patience and spatial imagination; he repeatedly moved the wood to the entrance for fitting, then took it down for further processing.

Once the two pillars and the top beam fit snugly against the entrance's contours, he needed to combine these three into a sturdy "U"-shaped door frame.

He used a simple mortise and tenon joint, using a hand saw to cut shallow grooves at the points of contact between the "pillars" and the "top beam" so they could interlock.

A very sturdy "U"-shaped door frame was thus formed.

Now came the critical step of creating the base for the hinge; he firmly secured the door frame pillar where the hinge would be installed into the ground.

"This hinge system doesn't need a pivot, so the door frame itself is fixed, and we need to create a structure on it that can 'catch' the hinge."

He picked up the hand saw and hand axe.

He carefully measured and marked two positions on the side of this pillar.

Then, he used the hand saw to cut two parallel saw cuts, approximately ten centimeters apart and five centimeters deep, at these positions.

Next, he switched to the hand axe, using the axe blade as a chisel to gradually remove the wood between the two saw cuts.

After over half an hour of precise operation, a perfect square groove appeared on the pillar's side.

But merely having a groove wasn't enough; he also needed a component to secure the other end of the hinge pin.

He took a solid hardwood board measuring around twenty centimeters long and ten centimeters wide; he interlocked this board like an "L"-shaped bracket into the square groove on the door post securely.

Now, this board became the "base" for securing the hinge pin.

Then Lin Yu'an carved a small hole on the board acting as the "hinge pin base," aligning this hole with where the doorpost would be placed.

With the door frame ready, he began making the door panel, which he designed to have its own hinge structure.

He chose all the door panel materials from several pieces of wood left over from previous preparations, with diameters between 5-10 centimeters.

Among them, he specifically selected two of the longest logs, which would form the edges of the door panel and also serve as the hinge's main body.

He used a hand saw to cut all the thin logs to a suitable height, leaving an extra ten centimeters at both ends for those designated as "hinge logs."

Then, he used the axe to slightly flatten both the inside and outside of each thin log to reduce gaps.

He placed these processed thin logs tightly side by side, positioning the two longer "hinge logs" on the side where the door panel would swing, forming a heavy door panel with an extended hinge part.

Now was the time to make the hinge slots on the door panel.

This design is the most ingenious and labor-saving part of the entire structure, also the moment for his new tool to shine.

He stood the door panel upright, beginning to process the two upward-extending "hinge logs," preparing to make a hollow slot.

"To create this hollow slot, the most efficient way is to first remove most of the middle material, which is the purpose of making this tool."

Then Lin Yu'an dug a hole at the top of the hinge logs with a knife, and took out the set of pump-driven hand drills.

With his left hand, he pressed the wooden handle with a deep hole against the drill rod's top, while his right hand gripped the crossbar, pressing down with force!

"Buzz—Buzz—Buzz—"

The drill rod instantly started spinning at incredible speed! He precisely controlled the drill bit, aiming it at the center of the "hinge log."

A thick blue smoke, mixed with fine wood dust and a pungent burning smell, surged out! The air was filled at once with the distinctive smell of wood burned at high temperatures.

He maintained a steady rhythm while explaining to the camera: "Its principle is using high-speed friction to generate high temperatures, carbonizing the wood fibers at the contact point. Then, the rotational force of the drill rod immediately grinds these carbonized powders and ejects them from the hole."

Scalding hot powder flew everywhere, the whole process fluidly executed, and soon, a deep round hole appeared in the center of the wood.

Then, he used the hunting knife, using the tip as a chisel, to easily break through the hole towards the outside, cleaning up the already-carbonized wood left between the hole walls.

A perfect hollow slot appeared on the "hinge log"!

He used the same method to make an identical slot on the other "hinge log."

And he drove in a stick as a supporting point at the bottom.

Lastly, he crafted a stick to serve as a hinge pin.

All the parts were ready! Now, it was finally time for the last step of installing the wooden door!

He first dragged the door panel under the "hinge pin base," and carefully aimed the hole slot on the side of the door panel at the hinge base on the door frame pillar.