Actually, he could completely simplify this process by using a lathe to drill holes row by row on the clay board. They are divided into deep holes and shallow holes, with equal spacing between each pair.
A groove is chiseled between every two shallow holes, so when casting, they can be connected together to form a metal sheet with holes on both ends.
Deep holes and shallow holes are drilled on two different clay boards.
The depth of the deep hole needs to be consistent, which can be achieved by adjusting the lathe.
A slight discrepancy is not a big deal.
The distance between each pair of shallow holes should be consistent. He relies entirely on his eyes to handle this.
This makes the efficiency very low, and the finished product is also quite substandard.
While making it, he thought there was no need for the ends of the metal sheet to be round-shaped; even if it were, it wouldn't improve efficiency.
So it was changed to a square shape.
And a mold was made using sand.
