Lần in 3D đầu tiên

The printer arrived in a box heavier than expected. Dad built it on the dining table on a Friday night and told us not to touch the hot part — a rule we have not broken since.

The first thing we printed was a calibration cube. 20 millimetres on every side. It is the boring thing everyone prints first, and we did not understand why until we measured ours: 20.3 × 20.1 × 19.8. Not a cube. A slightly wrong cube.

What a wrong cube teaches you

A machine does not do what you imagine. It does what it is told, with the errors it happens to have. If we wanted to sell things later, we needed to know how wrong our machine is, and by how much, in which direction.

Ba nói: 'Máy không sai. Máy chỉ làm đúng những gì nó được bảo.'

We printed nine more cubes over the next week, adjusting one setting each time and writing the number on the side with a marker. Those nine cubes are still in a jar next to the printer. They are the first thing we show anyone who visits.