When people first learn the process, they naturally make mistakes and create defects. They need practical experience to improve.
Training itself also consumes fiber-optic material because people have to practice the actual manufacturing process.
So developing skilled personnel is another part of scaling production. The goal is to develop the skills required to manufacture consistently high-quality spools with as few defects as possible.
Ars Technica: What makes manufacturing a fiber-optic spool technically difficult?
Oleksiy: You need to understand a lot about the fiber itself, about the spooling process, and about what happens when the fiber unwinds from the spool during operation.
Fiber-optic cable is fragile and can be damaged or broken relatively easily. If something goes wrong during manufacturing or while the fiber is unwinding, you can damage the fiber and lose the connection.
That is why practical experience is so important. You need to practice the manufacturing process, and that can require many kilometers of fiber just for training.
The equipment used for spooling also matters. If you use low-quality equipment or the equipment is not configured properly, you can introduce more defects into the finished spool.
So both the equipment and the people operating it affect the quality of the final product.
Ars Technica: How automated is the spooling process?
Oleksiy: It depends on the type of equipment. Some systems require more manual involvement, while others are more automated.
But even with automated equipment, skilled personnel are still required. Someone has to configure the equipment correctly and understand how the process works. The way the system is set up also affects the quality of the finished product.
So automation does not remove the need for expertise.
Ars Technica: How do manufacturers test the quality of finished fiber-optic spools?
Oleksiy: There are different levels of testing. Every finished spool should be checked to make sure the optical link itself is working properly.
But if you want to ensure consistent production quality, that is not enough. You also need to take a portion of the finished spools from a production batch, install them on actual FPV drones, and fly them under real conditions.
That allows you to test not only the optical connection itself, but also whether the finished spool performs properly during an actual flight.
So every spool should undergo link testing, while some of the finished spools from each production batch should also be tested in real flights. That combination is important if you want to maintain consistent quality in production.