Simplicity is welcome
Not every robotics milestone needs to become a troubleshooting story. Calibrating the leader and follower was painless and surprisingly straightforward: I positioned the arms as instructed and followed the official Hugging Face SO-101 calibration guide.
The purpose of calibration is to make equivalent physical poses produce equivalent position values on the two arms. It is the bridge between a pair of assembled mechanisms and a leader–follower system that can understand corresponding motion. After the printing adjustments, careful servo placement, and the rogue cable fault, it was deeply satisfying to reach a stage that simply worked.