Lesson 147: The Timing. My prototype A, being the first watch project, runs on a ST36 movement, which is a close copy to ETA 6497. Asi I have disassembled and assemebled the movement a few times I have grown familiar with it. Except one part. The timing. Finally my timegrapher is here. And what would be the best way to learn to use it than to check the timing for my Prototype A watch. Check and regulate, that is. And asit is a fairly large movement, it is quite forgiving to try and regulate it. A deviation of -6 to -16 sec per day was measured. I played with the regulator and on-and-off to regulator stand and finally (with some luck, I guess) I got it to zero deviation. I am really happy about the outcome. 🐺 .