Inspired by a video featured in this group, I have finished the extension so that otto can move his head a little 45, 90 and 135 degrees, I could not achieve more travel, through the connection cables but it is a good start. compatible with version 10 and 11 of otto body. however I have a rare vibration in the servo. I leave the video for you to observe the detail. Thanks. This week if you like, I publish the stl files, with the extension. Greetings.