Added a plug to retain the charging cable for the AirPods as the original design relied only on a friction fit. Should print without supports and slot right in.
I've printed the original model in PLA but this latest go was in PETG which was a new printing material to me. Design should work in either just fine.
Fusion 360 Workflow
I brought in the original model into a new project and converted it to a base feature. After that, I was able to create a sketch on the bottom of the dock with a profile that matched the opening for the AirPods charging cable channel. Due to the angle of the charging channel, I created an offset plane 18.5 mm up the channel off of the original sketch and created a new sketch and included the channel geometry creating a rectangle with a mid-point. I created a new sketch with a line between the mid-points of the rectangles and used that line to sweep the original sketch profile along the line. I added a taper angle of -1º the configuring the sweep to ensure a tight but no completely friction fit. I then added a rule filet to filet all the newly created edges to make it feel nicer in the hand and hopefully allow it to fit more easily in the