3d printing gets funny and difficult when you try to do mechanical movement in one-step printed object. Besides if you split the model in two colors the results will improve but also complexity will do because when there is two colors on same surface(for example emoji face) to avoid mixing colors you have to put holes(eyes and mouth) in model color that has not to be printed.
Step 1: Emoji Keychain for 3d Printing of One or Two Colors With Mechanical Movement
We have tried to put together these challenges on this design.
-when you print it you will see there is a mechanical movement of inner emoji disc
-also you can take the benefit of two colors design if you have 2 extrusor 3d printer
The emoji keychain have focused on simplicity and to make something funny . With it you can show your mood to others or for example to suggest waiter an aditional beverage in a pub ;-)
Step 2: One Color 3d Print
you can use this file to print with one single extrusor