This is a workable Pokeball that opens and closes. It is 3" in diameter. (7.62 cm) Made it for my nephew. Enjoy!
The Squirtle in the picture is done by FLOWALISTIK, and can be found here, http://www.thingiverse.com/thing:319413
Thanks for looking,
Made using https://www.onshape.com/
I used Onshape. Its Open Source and here is the link to modify or download source files.
Feel Free to try and build it your way or follow the below instructions.
Look at all the pictures. They will help you make this pokeball.
Printing
Print the following @ 200 microns and at 15% infill unless otherwise noted.
1 "Lower Latch"
You will also need,
1 spring @ 0.185" diameter. (A pen spring will work!) (You may have to reduce the length of the spring by cutting it)
About 1" of 1.75mm diameter filament or something similar
Assemble
Assemble the button as per the pictures. You will have to glue the "latch" to the "button" so it does not slide out.
The author marked this model as their own original creation. Imported from Thingiverse.