This is my design submission for the TinkerCAD/MMF Easter Design Challenge! My three design goals were to be able to print without supports, have an eggshell that locks together, and (of course) to be cute. I spent most of my time figuring out an eggshell design that would print without supports and latch relatively securely. I tried hinges and threads, but there were too many complications. My kids cross-threaded or broke my prototypes every time and I knew that wasn't the solution. I eventually settled on nubs that wedge in place when the two halves are twisted together.
The outside of the shell is egg-shaped, but the inside uses a more pointy “ogive” hole shape to create the cavity. This shape tapers to a point, which allows you to adhere to the 45 degree rule and avoid overhangs/sagging deposits.
The characters who live in the shells are created using mostly spheres, various banana shapes, and Christmas trees for all the facial hair. To create the damaged areas I used spheres, asteroids and terrain shapes as “holes”. Just for fun, I printed several in white so my kids can paint them :D
I hope you enjoy printing these!
This object was made in Tinkercad. tinkercad.com/things/3rQK6ilflAc