I made this egg piercer / pricker to enter the Easter 2024 contest.
The spring is based on an ortho-planar spring from BYU CMR. I didn't used their model's file but I eye balled it to be able to change the dimensions easily.
To build the egg pricker you need:
NOTE: Be careful with the nail when putting it in the sleeve or putting the sleeve in the bottom part of the pricker. It is press fit so it can require a certain amount of force.
I used a metal pick with a hole in it to press everything.
For those who don't know, here is the Wikipedia link.
The author marked this model as their own original creation.