A walnut themed nutcracker.

print the walnut with the nut entry hole facing up, supports needed.

Included is a modifier object to be placed at the "bowl" where the nut gets held for cracking (it should go in the right place if they are both added together, at least it seems to work in orca). You can then bump up the walls to 7 or 8 for that section to create a good solid loop around where the nut is held.