I was looking to build a nutcracker for the upcoming season. Quickly I decided for the screw type (less prone to "overcracking" the nut) Target object should be walnuts. I wanted the cup to be closed at one end in order to catch the finer debris an I also wanted to use a trapezoidal thread for the screw. Since I was unable to find a proper design on Thingiverse I created one. I opted for the "Hex" design style, maybe I will even print some spanners to use the cracker with in order for the cracker to be useable for my Kids.

If you plan to realize it in two colors I would recommend to actually print one set per color and the after you have broken in the threads mix the two.