Will different sizes of walnuts have an impact? For example, will an oversized walnut not be able to hold or be difficult to open, and will an oversized walnut not be able to hold in it?

The first feeling is that the rotating shaft is a little fragile.

Look at the description carefully. The function of the spring is to keep it open, but the picture is a tension spring. If you want to keep it open, you need to use a torsion spring.
If you need to use a torsion spring, the torsion spring can only be installed at the rivet position. If you have the opportunity to make a real object, the real object has nothing to do with your design effect diagram.
If you need to achieve this effect, refer to the structure of the spring clamp.
There are also three nails in front of the position to break the shell, the design is also very ridiculous, only three needles, not to mention the strength, the efficiency is too low, eat a walnut, at least reuse 3~4.
The handle is too round, which seems to be operated with one hand. If a woman cannot open it with one hand, how to use it? This is round and turns on the hand. If it is stable?
To design an old product, we should improve from the original design. The so-called "those who learn from me are born, and those who are like me die", instead of all being pushed to a new one, we cannot design for the sake of design. Moreover, the cycle is too long and difficult to be recognized.

This spring position is very strange. I didn't understand how to use it.

This is not bad

Is that clip still toothed? The structure is a bit complicated.

The design is very careful