I design the strong springs and use them for the hand grip. The force range can be 4 ~ 48 Kg if use 4 springs combination. It is good for your hand training.

No support layer is needed since I add the support layer manually. Or you can use the pure spring model that the name is like 4 mm only. Please use large fill density since you don't want to destroy the spring quickly I suppose. The height will change a little after the press and release several times. I don't know how long the spring can be used. If you have some information please let me know. You are greatly appriciated. Thanks a lot.
Print Settings
Printer brand:

Anycubic
Printer:

All-metal Mega
Rafts:

No
Supports:

No
Resolution:

0.2
Infill:

100%
Filament_brand:

Polymaker Polyflex
Filament_color:

Black
Filament_material:

PLA

https://youtu.be/w7x2_oZ-nyw