Colliders have weight, it's logical, but it destroys my concept.

Ok, so TL;DR kind of explaination: I have a platform on 4 wheels. I'm adding as a child object to it a big ass hammer. I've animated the hammer inside blender, created a basic SMASHING animation. When I import it inside Unity, I have it as Skinned mesh, with bones, so I had to add colliders to the bones, in order for it to have colliders. (for smashing other objects).

The problem is that whenever the hammer actually does smashing animation, the whole platform wiggles, as well as it seems to be HEAVILY affected by the hammer movement, and I can't have that. I need somehow to make the hammer's primitive colliders, to not affect the platform in any way when performing it's action, it should only have effect on the things it smashes.

Also please note: The problem is not with the collider hitting collider or anything like that. The problem lays in the weight/force/physics, some kind of force is being created upon the animation, which makes the platform all wiggly.

Any help is appreciated, thank you.