OnCollisionEnter not working?

I know this question is asked a lot, and I've had this problem before ,but nothing I can find solves my problem. I have a simple script, so that when an object (tree) is hit with an axe, it will drop a piece of wood. However, It doesn't ever even count as getting hit. The axe is attached to the FPS Controller, and i'm wondering if that's where my issue stems from. I've also tried OnTriggerEnter, doesn't work. I've had the tree with a rigidbody, every piece with a rigid body, the axe and every component with a rigid body, "is trigger" on and off, but nothing works. What should I do? Here's my script:

 // Use this for initialization
 void Start () {
 Debug.Log("test");
 }
 
 // Update is called once per frame
 void Update () {
     if(woodcounter >= 15)
         {
         Instantiate(wood, new Vector3(a, 0.5f, a), Quaternion.identity);
         a++;
         woodcounter = 0;
         
     }
 }
 public GameObject wood;
 public float a;
 public float woodcounter;
 void OnCollsionEnter(Collision other)
 {
     Debug.Log("1");
     if(other.gameObject.tag == "axe")
     {
         Debug.Log("2");
         woodcounter++;
     }
 }

}

Thanks for the help! This script is attached to the tree, in case that matters. Both the axe and tree are under an empty game object that holds all the child parts, but I don't think that should matter. And yes, i've tried changing the script so that it is on all parts the tree.

Thanks! :)