Jump works but is not the same height every time i jump

i cant use gravity for starters. im trying to create a rigidbody character controller to walk on walls or rounded surfaces. I can jump but when I do its not the same every time.

also another question... I have to create a rigidbody variable in unity 5 and assign the gameobject the script is attatched to to access the already present rigidbody component attached to my gameobject. is there anyway around this.

ex.`rigidbody.velocity` doesn't show up in mono develop. if I add a rigidbody variable and assign the gameobject the script is attached to to itself then I can access it that way but its just more typing.

ex. public rigidbody character; character.velocity that shows.

anyways back to my original question. sorry. I can ask that later if I need to.

 public Rigidbody TheCharacter; //this is the character
     public float Gravity = 9.8f; //this is gravity 
     public float JumpForce = 10.0f; //this is the force of jumping
     public float DistanceFromGroundMargin = 0.2f; //the player can jump if within this distance from "ground"
     private RaycastHit Hit; //this is the raycast to check if the player is grounded and to find the normal of the polygon underneath the player
     private Vector3 MyNormal = Vector3.zero; //this is the normal of the polygon underneath the player
     private float DistanceFromGround; //this is the distance from the ground when grounded. it equals half the height of the collider minus the position of the collider relative to the orgin of the gameobject the collider is attached to incase the collider is off center from the gameobject
     public CapsuleCollider TheCollider; //this is the collider needed
     private bool IsGrounded; //the boolean to tell whether or not the character is grounded or not (touching ground)
     // Use this for initialization
     void Start () {
         TheCharacter.useGravity = false; //turns rigidbody global gravity off
         TheCharacter.freezeRotation = true; //stops unwanted roatation from rigidbody physics
         MyNormal = TheCharacter.transform.up; //sets the normal equal to the rotation of the players local up 
         DistanceFromGround = TheCollider.bounds.extents.y - TheCollider.center.y; //read the variable above
         Physics.Raycast (transform.position, -transform.up, out Hit); //casts a ray to for the next line to...
         IsGrounded = Hit.distance <= DistanceFromGround + DistanceFromGroundMargin; //check if the player is grounded by comparing the distance from where the ray was cast (gameobject center) to the object if any beneath it. if the distance is less than DistanceFromGround + DistanceFromGroundMargin then the player is grounded
     }
     
     // Update is called once per frame
     void FixedUpdate () {
         TheCharacter.AddForce (-Gravity * TheCharacter.mass * MyNormal); //adds a downward force in the direction of the characters local -up (downward) direction. this local direction shoudl be equal to the normal beneath the character at any given time
         Physics.Raycast (transform.position, -transform.up, out Hit);
         IsGrounded = Hit.distance <= DistanceFromGround + DistanceFromGroundMargin; //checks if the player is grounded... for more info read the check in the start function
         if (Input.GetKey (KeyCode.Space) & IsGrounded) { //if the space bar is pushed and the player is touching ground then...
             TheCharacter.velocity += JumpForce  * MyNormal; // change the characters velocity to an upwards force using the JumpForce variable
     //        TheCharacter.AddForce (JumpForce * TheCharacter.mass * MyNormal);
         }
     }

when I jump it doesn't jump the same amount everytime. any solutions? just smash the space bar after you set up the character.

(to set it up create a capsule and (optional camera that is child to the capsule) add a capsule collider and rigidbody and assign them to the script once the script is attatched to the capsule then pound space and watch in the scene view)

I tried addForce and velocity to see if the problem stopped and I even multiplied by jumpforce and character mass and the normal but still no change (I tried without character mass as well)

thanks for any help. :)