Six degree of freedom hand controller

A 6 degree of freedom hand controller, comprising:

• a handgrip member being substantially spherical in shape and including a point disposed substantially centrally of said member;
• an elongated shaft member for supporting said handgrip member such that said handgrip member is rotatable, from an initial position, about said point, said rotational motion of said handgrip member about said point being resolvable into motion about a pitch axis, passing through said point, a roll axis at right angles to said pitch axis and also passing through said point, and a yaw axis, at right angles to both said pitch axis and said roll axis and also passing through said point;
• said elongated shaft member being movably supported such that said handgrip member is movable, from said initial position, in translational motion resolvable into motion along said pitch, roll and yaw axes and through said point;
• whereby, said rotational motion of sid member comprises motion of sid member about said point;
• and
• whereby the effective lines of thrust of said translational motion of said member pass through said point;
• whereby translational motion is detected by movement of a shaft along a respective translational axis, said means for sensing translational motion comprising a pair of load cells, each one of said pair being disposed on a different side of said shaft in the direction of motion thereof, a spring between each said load cell and its respective shaft, and a button disposed at the free ends of each of said springs;
• the space between said shaft and said button comprising the free play of the handgrip member along the respective translational axis;
• whereby, when said handgrip member is moved so that said shaft touches said button, this comprises a soft stop;
• and
• when said shaft is moved so that the spring is no longer compressible in that direction, this constitutes a hard stop.