Abstract: A zoom lens includes a lens group mounted in a cam barrel mechanism which includes a fixed barrel with a cam barrel rotationally mounted thereon. The lens group has a pin which projects through an axially extending clearance slot in the fixed barrel and a compliant feature on the pin removes the clearance between the pin and the slanted cam slot in the cam barrel so that as the cam barrel is rotated the lens group translates axially within the fixed barrel. The fixed barrel has an endcap with array of centering orifices mounted thereon and a beveled surface which is engaged by an outboard edge of the cam barrel. The cam barrel is urged against the endcap by a wave washer disposed between the cam barrel and a base. Radially disposed with respect to the cam barrel are a pair of spaced lugs and a bowed sheet spring which engages the cam barrel to urge the cam barrel against the lugs. The wave washer and bowed sheet spring positively locate the cam barrel with zero clearance.

Abstract: A rolling ball element mount and barrel interface comprises a barrel and an element mount sharing a common lateral (X, Y, Z) and angular (.THETA..sub.X, .THETA..sub.Y, .THETA..sub.Z) frame of reference located at a center of said barrel, the element mount adapted to fit inside the barrel axially along Z. A first component, including at least two rolling balls, is disposed between and adapted for contact with the element mount and the barrel for (i) constraining the element mount in lateral positions X and Y and angular positions .THETA..sub.X and .THETA..sub.Y and (ii) moveably coupling the element mount and the barrel in the axial direction. A second component, including at least one rolling ball, is disposed between and adapted for contact with the element mount and the barrel for (iii) constraining the element mount in angular position .THETA..sub.Z in cooperation with the first component and (iv) moveably coupling the element mount and the barrel in the axial direction.