A motion control apparatus (10) in the form of a linear brake includes a camshaft (23) rotatable in a housing (11) moveable along a linear rail (30). The camshaft (23) is rotated by a gear motor (15) causing an eccentric engagement portion of a cam follower (24) to abut with a facing (12) which engages the linear rail (30) to provide a clamping force thereon. A damper (25) is received on a dowel pin (14) secured to the housing (11) and received in a U-shaped groove in the camshaft (23) to inhibit further rotation of the camshaft (23). A shim (20) separates the outer races of the bearings (22) receiving the camshaft (23) to preload the first and second bearings (22).