Abstract: A motion device including a carriage for traveling along a rail. The carriage can have at least one rotatable fixed position roller, and at least one rotatable adjustable roller that is movable relative to the at least one fixed position roller for self compensating for play between the rollers and mating surfaces of the rail. Each adjustable roller can be part of a movable roller portion movably mounted to the carriage. The movable roller portion can be adjustably movable by a self adjustment mechanism. The self adjustment mechanism can include a mechanical advantage pushing member for movably engaging the movable roller portion. The mechanical advantage pushing member can be resiliently biased against the movable roller portion by a biasing arrangement. The biasing arrangement can cause movement of the mechanical advantage pushing member and the movable roller portion for moving the at least one adjustable roller for self compensating for play.

Abstract: A motion device can include a carriage for traveling along a rail. The carriage can have at least one rotatable fixed position roller, and at least one rotatable adjustable roller that is movable relative to the at least one fixed position roller for self compensating for play between the rollers and mating surfaces of the rail. Each at least one adjustable roller can be part of a movable roller portion movably mounted to the carriage. The movable roller portion can be adjustably movable by a self adjustment mechanism. The self adjustment mechanism can include a mechanical advantage pushing member capable of movably engaging the movable roller portion. The mechanical advantage pushing member can be resiliently biased against the movable roller portion by a biasing arrangement. The biasing arrangement can be capable of causing movement of the mechanical advantage pushing member and the movable roller portion for moving the at least one adjustable roller for self compensating for said play.