The invention relates generally to conveying systems, for moving work pieces from work station to work station including conveyors which generally move at a constant speed and include load carrying units which can be coupled for movement therewith between work stations and uncoupled from the conveyor so that they will be stationary at the work stations while work is done on a work piece carried by the load carrying units. More particularly, the present invention pertains to improved systems, methods, and apparatuses for providing locomotion and control to a conveyor system including surface-mounted drive system and adjustable, automatic take-up system with floating drive chassis. The present invention also pertains to elevated conveyor systems comprising many of the same components as the surface-mounted conveyor systems.