A modular support system has individual frame modules each of which is formed by a series of standardized components that are secured together to form a generally elongate support structure for various uses, in particular a support structure for a conveyor. A truss frame module and a channel frame module are disclosed wherein both of the frame modules include a pair of elongate side frame members that are laterally spaced-apart and generally parallel, these frame members being secured together by a series of laterally-extending and transverse frame members. Specialized connectors attach to the ends of the laterally-extending and transverse frame members, which in turn are secured to the frame members. The components of each of the frame modules are substantially identical to the other so that they can be inverted or reversed without affecting assembly of the frame. The side frame members are made by profile cutting and roll forming an elongate metal plate.