Abstract: Apparatus for fabricating flat floor trusses or other wood structures, the apparatus including a number of wood member support frames securable together in end-to-end abutting relation with each of the frames having a tongue at one end thereof and a groove at the other end thereof whereby the groove of one of the frames receives the tongue of another of the frames to facilitate rapid set-up of the frames with the frames in proper alignment with one another. Lumber stops are provided on support frames for accurately positioning the chord members of the truss and for preventing outward movement thereof, but yet permitting a completed truss to be readily lifted from the support frames without unclamping or releasing the stops and without undue friction from the stops. The support frames further include a plurality of wood member support platforms adjustably movable along the length of the support or readily removable therefrom so as to support the wood members at the joints of the truss being formed.