A foldable frame assembly includes first and second frames pivotally connected to each other and respectively having a wheel-carrying end and a foot end. The tabletop bracing member is pivotally connected to the first frame in proximity of a handgrip portion, and supports a machine thereon such that in a propped up position, the center of gravity of the machine is disposed rearwards from the table top bracing member. The tabletop bracing member has a retaining region brought to engage a retained region on the second frame. The base prop is disposed to sit on the ground surface in the propped up position so as to relieve the frame subassembly of the mass of the machine, thereby facilitating displacement of the frame assembly to a folded or unfolded position. A locking member is disposed to place engagement of the retaining region with a selected one of the first and second retained regions.