The frames are of very simple design. They are laser-cut from 12mm plate, being simply two plates 1015x150mm with slots 76mmx114mm for the take-up bearings to fit into. The height of these slots was obtained by measurement from the tram engine: however, my supplier sold me RHP take-up bearings, which have a slightly different profile to the Asahi ones on the tram. Thus, the 1.5" (37mm) springs used on it are about 6mm short for these slots. I fiddled this (by inserting a spacer under the springs), but if I started again I would make the slot 120mm high and use a 2" (50mm) long spring. These need to be fairly strong because as well as the weight of the locomotive, they need to be capable of taking the driver's weight too.
The laser cuts for these required no cleaning up at all, I simply bolted the two of them together and then drilled all the various holes in them. Next, I cut the (40x40x3) angle to attach the buffer beams (and, at the rear, to act as a seat support), and drilled those to attach them to the frames. Below is a photograph of the two frames and the front buffer beam, with holes drilled, and some of the angle used to attach them to the buffer beams temporarily bolted on.
The photograph below (taken 10/02/2002) shows the frames assembled, with the engine mounting plate temporarily put in place. The front coupling (supplied by Roanoke) has also been attached. At the rear of the photograph (leaning against the green coach) are the laser cuts for the cab front and back.