< Knuckle Coupler >
Castings for the knuckle coupler (O.S products): The left one is heavy-duty gunmetal casting which I use as the rear coupler. The right one is nice-looking (functional) brass casting which I use as the front coupler.
The coupler pockets are cut from a bright mild steel bar. Note the advance holes to reduce the cutting labor of milling operation.
Coil springs for buffering are coiled from a stainless steel wire in the lathe.
Both end of the coil springs are squared in the sharping tool.
Knuckle coupler casting is cut and drilled for the spring housing. In advance the coupler pin of round stainless steel is silver soldered to the casting and filed to the shape.
Completed knuckle coupler.