The epicyclic winding drum is mounted on a 5.5" axle (14a). Begin by constructing the winding drum. The boss of a 19-tooth pinion is passed through the centre hole of a faceplate without boss (the hole having been previously drilled out to 3/8"). The pinion’s boss is held in a short socket coupling (171a) that holds a 57-tooth gear (27a) in its other end. A worm drives this gear when the automatic electric rewind is activated.

Mounted on the faceplate adjacent to the 19-tooth pinion are two further 19-tooth pinions held in 19.2mm pivot bolts. The toothed end of each pinion is towards the faceplate. The face plate, a narrow double angle strip (846a), and a washer are held between lock-nuts on each pivot bolt.

The remainder of the winding drum cage can now be constructed. The other end of each narrow double angle strip is attached to a 2.5" gear wheel with a standard nut and bolt but spaced from it by two M4 washers. The remaining 6 holes around the perimeter of the winding drum are connected by a threaded boss, 4 black plastic washer spacers, and 2 M4 washers held together by a standard bolt at the threaded boss end and a 1.25" bolt at the other end.

A non-standard 2.25" axle passes through the double angle strip, face plate and 2.5" gear wheel. This axle carries a 19-tooth pinion (which meshes with the pinion on the pivot bolt), a collar, 4 M4 washers and a further 19-tooth pinion. This assembly is repeated on the opposite side of the drum.

A 57-tooth gear is bolted to a 2.5" gear wheel using four 14.7mm pivot bolts. The bosses of both gear wheels face in the same direction. Each pivot bolt holds a black plastic washer spacer and 2 M4 washers. Note that there are NO WASHERS under the heads of these four pivot bolts.

The boss of the 2.5" gear wheel is held in a short socket coupling, with a 15-tooth pinion held in the other end. A black plastic washer spacer separates the 57-tooth gear wheel from the winding drum. [This part of the drawing is exploded apart for clarity].

Two black plastic washer spacers and one M4 washer separate the entire assembly from the clock frame. The winding drum assembly is held together by the collar adjacent to the 57-tooth gear at the rear of a clock, and a second collar in at the other end of the 5.5" axle. All other parts (apart from these two collars) are not fixed to axle 14a. The positions of the front and back journals for axle 14a are indicated symbolically on the diagram by 3-hole strips.