The calculator mechanism consists of just under 700 parts, arranged in three major assemblies:

• The base and covers, including the rotor supports, winding handle, and the carriage positioning mechanism at the front left (194 parts, more or less).
• The rotor, consisting of the ten pin-wheels, some interlocks, and part of the carry mechanism (223 parts).
• The sliding carriage, with the counter and accumulator registers and the back-transfer mechanism (267 parts).

The mechanism is built on a heavy die-cast base about 190mm (7-1/2") wide by 140mm (5-1/2") deep, formed into a pedestal about 25mm (1") high. The two die-cast end plates are dowelled and screwed to the base, and are supported laterally by a heavy steel plate across the back. The extended bushings for the winding handle and the rotor lock shaft are screwed to the right-hand end plate.

The carriage slides on the six bearing surfaces in the channel at the front of the base. The 10mm hole in the centre of this channel is for a stop plug which limits the carriage travel. The smaller hole to the right is threaded, possibly for a locking screw to secure the carriage during shipment, or to attach the machine to a bench.

The sliding carriage is built on a one-piece die-cast frame about 210mm (8") wide. The counter and accumulator registers are supported between the three vertical pillars. The slots and holes locate the various levers, shafts, and detent mechanisms. The carriage is positioned by a toothed rack which attaches to the lower front face.