Complication Servicing

Servicing a complicated watch carries risks beyond those of a time-only movement precisely because a complication adds mechanisms — jumper springs, cams, racks, column wheels, hammers — that are frequently under tension even when the complication is not actively engaged, and that must be synchronised correctly with the going train and, in many designs, with each other. A watchmaker servicing a complication has to understand not only how to clean, lubricate and reassemble the added parts but how to correctly re-time their engagement with the going train, since a complication reassembled with even a slightly incorrect timing relationship can jam, fail to function, or in some designs damage itself or the going train when operated.

Calendar mechanisms require particular care around the midnight date-change jumper and, on perpetual calendars, the multi-year month-length cam: servicing generally avoids operating the date-change function while the mechanism is disturbed or partially reassembled, since forcing a date change out of its correct window of engagement is a well-known cause of jumper or finger-lever damage even in an otherwise correctly reassembled movement — professional practice around perpetual calendars specifically avoids adjusting the date manually during the several hours around midnight for exactly this reason, on assembled and disassembled examples alike.

Chronograph servicing requires disassembling and correctly re-timing the column wheel or cam-switching system so that start, stop and reset actions engage and disengage cleanly without dragging on the going train, and reassembly is checked functionally — repeatedly operating the pushers and observing clean engagement — before the watch is considered complete, since a chronograph that appears to reassemble correctly but engages with even slight drag can measurably affect the going train's own rate whenever the chronograph is running.

Repeaters and striking complications are considered among the most demanding complications to service competently, because their hammers, springs and racks operate under considerable tension relative to their small size, and because incorrect reassembly can cause a hammer to strike out of sequence, fail to fully reset, or in some cases release its spring's tension uncontrolled; this mechanical risk, alongside the rarity and value of most surviving repeating watches and clocks, is why repeater servicing is reserved in practice for specialists with specific, often apprenticeship-level experience on that complication type.

The overarching principle in complication servicing, consistent with this academy's guidance throughout, is that added mechanical complexity multiplies both the technical knowledge and the specific hands-on experience required to service a piece safely, which is why complications are routinely referred to specialists even by watchmakers otherwise fully competent with time-only movements, and why this lesson closes the academy's curriculum by reinforcing, rather than relaxing, the standing recommendation that valuable and complicated pieces belong with appropriately specialised professional care.