Movement Care
An automatic movement - the type used across all Seiko mod builds - is powered by a weighted rotor that winds the mainspring in response to the wearer's wrist motion throughout the day. Calibers such as the NH35 and NH36 typically offer approximately 41 hours of power reserve, allowing the watch to continue running for roughly a day and a half after being removed from the wrist. Should the watch stop following a period of non-use, it can be restarted by gently turning the crown approximately 20 to 30 times until the second hand begins moving, after which normal wear will maintain power.
Two factors warrant particular attention during use: magnetism and impact. Magnetic field strength diminishes rapidly with distance, so carrying a phone or working near a laptop poses little practical risk to timekeeping. The concern arises specifically from prolonged, direct contact with a strong magnetic source, such as resting the watch on a laptop speaker for an extended period or leaving it overnight on a wireless charging pad - which can magnetize internal movement components and cause the watch to run fast. Even when this occurs, the effect is fully reversible: professional demagnetization resolves the issue within moments and causes no lasting damage to the movement. Impact is a separate consideration. Significant force from sports or accidental collision can disturb the balance wheel and affect accuracy, making it advisable to remove a mechanical watch during high-impact activity.
Movement should be serviced periodically
As with any mechanical movement, periodic servicing plays a central role in preserving long-term accuracy. Industry practice generally recommends professional servicing every 3 to 5 years, sooner if the watch is worn daily under demanding conditions. Owing to their widely standardized architecture, NH-family movements can be serviced by watchmakers across many regions at a fraction of the cost associated with proprietary Swiss calibers - a practical advantage that makes Seiko-based builds, including those from Craft Mod, straightforward to own and maintain over time.