Seagull ST1903 User Manual

ST1903 Mechanical movement
User Manual Instructions
Thanks for using seagull ST1902/ST1903 movement. Please read the following
instructions carefully before use：
FUNCTIONS：
Regulator of Center hour hand, minute hand, second hand. 3-point minute
counting instructions, 30 points / circle; 6 o'clock hour hand instructions (synchronized
with the center hour hand); 9 o'clock small seconds hand, hand winding. (1903
movement 6 o'clock h
our hand, 24 hours / circle, others are same with the 1902
movement).
SPECIFICATION：
Calibre diameter：Φ31.3mm; Thickness：H6.25mm; 21600vibrations per hour；
22 Jewels
ADJUSTMENTS:
Crown position “1” ，manual winding.
Crown position “2” ，corrector.
Press “M” button，timing begins;
Press “M” button again，timing stops;
Press “N” button，return to zero.
ASSEMBLY:
1. Assemble dials and hand:
2. Press M timing ON/OFF button to stop counting seconds; then press
N button, Counting
back to zero.
3. Put the movement on the special base and remove the craft hand. (Use a special tool to
pull up the craft hand vertically to avoid bent or broken)
4. Unscrew the two fixing screws on the movement and tighten the fixing screws after
installing the dial.
5. Gently pull the crown to the 2nd gear position, install 6 o'clock 12o'clock small seconds,
aim at 6 o'clock "12" characters.
6. Install the 3 o'c
lock chrono hand and align the 3 o'clock "30" character.
7. Install the center hour, the minute hand; Do not deviate when the hour/minute hand
points to"12" characters.
8. Install Counting seconds (Center long second hand). Install hands when align the 12
o'clock character. Error <0.1 seconds
9. Install Small seconds of 9 o’clock.
INSPECTION：
1. Each hands should be parallel to the dial with average gap. Do not deviate the hour hand
and minute h
and of 12 o’clock.
2. Seconds timing function:(1)press M button, timing begins;(2)press M button again, timing
stops;(3)press N button, return to zero.（Center seconds counter zero, pointing to "12"
characters, 3 o'clock minute hand aimed at "30" characters.) Confirm that the countdown /
zero return function are reliable.
LOAD IN THE CASE
Clean dials and cases, load the movement into the case without any dirt. Put two clamps into slot, lo
cking
screws and screwing the back case. (Put the holder into the case straight if no clamps)
ATTENTION: Do not press the position “4” N button to return zero when the
Chronograph second hand moves. You should press position “2” M
button to stop timing then press position “4” to return zero. Timing range 0-30 minutes. The hour
hand of 6 o’clock should be same as the center hour hand without timing function.

Seagull ST1903 Specifications

General

Jewels	21
Functions	Hours, minutes, small seconds, chronograph
Case Material	Stainless steel
Strap Width	20mm
Movement Type	Mechanical
Movement	ST1903
Frequency	21, 600 bph
Dial	Various colors
Crystal	Sapphire or Mineral
Strap	Leather or Stainless Steel
Clasp	Deployment or Tang Buckle

Summary

Functions of ST1903 Movement

Hand Functions and Timing

Describes center hour, minute, second hands, 3-point minute counting, and 6 o'clock hour hand functions.

ST1903 Movement Specifications

Calibre and Jewel Count

Details the movement's calibre diameter, thickness, vibration frequency, and jewel count.

ST1903 Movement Adjustments

Crown and Button Operations

Explains crown positions for winding and correction, and button functions for timing control.

ST1903 Movement Assembly Guide

Hand and Dial Installation Steps

Provides sequential steps for assembling dials, hands, and securing the movement.

ST1903 Movement Inspection

Hand Alignment and Timing Checks

Details checks for hand parallelism, gap, and validation of timing and zero return functions.

Loading Movement into Case

Case Loading and Securing

Instructions for cleaning and loading the movement into the watch case, securing it properly.

Important Attention Notes

Chronograph Second Hand Operation

Warning regarding pressing the 'N' button during chronograph second hand movement and correct reset procedure.