Inside a
Quartz Watch
Page 1 of 2
Created 02-26-2002
The Victim
This watch developed an intermittant and was no longer reliable so I thought that I would take it apart to see just what is inside a quartz watch.
The watch is a Seiko SQ100 quartz alarm chronograph. The movement, a Seiko 7T32 is used in MANY seiko models.
Opening it up
I removed the screw back and got ready to remove the movement. Two detents "P" had to be pushed in to remove the crowns "C". NOTE: this is done with the crowns in the IN position.
Once the crowns were out the movement can be gently pried out of the case (the pushbuttons stay in the case).
Removing the Hands
I used a hand removal tool to remove the hands so that the face could be removed to begin disassembly of the date mechanism. The Date Mechanism
Once the face was removed the adapter ring "R" could be separated from the movement. NOTE: The adapter ring "R" is the only thing that varies in Seiko watches using the 7T32 movement. Changing the size of this ring and the face allows this movement to be used in many watch cases.
Date Wheel Thrust Plate
The date wheel is held on to the front plate by a stainless steel thrust plate. This plate also serves to hold one end of several gears. The thrust plate is removed from the front plate by turning 2 white nylon cams "S" 90 deg.
Date Drive Gear
With the thrust plate removed the date wheel drive gear "C" and the hour hand drive gear "H" can be seen. The hour gear "H" has 9 teeth and the date gear "C" has 18 teeth resulting in a 2:1 ratio (for each 2 revolutions of the hour gear, the date gear rotates once).
Date Wheel Removed
This picture shows the date wheel removed exposing the front plate.
