Description
The 9 x 1 ligne pin lever movement in pillar construction was probably the first wristwatch movement from Timex. It was replaced by the caliber M22, which only differs by the position of the V-Conic bearing screw, which is on the dial side on the M21 and on the movement side on the M22.
This movement is of very simple quality, you won’t find any bearing or other jewels there.
The execution is very cheap, in theory, you can make a service on it, but in reality, you don’t want to, and you probably wouldn’t succeed either.
An additional oddity is, that the mechanics of the simple rocking bar winding system is located on the inner side of the base plate. The fact, that it is permanently set under tension makes any work on it difficult.
As most Timex movements, the M21 is difficult to work with, one of the reasons is, that the hairspring is fixed on the gear train plate.
Because of this, it is advised to re-mount a taken apart movement on the inside of the gear train plate.
The construction is classical, with mainspring barrel, directly driven center minute wheel, third wheel, seconds wheel and escape wheel.
Optionally, the third wheel could indirectly drive the center seconds pinion, where available.
As balance, a simple two leg anular balance is used, with rugged axles, beared in the typical V-Conic bearings by Timex. Because of this, no further shock protection is required.
It beats slowly with 18000 A/h and can be regulated with a simple, short, stamped regulator arm.
On the dial side, a simple, riveted rocking bar winding system is used.
It’s nice to see the height adjustment screw of the balance bearing, located on the dial side of the Timex M21.
The ratchet is located, like on most rocking bar movements, on the dial side. The ratchet wheel is only plugged into the barrel axle. To make it stay in this position, a copper latch is used.
Technical data
Manufacturer: | Timex |
Caliber: | M21 |
Size: | 9 x 10''' (measured: 19,7 x 23,6mm) |
A/h: | 18000 |
Escapement: | Pin lever |
Balance types: |
monometallic anular balance (two legs) |
Balance bearing / direction hairspring: | Counterclockwise |
Moveable stud: | no |
Adjust mechanism: | Short regulator arm |
Construction: |
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Construction type: | pillar construction |
Winding mechanism: | rocking bar winding system |
Features: |
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Inventory number: | 23003 |