|
Page 1 of 2
Replica Watch Basics 102
An expansion of Ziggy's earlier introduction to watches article, this time he focuses on answering frequently asked questions.
Lets expand on our basics and move on to other terms and information.
Glossary:
Crown
- the part that you hold to wind, set the time etc.
Screw-down Crown
-
a crown that is water-resistant and screwed down to seal it. To
unscrew, turn the crown Counter Clockwise as viewed from the crown side
of the watch. To screw the crown back down, press gently towards the
case, and turn the crown Counter Clockwise (this is not a typo), when
you feel a click – instantly stop, maintain pressure toward the case,
then screw the crown down Clockwise. What this does is make sure the
threads of the crown and the case tube, are lined up before attempting
to screw it down. Doing this will reduce the chances of the threads
getting stripped.
Case tube
- the tube in the case of the watch that the crown sits in.
Crown positions
-
a crown will have either 2 or 3 positions. A watch with no calendar
function will have 2 positions, the inner one (closest to the watch
case) for winding, and the outer one, with the crown pulled out, for
setting the time. Never leave the watch in the time setting position,
if you do and the watch is running, the watch will attempt to turn the
keyless works and jam up. A watch with a day/date will have 3
positions, 1 winding, 2 for setting the day and date – you set the day
or date by turning CCW or CW, on some models you can only set the date
between certain times (see other posts to find the models). The 3rd
position is for setting the time.
Hacking Lever
- a
small lever connected to the clutch gear in the keyless works. When the
crown is pulled out to the outermost position, the lever moves across
and touches the outer edge of the balance wheel, and stops the movement
from running. Its use is to allow you to set the time to the exact
second.
Quick date changeover
- on some movements, the
date will change instantly at or around midnight. Models that have this
feature include many Asian movements, ETA 2801 series (2824-2, 2836-2),
the 2892A2 and it's variants. These work by having a type of spring
mechanism that is charged up and releases just as the watch turns over
at midnight. If the watch doesn't switch at exactly at midnight, it's
not a flaw with the watch. Even if the hands are installed exactly when
the date switches over, the exact moment that the date switches can
vary somewhat.
Why? because the date switchover is dependent on the
datewheel setting spring to hold it in place, as the switchover spring
builds up pressure, it's only being held back by the setting spring.
Once the tension is equal between the springs, the switchover spring
builds up just enough pressure to overcome the tension in the setting
one - and the date changes. These are springs and there are various
gears, the datewheel itself, and all of this can and will vary in
tension, spacing, spring pressure etc. If your expecting perfection in
a mechanical watch, your looking for more than it's designed to
do!really who cares if the date switches at 12:10 or 11:45!
Beat
-
beat is the term to describe the position of the balance wheel, the
pallet arm, and the impulse wheel. All three have to be lined up and in
perfect coordination for the watch to work correctly, it's just like
the timing on a car engine, the camshaft, the intermediate shaft and
the crankshaft, all have to be lined up or the pistons will hit the
valves! the same is true in the watch. Adjusting the beat is done by
moving the "at-rest" position of the balance wheel - via the hairspring
stud arm. It is verified on the watch timing machine. If the movement
is out of beat, the balance has a larger swing one way than the other
and will not keep accurate time.
Rate
- how fast or
slow the watch runs. This is adjusted by moving the regulator arm which
holds the regulator pins through which the hairspring passes. Moving
this arm changes the "effective" length of the hairspring (effective
meaning it does NOT affect the beat), shorter spring, faster swings,
longer spring, slower swings! Most watch movements have an adjustment
screw or arm to make minor adjustments to the rate, the rule of thumb,
1 increment is equal to approx 5 seconds per day.
|
Articles 
