The following photos try
to show areas of the balance and hairspring that can have a large impact
on timing. This is more advanced and may not be something you want to
work with, but a good understanding of how this works will help you
understand issues you may have with your watch.
The following photo shows you the
position of the regulator pins and hairspring stud. Click on the photo
to enlarge it.
Most of the time you will want to see the stud
positioned about level with the balance cock and the hairspring positioned
between the regulator pins 2 to 3 mm from the bottom of the pins.
If your watch is not keeping time and regulating it
does not appear to help changing these positions may help.
After loosening the stud nut raising or lowering the
stud will do the same to the position of the hairspring in the regulator
pins. Raising the stud is especially helpful if the hairspring has a
tendency to come out of the regulator pins. Lowering it is helpful if the
hairspring itself is touching the balance cock. Either of these situations
make it impossible to accurately regulate the movement.
The next photo should help you visualize this. Again
enlarge the photo so you can see the details.
Another thing that impacts the timing is
the position that the roller jewel fits into the pallet and the position
of the banking pins. I can't photograph the former but can the latter and
that is the next photo. Every brand and grade of movement has different
positions for the balance cock and pallet and the relative position of
these two can make a big difference in the function of the balance. This
is work that is strictly in the purview of the watch maker. But I do
believe that shipping especially that involving long distances and
vibration can change these settings. I believe this
is especially true for recently serviced and lubricated movements where
there is no crud holding things tight. Ideally
the roller jewel will intersect the pallet dead center when the pallet is
centered between the banking pins. This is easier to say than to do. If
the banking pins are too close together the pallet jewels can't advance
the escape wheel, if they are two far apart the balance will over-bank and
the pallet jewels will lodge into the the escape wheel or may cause the
balance to have a bad amplitude and or beat error. Click on photo to
When any part of this is out of proper
alignment it can cause timing problems. Sometimes the balance may look
like it is oscillating very slow but the watch is gaining time. Sounds
impossible but it is actually very reasonable and here is why. When everything
is correct the balance wheel is swinging well
past where the banking pins stop the pallet, this consumes a few milliseconds
when the hairspring is allowing the balance to swing but the banking pins
are stopping the pallet so the escape is not being advanced. When the
balance appears to be slow running the balance makes a full swing and
advances the escape faster because the dead time is not be consumed.
I always make sure all of this is aligned
and a watch is keeping time before shipping but when there are problems I
usually find something that should not has changed position.