Orient F6/F49 series movement accuracy regulation guide
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This guide is specifically tailored to the Orient F6 platform (including
F6xxx and F49xx) automatic movements but may work for other mechanical 
movements of Orient or other brands as well. Your mileage may vary. For 
several Orient F6/F49 movements in a good working condition, this method has 
proven to achieve the accuracy of ±1 second per day for the 24/7 continuous 
wearing mode, making it to the quartz-grade deviation of 30 seconds per 
month at most. This method is convenient for following at home, away from 
any specialized watch services.

Besides the watch itself, you will need:

1. A caseback opener tool suitable for your watch model.
2. A timegrapher (hardware or software) capable of measuring the movement's
accuracy in the "dial down" position. I have tested this method solely with 
the acoustic-coupled software timegrapher for Android called "Watch Accuracy 
Meter".
3. Knowledge of the current daily deviation value (let's call it DDBR - daily
deviation before regulation) based on the previous accuracy measurements 
every 24 hours for several days. If you have bought and set a new watch, I 
recommend wearing it at least for a week noting the deviation from the 
reference time every single day at about the same time, and only going for 
the regulation process when the run of the movement settles according to 
your daily routine and when you know exactly one value of its daily 
deviation. For example: if you bought an Orient Tristar and started wearing 
it 24/7 with the second hand deviating +5s from the reference time at the 
time of setting (as the F4902 are non-hacking), then you record deviation 
values throughout the week, e.g.: +11, +21, +30, +38, +45, +52, +59. At this 
point, in this example, you can be pretty sure your DDBR value is settled on 
+7 spd.
Note: a common mistake is to take the average value over the entire
measurement period as the DDBR. This might be suitable from the consumer's 
perspective as an overall accuracy estimation, but is completely useless for 
regulation purposes. To get DDBR, you must register the deviation every 24 
hours and fix the difference between the current and the previous one. Once 
the difference is stable, this is your DDBR.
4. A small (<=2mm) flathead screwdriver with a non-magnetic tip.

With these four things, we can start the regulation process:

1. Unscrew the caseback and lay the watch flat with the movement facing up.
If the rotor is covering the balance wheel, rotate the rotor so that it 
isn't.
2. Using your timegrapher (hardware or software), measure the current
deviation in this "dial down" position. Let's call it TGDBR (timegrapher 
deviation before regulation).
3. Calculate the target timegrapher deviation (TTGD) by subtracting the DDBR
value from what you've just measured: TTGD = TGDBR - DDBR.
4. Now, you are ready to perform the adjustment. Find the correct lever above
the balance wheel (and, unless you have a hardware timegrapher, don't ever 
touch the other one!) and the direction in which you need to move it. They 
usually are marked with "+" and "-" signs so you can't get confused, but 
anyway, check the docs for your movement if you have any. For Orient F6 
platform movements, the speed regulation lever is the thinner one, closer to 
you, and the directions are the following: slower clockwise, faster 
counterclockwise. So, if your TGDBR is greater than your TTGD, then you need 
to slow down the watch, and if your TGDBR is less than your TTGD, then you 
need to make it faster. This helps to determine the direction of your first 
movement.
5. Using the non-magnetic screwdriver tip, gently and slowly move the speed
regulation lever in the determined direction until you reach the desired 
TTGD value on the timegrapher. Move it just a tiny bit at a time, then wait 
for ~10 seconds and then measure. It is extremely easy to overshoot and 
requires micrometric precision, so you might have to go back and forth 
several dozen times before reaching the actual TTGD value.
Note: if your calculated TTGD value (or the measured TGDBR value) is a
fraction (like +7.5 spd) and your timegrapher doesn't support displaying 
such values, then the measurement must oscillate between the nearest integer 
values (in this case, +7 and +8). This is exactly why this method can only 
achieve the ±1 spd accuracy at all.
6. Once the TTGD is correctly set on the movement and the timegrapher doesn't
show any anomalies, screw the caseback on and enjoy your newly regulated 
mechanical watch.

Example with real regulation of my Orient RA-AA0001B (F6922): the DDBR value
was settled on +8.5 spd, the TGDBR value was measured as +13.5 spd, so the 
TTGD value is 13.5 - 8.5 = +5 spd.
Another example with real regulation of my Orient RA-AB0F09L (F4902): the
DDBR value was settled on +2 spd, the TGDBR value was measured as +10 spd, 
so the TTGD value is 10 - 2 = +8 spd.

Closing notes:

1. On the first day(s) immediately after regulation, the watch may run 0.5s
faster than expected, so please wait until the accuracy settles for another 
12 to 48 hours. Hacking movements tend to go faster after resetting the 
second hand, so you might have to wait even longer than that.
2. This method relies on the fact that the accuracy difference (not absolute
values, but difference) in the "dial down" position of the watch is exactly 
the same as the accuracy difference in the overall daily average position of 
the watch. This has been tested for Orient F6/F49 movements but might not be 
suitable for others.
3. If, some time after the regulation, your watch starts deviating
systematically again, then you may repeat the whole process, but this might 
also mean the movement might have some internal problems and the watch might 
be in a need of service (e.g. demagnetization or lubrication). Keep in mind 
that this method is only efficient for the movements that are healthy in all 
other aspects except accuracy.
4. If your movement is non-hacking (like F4902) and several seconds slow,
take off the watch, position it vertically with the dial towards you, and 
gently shake it with the movement's oscillating frequency, e.g. for F4902 it 
will be 3 full shakes per second. Stop every 2-3 seconds to check whether 
the second hand has moved to the desired position according to the reference 
time. Afterwards, you may also need adjust the minute hand position as well.

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