watchmaker service of an omega seamaster de ville cal 1020

Reference number: 000-010

Chris Nicholas 10 September 2017 of 39

Worksheet/Receipt

Owners name: Self

Address: n/a

Telephone: n/a

Description of item(s) received, including accessories:

Omega Seamaster De Ville Cal 1020 Ser 39070474

Work required based on initial inspection:

Watch runs fine but has not been serviced for many years.

Full service on movement with new Omega 10101208 Mainspring.

Clean case.



As received:



The movement comes out of the front of the case so, bezel and crystal are removed. There is a scratch on the

dial at 12:00 but not particularly noticeable.

Hands removed.



Movement extracted from case.

Dial removed.



Rear of movement with auto mechanism removed.



Watch runs with lowish amplitude.



Movement is dry and dirty.



Disassembly and cleaning

Movement fully disassembled, jewels pegged and all parts cleaned in Elmasolvex RM 4 jar automatic cleaning

machine:

Jar 1: Cleaning Elma WF Pro 5 minutes clean + 2 minutes spin off

Jar 2: Rinse 1 Elma Suprol Pro 3 minutes rinse + 2 minutes spin off



Drying chamber 7 minutes drying



Parts after cleaning



Cleanliness and condition review

Jewels, bearings and posts checked in plates and bridges:



Wheels, arbor and other components reviewed – some samples:

Barrel arbor is fine although slightly marked

All wheels are fine – some shown.



Review of the keyless works and other dial side items. - all fine.



Review of the automatic mechanism and bridges. Some samples, all fine.



Parts required after review

Parts list:

Omega 1020.pdf

Omega 10101208 Mainspring



Oiling

Lubricants used:

Moebius 9504 grease Keyless works

Moebius HP1300 oil Typically on all bearing surfaces unless otherwise specified.

Moebius 9010 oil Balance Shock protection end jewels, escape wheel and fourth wheel pivots.

Moebius 9415 grease Pallet jewels.

Moebius 8941 Fixodrop Epilame used for escape wheel and pallet jewels.

Kluber P125 Braking grease for barrel wall.



Assembly

Polishing shock protection jewels on watchmaker’s tissue with a buff stick (stock photo).

Oiled and installed. Balance and cock mounted on the bare plate. Checked concentricity and flatness of

hairspring.



Spring adjusted to be central in regulator pins.



Centre seconds pinion and spring installed:

End shake in barrel reduced.



New mainspring and fitted in barrel.

Train, train bridge, barrel and bridge fitted:



Winding mechanism fitted.

Keyless works fitted, fork and balance and base movement running:



After 20 minutes, the escapement is oiled with a small drop of 9415 and the escapement is cycled a few times

before adding another drop. This continues until all the escape wheel teeth are oiled.

This runs for a few days and I make any adjustments.



The cannon pinion on these calibres is fitted to the minute wheel off the movement using the staking set.



Third wheel cannon pinion and all calendar mechanism fitted to dial side of plate.

Date indicator guard fitted



Day indicator mechanism fitted:

Dial and hands re-fitted.



Auto bridge pieces assembled.

As this has a movement ring, it can be fitted upside down in the movement holder when that’s been added

without risking dial damage. Auto bridge fitted.



Rotor added and movement build is complete.



Case and bezel are cleaned.



Complete and fitted in the case:



Timing and testing

For calibres of this age that are not chronometer specified, Omega typically call for testing over 3 positions:

CH (dial up); 9H and 6H and specify a maximum rate variation at full wind of 25 seconds/day over the three. In

the pictures below, you can see that this movement has a variation from -2.1 to +5.6 seconds/day so that’s

well within specification at 7.7 seconds/day. Beat error should be under 0.8ms and here it’s 0.3ms maximum

so, again within spec.



As usual I’ve added the other 3 positions as they can be useful in seeing faults or improvements. The six

testing positions only have a variation of 13.1 seconds/day, still within the 3 positions specification. This is a

very good result for one of these and close to chronometer spec.



Omega usually call for these calibres to be tested again after resting for 24 hours from full wind and typically

require a maximum of 35 seconds/day variation over those same 3 positions and a minimum amplitude of

160° to 200° dependant on calibre. This movement has a variation of 10 seconds and a minimum amplitude of

228°over 6 positions so is well within specification. There’s one other requirement and that’s a minimum

power reserve of 48 hours from full wind – this movement has more than 49 hours so is fine.

Note: This calibre has a lift angle of 52°.

Just some notes on how to read these graphs:

Positions CH FH (CB) 6H 9H 3H 12H

• The lines should be smooth without undulations.

• Along the top are:

o The rate in seconds per day.

o The beat error – basically the time difference between tick-tock and tock-tick.

o The amplitude of the balance – ideally 250-320° horizontal and 240-280° in others at full wind but dependant on

movement age/condition - higher is usually better. Many specs only call for a minimum amplitude after 24 hours.

• Along the bottom are:

o Mode of the tester at both left and right.

o The beat number: calibre dependant – 19800 A/h is equal to a 2.75 Hz.

o Lift angle: calibre dependent and is used for amplitude calculation. If specified incorrectly high, it overestimates the

balance amplitude by about 6° for a 1° increase in lift angle.

Longer term running test

To see how the movement runs over a test period of some days in various positions. This is supposed to

simulate typical usage and how the watch will run in the real world. I’m using this for this calibre:

• Full wind and set time.

• Day 1: 24 hours rested in 9H position

• Day 2: 24 hours on auto winder

• Day 3: 24 hours rested in dial up position

• Day 4: 24 hours on auto winder

• Day 5: 24 hours rested in 6H position

• Day 6: Allowed to run down in 3H position to check power reserve from auto wind.

• Day 7: Full wind, test to obtain final 0H figures.

• Day 8: Rested in dial down position and test again to obtain 24H figures.

• Day 9: Rested in 12 H position to re-check power reserve.

This doesn’t identify any issues and everything works normally and within specifications and the watch winds

fine by hand and on the auto winder. Average rate over the first five days of the test is +4 second/day.



Water resistance test to 30m

The test is made by pressurising the tester to 3.75 bar (approx. 37.5m water depth) which is 3 bar (30m) plus

a 25% safety factor. After an hour with the watch sitting in the air part of the chamber at that pressure, the

watch is submerged and the pressure released over 10 seconds. If the watch has leaked during its one-hour

soak, then the internal pressure will be higher than the external and air bubbles will be seen as the higher-

pressure air escapes from the case.

This watch doesn’t have a specified water resistance because of its design so I defaulted to the basic 30m

test but, checked it empty first. This watch fails that test and can only be classed as dust resistant and was not

tested after the case was finally closed.



Overall

The movement has been serviced with parts replaced as necessary (just a mainspring here) and performs well,

keeping time well within the requirements for this calibre. Its fastest rate is in 3H position and its slowest

position is 9H. By resting in either of these positions overnight, the timekeeping can be slightly tweaked as

required. In my long-term tests which are meant to simulate typical usage, it is averaging +4 seconds per day.

The watch will not pass a 30m water resistance test so, caution is advised. It’s a dress watch and this shouldn’t

present any problems.

The 1020 calibre isn’t the most collectable but it is far better that the 1000 series and Omega make this clear

in their service document. From the 550 series, there are a few advantages with the date setting and the

hacking feature plus, these are a high beat calibre (28800 A/h) and even with the day feature they are a little

slimmer. Typically, they are good timekeepers and this one is no exception being close to chronometer

specification.

The movement has a quick set day and date and the crown functions in the following manner.

Manual winding of the watch – position 1. Winding can be for an infinite number of crown turns as it’s

an automatic but 20 turns from zero charge is more than sufficient.

Date setting mode – position 2 by pulling the crown out one position. The crown can be turned in

either direction and will change the date. Best to do this with both hands in the lower area of the dial.

Hand and day setting mode – position 3 by pulling the crown further out. The watch will stop due to

the hacking feature. Rotating the crown clockwise changes the day (the hands also rotate backwards) and

turning counter clockwise will only move the hands for time setting. Again, best to set the day with both

hands in the lower area of the dial.

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watchmaker service of an omega seamaster de ville cal 1020

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