Watch Service: Omega Speedmaster Professional. Cal 1861. (The Moon Watch)

omega moon watch

The Omega Speedmaster professional, aka the moonwatch. Its a classic watch with a rich history, and one of the most iconic watches in the world. It is powered by the Omega 1861 calibre and I’m sure many would agree its one of the most important watches Omega have ever sold.

There is a lot to say about this watch, far outside the scope of this blog post, but if you are interested to learn more about it then google is definitely your friend.

For anyone that doesn’t know, and if its not already obvious, the reason its called the moon watch is because it was the first watch worn on the moon. Although the original watch was actually powered by the Omega 321 calibre, these are extremely collectable now and pretty rare. However Omega are actually re-releasing some watches with this 321 calibre inside, although I’m sure they will lack the charm and character that the original models had.

This particular watch has come to me as its stopped working, a quick wind of the watch and the fault is clear – a broken mainspring. A broken mainspring can cause other issues, namely with the barrel it sits in, as the sudden dumping of power from the mainspring breaking can damage the barrel and the adjacent wheels. I will take extra care checking these parts for any damage.

So first up I remove the movement from the case. With white hands set against a black dial, the watch is about as legible as a chronograph can get.

omega 1861 calibre

First shot under the dial. The keyless works, motion works and part of the chronograph hour recorder components are visible.

omega 1861 calibre

It really is a lovely looking movement. The 1861 is the newer version of the 861 calibre, the difference being that it is rhodium plated where as the 861 is not. Its what gives the movement its silver colour, the bridges are actually made of brass.

omega 1861 calibre

I start off by removing the chronograph bridge, revealing the chronograph wheels.

omega 1861 calibre

Chronograph wheels removed.

omega 1861 calibre

Another shot with the chrono wheels removed.

omega 1861 calibre

I continue with the strip down, checking each part individually for signs of wear or damage as its removed.

All the chronograph parts are nearly removed, next I can remove the 3/4 plate to reveal the train and barrel of the watch.

omega 1861 calibre

Bridge removed revealing the train wheels and barrel.

omega 1861 calibre

This side is nearly complete.

omega 1861 calibre

Ill now make a start on the dial side.

omega 1861 calibre

Nearly complete and ready for the cleaning machine.

omega 1861 calibre

As suspected, the broken mainspring, this will be replaced.

omega 1861 calibre

So the movement has been through the cleaning machine, its been thoroughly cleaned removing any old oil and other debris that shouldn’t be in the movement. Its completely clean and I can begin to rebuild it and oil it to Omegas specification. I start on the dial side with the keyless works.

omega 1861 calibre

New Omega mainspring ready to be fitted.

omega 1861 calibre

Pallets, train and barrel all fitted back into place.

omega 1861 calibre

Once the 3/4 plate is re fitted, the watch can be wound up, oiled and tested on the timing machine. I do this at this point as if there is any problems with the actual running of the watch, It is better I find out now rather than later when the chronograph parts have all been added. If a problem shows up now I can likely quickly sort it, without having to strip the whole watch back down.

omega 1861 calibre

All looked good so I continue on the service.

omega 1861 calibre

This side is complete. Im not sure there’s many nicer looking chronograph movements.

omega 1861 calibre

Dial side now complete.

omega 1861 calibre

A shot of the watch before a new case back seal is fitted and its closed back up.

omega 1861 calibre

The finished article.

omega 1861 calibre

So the watch will go through its usual tests now before being returned. I particularly like this watch, its a classic watch that has stood the test of time, and as far as im aware, other than the 321 they are re launching, the only movement Omega currently use that doesnt contain the Co-Axial escapement inside it. Im not sure there will ever be a more iconic watch.

Thanks for reading.

The Watch Professional

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