On My Bench - Seiko 6139-6002 - The First Automatic Chronograph

JimInOz

Update - Project on hold for a few days.

While on eBay ordering parts, I happened to browse the sellers other listings (who doesn't do that 😁) and noticed that he had an upgraded/improved movement holder for the 6139 so I ordered one.

JimInOz

I'm sure @Archer can answer that much more eloquently and factually than me, but here I go.

Some simple movements require a special holder with a spigot in the base to support the shafts of the movement when pressing hands on to those shafts.

With a chronograph, the support function is also important, but the other reason is to enable starting and stopping (and holding) the chrono mechanism so that the hands can be fitted in their correct position. It also allows testing of the movement with hands prior to re-casing.

I only have a few, mainly the 3D printed type for Seiko chronographs and a proper one for 7750s.

Archer

Movements come in different sizes, so some holders are geared towards a specific range of sizes. Smaller holders work better with smaller movements and larger holders with larger movements. Here are some of mine:



When working on the wheel train side of the watch, a standard Bergeon 4040 movement holder (mine is in the second row from the top, and is the middle holder) works for most watches. When you are working on the dial side, and in particular when you are installing hands, the jewels need to be supported when pressing the hands on. This style of holder tends to be round and of course not adjustable for the diameter of the watch, so you can see many of those in my photo. You will see in many of those there are supports coming up from the bottom of the holder, and those can be adjusted to support the jewels where the hands are being pressed on.

I also have several variations of chronograph movement holders shown, and those can actuate all aspects of the movement they are designed for. For example the one for the regular Speedmaster movement (321, 861, 1861, 1866) is the very first one in the top row on the left side. You can see the two long pushers out one side that are for stopping and starting the chronograph, and the two smaller pushers on the opposite side are for actuating the moon phase and date functions on the Cal. 1866 moon phase caliber. All these need to be actuated during the service process for testing purposes and setting on of hands.

There are also holders there for specific tasks related to servicing co-axial watches, since the escapement must be cycled during the lubrication process, and these are very caliber specific.

You tend to gather these from various locations, and the reason I have some duplicates is that I recently bought some items from a watchmaker's estate, so you end up with spares, which is not a bad thing.

In the end, these are tools needed to do the job properly. They can range in price from just a few dollars to many hundreds of dollars. I won't add up how much I've spent on them...but it's a lot....but they all make the job more efficient and help prevent problems in servicing.

Cheers, Al

JimInOz

Woo Hoo......parts are here at last .

Now I can get the plate and bridge ready to re-assemble.
As soon as I put jewels in for the barrel arbor.

First thing, after selecting the right size pushers and anvil, we remove the bushing from the barrel bridge.

And here it is, to be replaced by a jewel.

Sorry, no pics of setting the jewel, it took both hands and a lot of focus, but here is a pic of the jewel in the bridge.

That'll be all for the moment, It's almost beer o'clock here so time to stop work and relax.

PS: And to answer the question "why are you wearing gloves/cots?".
Have you seen jewelling / staking sets that have been handled by sweaty fingers?