COVID-19 "Lock Down" Project - 1981 Seiko 7009-8210 Restoration (Part 5)

by Darren Thomson
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19 Apr, 2020
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Part Five - Movement assembly (gear train and winding mechanism)

Ok, time to start re-building the movement. We'll start by making sure that everything is "operating theatre clean" (even a tiny hair in the wrong place at this stage will cause problems later) and then position the wheels of the gear train into their respective jewelled holes.

In the picture above, we see the mainspring barrel (sometimes referred to as the "1st wheel") on the far right, the escape wheel on the bottom left of the train and then the other parts of the gear train connecting these. Positioning these wheels correctly can be tricky, they are obviously tiny and their positions have to be perfect or we can't progress to the next step.. securing them with a "bridge"....

In this picture (above) we can see the main bridge sitting on top of the gears. This has to be positioned very carefully before it is screwed down. Each gear has to sit perfectly in both its bottom and top jewel holes or nothing will work. When i first started watchmaking, placing bridges over multiple gears almost turned me off the hobby.. It's one of those jobs where you need 6 pairs of tweezers at once to get everything in place. It gets easier with practice.

With the main bridge on correctly and screwed into place, we can turn our attention to the ratchet wheel and winding mechanism. These get fitted onto the main bridge. On these Seiko watches, a proprietary Seiko winding mechanism called a "magic lever" is used. I love these things, so clever.. Check out this video showing the "magic lever" in action..

A simple little device but very reliable and efficient. Regardless of the direction of travel, the little "paws" turn the ratchet wheel and wind the main spring. When Seiko first came out with this concept in the 1960's, most automatic watches could only wind "one way". Obviously, the gear that I am manipulating here will eventually get connected to a rotor that will spin when the watch is moved around.. That comes later.

With the gear train, bridge and winding mechanism in place, I can install the pallet fork and its bridge..

Another fiddly job getting the pallet fork into its jewel holes.. Kind of hard to see here but the little square-shape purple jewels that you can see here on either arm of the pallet fork (at 10 O'clock in the picture) swing backwards and forwards, interacting with the escape wheel (to their left). The other end of the pallet fork (in the middle of the picture) will swing and knock the balance spring one way and then another, like a pendulum. This is the "tick tock" that you hear in a mechanical watch. I'll shoot a video of this happening later.

That's all for this part, next we'll flip the movement over and put the "keyless works" together..

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"Lock-Down" Project - 1890's Waltham Pocket Watch (Part 10)

by Darren Thomson • 15 June 2020

As can be seen here, this old watch's case has seen better days. On the upside, it is made of solid Sterling silver and experience tells me that I might be surprised at how nice I can get this looking with a little time on the polishing machine.

... And, sure enough, 20 minutes of careful polishing accomplished this..

"Lock-Down" Project - 1890's Waltham Pocket Watch (Part 9)

by Darren Thomson • 8 June 2020

After some serious rooting about in my various parts drawers.. I found a bag..

"Lock-Down" Project - 1890's Waltham Pocket Watch (Part 8)

by Darren Thomson • 4 June 2020

We are almost ready to put the dial and hands onto the pocket watch but before that can happen we need to clean the dial and install the "Motion Works".

Examining the back of the dial reminds us, once again, of the general quality of components used here.

"Lock-Down" Project - 1890's Waltham Pocket Watch (Part 7)

by Darren Thomson • 1 June 2020

All of the major functioning parts of this pocket watch's movement are now in place and functional. It's time to see if the old girl has life in her. The project pretty much ends here if there is a major issue with the balance or the mainspring (still un-inspected internally for reasons stated back in part 3). There is almost no chance of finding replacement parts for this piece so it could get consigned back to the spares drawer if this doesn't go well..

A careful wind of the mainspring (feels solid and free-moving - click is working well). And....

"Lock-Down" Project - 1890's Waltham Pocket Watch (Part 6)

by Darren Thomson • 28 May 2020

With the train of wheels now installed and working, we can turn our attention to the Pallet Fork and its bridge and screws. Here they are..

"Lock-Down" Project - 1890's Waltham Pocket Watch (Part 5)

by Darren Thomson • 24 May 2020

For me, this is the most interesting part of the build, certainly from a mechanical perspective. This is where we get to see how the power delivered from the mainspring travels through a train of wheels to deliver suitable energy to the balance.

Here are the components at play for this stage..

"Lock-Down" Project - 1890's Waltham Pocket Watch (Part 4)

by Darren Thomson • 23 May 2020

With the barrel and winding system now in place, we would normally secure them with a bridge. In this case, though, it looks like the main bridge has to go on after the rest of the gear train is assembled. So, for now will just make sure that the centre wheel is properly secured into the bridge and test fit the whole thing.

Having inspected the main bridge and centre wheel.. I've found out where that little pinion gear referenced in part 3 lives..

"Lock-Down" Project - 1890's Waltham Pocket Watch (Part 3)

by Darren Thomson • 20 May 2020

Now that we have everything clean and checked over, its time to starting putting the 130 year-old movement back together again. Honestly, anything could happen here and, on a job like this one, I won't even bother to start thinking about the watches' case, dial and so on until I know that I can get the movement ticking again. The good news is, it wont take long. An old pocket watch like this is quite a simple mechanism in comparison to modern wrist watches. For one thing, we have less parts to worry about (no calendar, no "keyless works", no automatic winding mechanism...).

We'll start, as with most watches, with the barrel which houses the mainspring and the associated "click" mechanism (the ratchet that stops the barrel and mainspring from un-winding under tension and the thing that you hear when you wind a watch). Here are the components for this part of the build..

"Lock-Down" Project - 1890's Waltham Pocket Watch (Part 2)

by Darren Thomson • 18 May 2020

One benefit of buying a "bag of bits" is that I can skip the initial strip down of the watch. Of course, the downside here is that I really don't know if anything is missing or broken. So, the first thing to do is clean everything up and get 100 years worth of grime off of the components and then inspect everything carefully.. In particular the hairspring, gear teeth, mainspring & jewel settings..

The hairspring is by far the most sensitive watch part. This one looks very dirty but it has a good spiral shape to it, with no parts of that spiral touching other parts of it (which is a common cause of "fast running"). The Waltham spring also has a "Breguet Overcoil" design. This is a specific hairspring design invented by Abraham-Louis Breguet (important watch dude) waaaaay back in the 1700's and, essentially, allows for better performance of the hairspring through varying mainspring tensions (watches tend to slow down as a mainspring loses power and go faster when it is fully wound).

I'm going to clean this movement using my ultra-sonic cleaner and, to do that, I like to mount the balance and hairspring in the main plate to keep it safe during cleaning..

"Lock-Down" Project - 1890's Waltham Pocket Watch (Part 1)

by Darren Thomson • 15 May 2020

Well, my last little side-project got completed and we are still in "semi" lockdown in the UK so I thought i'd turn my attention to something else that I've been meaning to get to in the workshop.

As a watchmaker, one thing that you will certainly accumulate in time is PARTS. They come from watches that never got repaired, over-ordering when you only need one of something and a seller will only sell you 10 and, frankly.....Well, I don't know where many of them come from... but come they do. Here's a sneaky peak at ONE of my many "parts drawers"..