Tuesday, November 15, 2011

My First Teardown

IMG_0218.jpg

My very first Unloved Watch is a hand-wound Citizen about as old as I am. Going by the information I found about Citizen serial numbers here, it was manufactured in August, 1971. It has a stainless-steel cushion case, blue enameled dial with a subtle sunburst, lumed sword hands and dots for the hour markers, with some yellow accents. I bought it at a flea market. It ran, barely, but was really badly abused.

The hour and minute hands didn't line up. When the hour hand was on the hour, the minute hand was around 20 past.
There was a lot of friction when turning the crown. This, in fact, made it very difficult to set, especially because the crown is rather small, more like one from an automatic than a hand-wind watch. Eventually I managed to unscrew the crown when trying to turn the hands forward, and then something got knocked loose and the clutch wouldn't catch at all, which also stopped it from running. I know, shouldn't have twiddled it so much.
The crystal was almost matte with scratches, and there are a few very very small cracks around the edges. The case was very badly scratched as well.
The movement was a little loose in the case. It was possible to hear or feel it rattling around when handling the watch.
The watch ran rather badly. The balance wheel does go back and forth, but at relatively low amplitude, and you have to wind it up a fair bit before it starts.

A perfect candidate for a novice wannabie watch nerd to experiment on, in other words. Or is it?
I would have had it easier if I picked another watch for my first project. For one thing, the movement is pretty small, at around 25 mm across—11 ligne or so, I didn't measure it with calipers. Many cheap Swiss movements are 5 mm bigger, and pocket watch movements much bigger than that. And for another, the date complication hides a quite a few tiny parts, including a J-shaped spring that was a real bastard to get back in.
At this writing, I'm maybe halfway through working with this one. I ordered an ultrasound washer, but it hasn't arrived yet, so I haven't even attempted cleaning or oiling it. That's up next. At this time, I figure the odds of the watch surviving the experience is maybe one out of four. I have successfully disassembled it almost down to the component parts. I did not remove the cannon pinion, nor did I disassemble the balance cock/balance wheel/balance spring mechanism, and the mainspring barrel didn't easily unscrew from the barrel bridge, so I let that sub-assembly alone as well. But I did get down to the pillar plate, on both sides of the watch.

Preparation

I followed the excellent, excellent instructions here, with some more reference to pictures here. They worked to a T, with only a few minor differences in the order in which the watch came apart. Additionally, I thought of taking a photo of every stage of disassembly, which was a real life-saver of an idea. I would have had real trouble getting everything back where it came from without those pictures for reference. I'm publishing most of them here in case someone else embarks on a similar project and finds them useful.

For tools, I used an inexpensive watchmaker's toolkit by Anchor. I figured that since I don't really know what I need, I'll follow my camera buying tactic of first buying something that I expect will get the job done somehow, and then, if and when I know my needs better, I'll complement it with better-quality gear I use frequently. It's getting the job done fine so far. In addition to the tools in the kit, I bought some oil needles and oil, which I haven't used yet, and a movement holder, also from Anchor.

Two other things made my life enormously easier: my Canon S90 digital camera, which is small and easy to use and has enough macro capability to get my reference photos, and a desk lamp designed for this kind of work—I happened upon that completely by chance, although I was looking for a desk lamp. It has a circular fluorescent tube, with a big magnifying glass in the middle. It is absolutely brilliant, makes everything way easier, not least taking those reference photos.

I'm not going to give instructions on how to do the teardown; I couldn't possibly add anything to the page I referenced above. What follow are photos and my impressions of how hard it was, what turned up, and what surprised me.

IMG_0230.jpg

The Teardown

The first thing to do was to get the movement out of the case. I unscrewed the back with a case opener, pressed the stud next to the crown and stem, and popped out the stem. The movement dropped into my hand when I turned the case over. Then I removed the hour wheel and popped it into the holder.

IMG_0239.jpg

What a nice-looking movement! Cheap it may be, but the visible parts are beautifully machined, with those rose-colored jewels in their golden bushings winking back like... well, jewels, I suppose.

Then I removed the barrel bridge. The mainspring barrel came right with it. I had to slide it sideways from under one of the train wheels, using those nice sharp tweezers. I also put back the stem to keep the winding pinion and clutch wheel in place.

IMG_0243.jpg

Next up was the train bridge, revealing the train gears.

IMG_0244.jpg

The gears lifted out easily enough.

After that, the bit I figured would certainly destroy the watch—removing the balance cock, balance spring, and balance wheel assembly. It turned out not to be all that difficult after all; I just slid half my tweezers under the balance wheel, and picked up the whole thing so that the tweezers held it together. Then turned it around and put it in my parts tray. That's a fancy name for a translucent plastic box with little compartments, I bought it at Clas Ohlson for a euro or two.

IMG_0252.jpg

Next up was the pallet fork and arbor. Those things are tiny! I was sure I'd never be able to get them back in, but getting them out was easy enough.

IMG_0253.jpg

The last bits on this side of the watch are the bridge that holds the cannon pinion (cannon bridge?) and the wheel under it, and finally the center wheel. Still easy!

Stripped Down

The Date Complication

Then I put everything back together again. It didn't run, which didn't surprise me. I was happy enough to have put everything back more or less in the right place, with no pieces left over. In fact, I was starting to feel a bit cocky, and flipped the movement over, figuring I might as well check out the date complication while I'm at it. Ouch.

There's a reason those guys recommend a plain movement with no complications for starters. A pocket watch movement, preferably, as it's a sight bigger. I don't always take advice well.

IMG_0255.jpg

The movement doesn't look quite as nice from this side. The plate covering most of the movement isn't machined; it's just stamped and, I think, nickeled. Looks a bit cheap. So I removed it.

IMG_0258.jpg

This photo isn't the one I took after removing it. See that little J-shaped spring holding up the claw that keeps the date wheel in place, at around 5 o'clock? I only found out about that after I'd placed the plate in the parts tray. Also, the dark-gray gear at 7 o'clock had stuck to its underside, and I only noticed it when it dropped off. I had no clue where that little spring went, at first.

Anyway, the two wheels at bottom left lift right off. Then I removed the bridge covering the winding pinion and clutch.

IMG_0263.jpg

The last bits to come out where the wheels that set the time, and the clutch itself. I didn't take a photo of the movement after I removed them, but I did get there. There's another nasty little U-shaped spring under the clutch; you can see it in the picture. That helped me figure out where the J-shaped one fit!

Lessons learned

I had to put the movement together three times before it finally ran. There were three hard parts.

The first hard part was getting those little J and U-shaped springs on the face of the movement back where they belong. The clutch spring wasn't too bad; I just held it in place with one hand while screwing in the clutch with the other. I eventually got the date one back too, by placing them like in the photo, then sliding the date wheel over them so that it simultaneously held them down and put it under tension. Took me a few tries, but I eventually succeeded.

The second hard part was the pallet fork and arbor. It was hard to tell when it was properly seated, until it finally went back, at which point it was perfectly obvious. When it wasn't in properly, the entire movement was locked up -- nothing moved at all, even the balance wheel.

The third hard part was the train bridge. It wasn't obvious to get all three staves in their jewels, and the gears to mesh. When things weren't in properly, everything moved rather too well; when I turned the crown, the train spun madly.

And one part that wasn't exactly tricky but a bit puzzling at first was the assembly of the winding pinion and clutch wheel, and how they slot with the clutch. The "finger" of the clutch goes in the groove of the bigger cylindrical gear; the finger moves it back and forth to engage the winding pinion or the setting gears.

I'm pretty satisfied with my tools and my general setup. I think I might eventually buy a better movement holder and screwdrivers; one of mine is magnetized which is really annoying because parts cling to it, and the movement holder isn't really very precisely machined, which makes it unnecessarily tricky to get the movement to stay put in it. Not showstoppers, but annoying enough that if I do take to this hobby, I will probably upgrade somewhere along the line.

Eventually I did get everything back in and discovered that I was able to wind the watch and set the time again. I was quite certain I'd screwed something up, so I was almost shocked when the watch came to life when I wound it up a bit. It doesn't run any better than before, but as far as I can tell it doesn't run any worse either. Who knows, maybe it'll even survive my tender ministrations.

Next up is cleaning and oiling it properly. I figure the biggest risk there is losing some parts—they fly around easily, and I had about three very narrow escapes so far. I may not be so lucky next time, even if everything else goes as well as until now.

4 comments:

  1. An inexpensive and easy way to help prevent losing parts is to take something like an old bed sheet (preferably white) and fix one side to your clothing, midsection-ish, and the opposite site to your table/workbench. The idea is to form a catch that will prevent parts from getting lost between you and your workbench. Putting a white sheet down on the floor, under your workbench and chair, is another good trick - easier to find parts when they do escape that way.

    ReplyDelete
  2. Hey, what an excellent idea. I'll do exactly that. Thanks!

    ReplyDelete
  3. Hey Petteri,
    My name is Rob from WUS, otherwise known as OuttaTime. If I might make two suggestions to make life easier:
    While you are looking at the movt from the back, with the caseback off, it is critical to 'let down the power', that is, using the stem, advance the winding so the click moves and then push the click out of the way with a tweezer or pick and gently allow the stem to rotate as the mainspring unwinds. You don't want any power to the train when you start disassembly. Some watchmakers do this with the movt out of the watch, but it must be done before taking plates or especially the pallet fork out.
    Another procedure that is worth its weight in tiny gold springs is to sharpen a pegwood to a point on one end, and a chisel shape or wedge on the other. This must be kept clean, and well shaped, and you use it to hold down tiny J shaped springs as you install the or the part they act on. The U-shaped one under the sautoir, or setting lever spring/cover, is the yoke spring, and the other one is the date jumper spring, which acts on the date jumper, or pawl. I really enjoyed your blog, the style and pics are great!

    Rob

    ReplyDelete
  4. Rob -- Thanks! I already knew about letting down the mainspring; it was in the basic how-to I was following, but those suggestions for pegwood are great. I have some, but I haven't figured out many things to do with it. A wedge-shaped pegwood would've made the spring thing much easier. I'll do that next time.

    ReplyDelete

Note: Only a member of this blog may post a comment.