There is this part of the clock and it breaks a lot and I’m learning how to fix it and I fixed it once on a clock and I really hoped I wouldn’t have to do that type of fix ever again. And now I have to fix it a second time on a different clock but this one is a lot harder. Also if I ever design clocks I will avoid making this part at all costs because it is evil.
Winding a clock – it’s something we’ve all said (probably?) and something we all know about… sort of. We wind it so it runs, right? And it doesn’t run when we don’t wind it? Well, what is it that you’re winding?
A spring! (duh) You are creating potential energy by tightening the spring with your key (or your hand, or a pair of pliers, or tweezers, or chopsticks if you’re really desperate). Below is a picture of a small wall clock spring disconnected from all gears and shafts and other clock parts.
Winding the spring makes the coil tighter and tighter. The spring drives what is called the time train; the train of gears that connect the spring to the central axis of the clock. In short: The spring wants to unwind, it tries to unwind, it tries to move the gears in such a way that would run the clock clockwise, and the gears (and the unwinding of the spring) are slowed down by the escapement, which I have briefly written about in the past. The progression from spring to central axis is called the time train because it is the train (like a chain) of gears that causes the clock to move forward.
So where are the drawbacks? Well there are two that I know of: one major design flaw and one major annoyance as regards clock repair.
The major annoyance? Holding a spring in place is hard. *cue whining voice* When you’re trying to get all the gears to line up with the top and bottom of the mechanism case and you have a spring that wants to literally spring out of place, it is difficult to keep everything from exploding every which way! Note below how my thumb is turning white from exertion. For accuracy imagine it trembling and me making annoyed “grr” sounds in the background as I try and hold the spring in place long enough to get the back of the mechanism screwed on (and I guess, uh, take a picture?). For those curious, this is the 1930s Lux Pendulette that I worked on a while back.
Oftentimes you can use a spring clamp to hold the spring in a tight circle. Unfortunately on small clocks spring clamps just aren’t small enough. So that’s the annoyance for clock repairists (repair persons…?). What about the design flaw?
The parts I’m going to show you are from the German porcelain clock shown below, but this is by no means the first time I have faced this. Last time it was a simpler fix, but this one I think is going to take some ingenuity.
I purchased this clock on eBay for $19.95 + $4.00 shipping. I guess I was feeling extravagant that day. Woops! In any case, I still really like the clock. 🙂
So here we are. The minute hand moves the hour hand, which is always a good sign – it means that the gears are moving correctly inside, at least for the most part.
After removing some pieces I was able to clean it off a bit and start putting the gears back in. As usual when putting a clock back together, the spring is the hardest part.
But before we get to putting the spring back in, there’s one thing I have to fix. You see, as the spring is wound (when the key is winding the clock) there is a locking gear on the face of the spring gear that holds the spring from unwinding (assuming both ends of the shaft are fixed). It is shown below.
Okay so it’s hard to see because its brass on brass, but there is an inner gear with angled teeth that clicks past the grey metal piece as you wind the spring. This is meant to be attached to the spring. For a similar picture taken of the inside of my Ansonia Wall Clock see below.
In the picture above, note how tension is holding the angled inner gear in place? That prevents the spring from unwinding. The pictures below show the opposite side of the the spring gear, including the spring shaft.
The above two pictures are of the other side of the spring gear, the side with the spring shaft that is turned by the clock key. In this case the shaft is threaded like a screw, so it is meant for some type of knob to go there instead of having to use a key. This makes sense since the clock doesn’t have any holes on the dial to allow for a key to turn the spring shaft. It’s pretty normal to see this on smaller clocks, likely because a hole for the spring shaft on the dial of the clock would take up too much space on the dial.
The knob is missing in this case but should be easy to find a replacement for. In the above image, look at the discolored square in the very middle picture, along the central axis of the shaft. A better picture of that square is below.
Sorry for the resolution – all of my pictures are on my iPhone 6, and though the camera is fabulous I am not the world’s best photographer. It doesn’t help that the pieces I’m taking pictures of are smaller than my thumb!
Anyway, the above picture shows that square again – it is protruding from the wider part of the spring shaft. It is, in fact, a hook! A very, very small hook (2 mm across, <2 mm deep approximately) meant to hook onto the inside of the spring. I’ll show you the photo of the spring one more time. This time look at the very inner coil of the spring and look for the area where the hook would go.
Do you see it? Now is it any wonder that the hook keeps falling out of that?!
“So Margaret,” you say, “You claim to be a budding horologist. Surely you have thought of some simple yet ingenious way to solve this problem?”
Okay so I do have a plan but no promises on it working out. I’m starting with a few facts.
- I cannot make the hook bigger
- I cannot make the spring easier to hook onto (I did try this)
- I need the hook on the spring shaft to hook onto this spring
- Super glue is not a real fix (in this situation)
So I decided *drumroll* …to file down the shaft so it is thinner. If I make the shaft smaller in radius then the hook will stick out further, thus effectively making the hook longer. Ideally I can also file the shaft in such a way that the hook hooks more securely.
Luckily, I happen to have a set of 12 metal files of assorted shapes! What, you mean you don’t?
So here I am, filing away. Dreaming of next week’s Date Night and pondering whether being right twice a day is, in fact, enough to get by. I would tell you about the big research project I have coming up but unfortunately it’s still a secret. 😉 I’ll be sure to let you know how the filing goes – if it’s anything like the tips of my fingers and fingernails, I’ll be making progress in no time. For breaks in-between filing I have been working on some light reading. Thanks for reading my “very very very unique” (true quote) blog and I hope to hear from you in the comments section below or in Contact!