Welcome!

Classic watches, watchmaking, antique tools, history, vintage ephemera and more!

Learn about mechanical timepieces and how they work, the history of the American watch industry and especially all about the Elgin National Watch Company! Check back for new content daily.

Although this is technically a blog, the content is not generally in a time-based sequence. You can find interesting items throughout. Down the page some is an alphabetical word cloud of keywords used here. A great way to dig in is to look through those topics and click anything you find interesting. You'll see all the relevant content.

Here are a few of my favorites!

There are some large images on some posts, so that might impact your load times, bit I think you will find it worth the wait. Thanks for visiting!

Waltham Bond St 1888 Model

Here are the components of Waltham's motor barrel. This same design is found in many Waltham watches, or various sizes.

The two halves do not fix together, they move separately. The arbor turns freely in the outer half (right) and sits in the square hole in the lower, inner half (left).

This watch, as found, was missing a spring in the winding setting mechanism. It was also missing the screw that holds the spring. It took awhile to find these parts.
 Here are the missing parts.
And here are the missing parts in place.

These old Walthams have a really flaky and difficult design for the winding/setting parts, or keyless works. Unlike other watches of its era (which are "negative setting"), the "snapping" function is in the movement, not the neck of the case (so "positive setting", as in modern watches). It's really difficult to get the stem in, and parts are extremely prone to wearing out and breaking - which is probably why this watch was missing its setting spring. Also, these have to go with a specific watch case.

Anyway, there's a problem here. In this photo, the clutch is outward in its winding position. The stem is snapped out.

The way this winding/setting mechanism works, there is a clutch that slides inward and outward. Outward, it engages a pinion at that end that winds the watch. Inward it engages a gear that turns the minute wheel to set the hands.

A lever is moved when the stem snaps in and out. The lever pushes a spring back, to push the clutch in, when the stem is snapped out. When the stem is pushed in, the lever release the spring and the spring pushes the clutch out into winding mode.

Or it is supposed to.

In this picture the stem is in. But the spring does not push the clutch out far enough. There is a visible gap between the clutch and the pinion. The watch will not wind.

So what do we do?

One thought is to use a smaller stop screw - the screw that the inner part of the lever bumps into to stop the snap out, and push the spring in. I checked and this would work. I could have used the lathe to make the screw head a hair smaller in diameter and the the spring would the do its work.

There's three problems with these solution though, 1) never alter existing parts to make a replacement part (the spring) work. And 2) never do anything that is not reversible.  Strictly speaking this is reversible since the screw could be replaced, but still...

Perhaps the worst problem though is that then the stem would actually snap out just a hair further. Although that's a small change, it's a can of worms I want to avoid. Who knows what happens next, the stem has to be shortened so the crown doesn't stick out too far?

So I dug through my Waltham parts and found a few pieces set aside from this grade. It is the same bunch of stuff that didn't include the missing spring that delayed this project (aside: when you have a pile of watch parts from an estate or something, the most needed parts are less likely to be there because those are the parts most often needed, so those have already been used. If you want to know what parts in a watch are reliable and durable, check the spare parts that you have to most of). My parts for this grade did include a clutch. Although this clutch looks just like the one in this watch, I know from past experience that Q/A in the 19th century was not what it is today. Old parts are very often slightly different from each other.

I installed the alternate clutch, and as you can see here, for what ever reason, it fully engages the winding pinion, just as I'd hoped. I suppose it is just a hair longer, or maybe the grove is in a little different place. It was made on a different day, and maybe the machine got set up just a little differently, and it works in this watch.



Ticking away!

Post a Comment

Click "Older Posts" just above for more, or use the archive links right here.

Blog Archive