Adjusting a 1913 Illinois 69 18s Pocket Watch to 6 Positions: Big is Beautiful

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After working on a couple Elgin watches, as nice as they are, it’s time to get back to basics. My unseemly stash of Illinois watches has been glaring at me, demanding some attention and implying that I need an intervention for compulsive hoarding.

This one is a big fellow, a beefy 18-size pocket watch. It’s a 17-jewel Grade 69 from 1913, but it looks older than it is. Illinois made full-plate 18-size model 6 pocket watches well into the 1920s.

These 18-size watches are enormous. Here’s this watch compared to a 16-size Bunn Special and a 12-size Santa Fe Special. The 18-size watch is much bigger relative to the 16 than the 16 is to the 12.

This 18-size watch is about as thick as the other two stacked.

Sizing up the Watch

I found this watch on eBay, the wellspring from which vintage Illinois watches flow. It was greasy but otherwise ticked.

Before adjusting, it’s worth sizing up the watch to find good and bad omens. We have several good omens: the general high-quality of Illinois watches from this period, the good jewel count (17), and some adjuster-friendly features (micrometer regulator, mean-time screws on the balance arms).

But disassembly revealed some bad omens. Two of the balance screws were roughly filed. This ranks among the very worst ways to remove weight from a balance screw. Notice that the screws were filed without regard to the position of the screw slot. One even has some of the slot filed off. Yuck.

Another oddity is a missing roller jewel. The roller jewel has been replaced by a brass pin. The pin has a roughly flattened face, sort of like a D-shaped roller jewel would. Clearly, someone couldn’t be bothered to track down and replace a roller jewel. It’s hard to say how much this will hurt the watch’s timing, if at all. So I guess this is technically a 16-jewel watch.

Finally, someone has been adjusting the balance endshake by chiseling into the bridge. If you look where the balance cock would go, you can see that it is dimpled and sanded down. At one point, someone chiseled dimples to increase the endshake. And later, someone scraped those dimples off the reduce the endshake. This shouldn’t affect the timing, but it’s a sign that someone with low standards worked on this watch in the past.

As an aside, if you look closely you can see that the balance wheel has lightly scraped a circle into the bridge. The wheel must have been riding low for a long time.

Cleaning and Oiling

No bugaboos jumped out when cleaning and oiling the watch. When taken apart, the watch shows its age. The winding and setting area is heavily worn.

After getting a new white alloy mainspring and fresh oil, it ticked right up. I demagnetized it for good measure and let it run for a day to settle in.

Adjusting the Big Fellow

This watch kept pretty good time right off the bat. Here are the rates at full wind.

Keep in mind that pendant right and left are defined from the dial side, but we’re looking at the watch from the movement side.

The amplitude was excellent: over 300 in the dial up and dial down positions, and over 250 in the vertical positions. After running 24 hours, the dial up amplitude was still over 300.

The watch is running fast, but all the rates are pretty close together. Frankly, you could stop here and be happy with the watch. It’s rare to see such close rates without any tinkering.

But the largest error is in the most important position. For a pocket watch, the big 3 positions are dial up, dial down, and pendant up. The largest error should be elsewhere, ideally in the 6th position (pendant down).

I’d like to adjust the watch so that the dial up position is closer to the dial up and down positions. It will be more accurate when in actual use, when it is mostly be pendant up and dial up or down.

We naturally turn to dynamic poising. As explained in our series, we start by running the watch at low amplitude. This magnifies the poise errors in the balance wheel.

Here are the rates at a low amplitude (around 160 degrees).

The wheel is heaviest in the fastest position, shown in red. This watch runs fastest in between pendant right and pendant down. When in this position, the spot directly below the balance staff is the heavy spot.

For the nuts-and-bolts of how to do this, have a look at all the dynamic poising posts and our step-by-step Burlington post.

For this watch, we would improve poise by adding weight. Remember, when the watch runs fast dial-up, add weight; when it runs slow, remove weight.

So we delve into our stash of timing washers. I picked a washer rated at 1 minute for a 16-size watch. Not much weight is needed, and this washer is relatively light.

I put the washer under a screw exactly opposite the heavy spot. This should even out the balance wheel.

And the result? Here are the final rates after the washer and some tweaking of the regulator.

You can see that the rates have “rotated” around the wheel. The pendant up position is now very close to the dial up and down positions. The watch now keeps its best time in the major positions. The largest error is now found pendant left, followed by pendant down.

With more adjusting, I could “rotate” the error into the pendant down position. But the rates are very good, and I don’t want to do the light filing of balance screws that would be required. For the watch’s age, grade, and condition (e.g., brass jewel pin), these are great rates.

The Case

This watch came with a swing-out case. The movement is locked into a hinged ring that swings into the solid, cupped case back.

The typical pocket watch case—a movement locked into a frame that is sandwiched between a crystal bezel and and case back—is more convenient in some ways, but it also has more seams for dust and lint to get into. Swing-out cases are more tightly sealed—or so the theory goes.

The case is a humble nickel case. I dig these cases because they can be polished to a freakish shine. After cleaning and polishing, all that was left was a new crystal. Glass crystals should be set with UV glue, with cures quickly in this infernal and otherworldly UV lamp.

Coda

This watch looks great and is running well.

I’ll probably carry it to work for a few days and then return it to the wellspring of eBay. I like these large watches but find them a bit too big to carry comfortably, and this watch deserves a more appreciative home.