On The Bench Today, Job Numbers 180057 and 180055

 The Aurora watch, job number 180057, has not been running reliably and is hard to wind and set. I think the main reason (there may be more than one) for its not getting through most 24 hour tests is that it is just not fully wound. It's really rough.

The trouble is that all the parts are quite crude and just barely mesh, push and pull the way they are intended to.

While going over the keyless works again, I thought I'd also mention the regulator. Notice the index of the regulator in this first image. There is a big screw with a crow slot. This screw is not holding anything, The index is held in place by the two small crews at either end. The big screw in fact turns freely. What is it?

Well it's part of a micro-regulator set that is not there. It's missing a sliding part that would fit between the index and the screw. This part would have teeth on one side so that turning the screw would cause it to move from side the side, taking the arm of the regulator with it.

The thing is though, that I think they sometimes shipped them like this, with the part missing. I have seen others missing this part, having no marks or other signs that it was ever there.  If you do an image search and look as close as possible at other movements, a lot of them look like this. This is personal conjecture of course, but when you work on these early American products they really feel like the products of factories that operated in a pretty frantic, ad-hoc manner.

Aurora used, I don't know, 5 or 6 regulator designs, and held valuable patents on them.

On to winding/setting...

The gears on this really grind. They just don't fit well, and it shows in the wear on them which only makes it worse. I don't want to loosen the cannon pinion to make it easier to set unless it's the only option. The first thing to try is some oil along the cannon pinion's grooves. 

Also, one thing I hear sometimes about lever set movements is that they do not pop into setting mode easily. On a modern watch you snap the crown into setting and it is in setting, instantly.

These are not modern watches.

The first image shows the lever tucked in. The movement is in winding mode. Turning the crown  turns the ratchet wheel just outside the top of the image and winds the mainspring.

This second image is what is looks like when the lever has been pulled out. Pulling the end of the lever away allows a cam to in turn allow the small idler gear to pivot (the cover over all this, the part that pivots, is called a "vibrating arm"). The gear then engages the minute wheel (removed in this image) to set the time - or well, it almost does. Actually, the pivot is not quite far enough.

In this state, turning the crown clockwise will do nothing. Setting is not fully engaged.

A small turn of the crown counter-clockwise creates a little torque and pivots the arm all the way. Note in this image how the cam has popped fully over the extended edge of the vibrating arm, forcing the setting gear further over and engaging the minute wheel (now in place).

All this is governed by two springs, which are visible in these photos. One pushes the vibrating arm into winding position when the cam is out of the way (lever in). The other pushes the cam into setting position when the end on the lever is out of the way (lever out).

These springs work against each other so their relative strength is important. They are also 100 years old. And on this watch one closely resembles a bent piece of wire which the other looks like part of an old mainspring. If I saw these in an Elgin, Waltham or Hamilton, I'd say some watchmaker of old had a broken spring to deal with and had done their best to rig something up.

So, long story short, yes these mechanisms can be a little sloppy. We do the best we can.

One last note about this watch, for today, It has a very heavy duty dust cover ring that slips over and around the outside to cover the space between the upper and lower plate. It's quite snug. This is a suspect in the watch stopping. I think it is putting enough pressure here and there to cause shifts in the plates, the pivots and thus cause gears and pinions to shift and bind a little. I am re-seating the cover to make sure I have it fully down. I'll also be careful not to over-tighten the case screws as that can sometimes cause the same issue. I'll leave them "just enough". A movement that runs fine not cased, but mysteriously stops when fully assembled is not uncommon.

On to this one...

Job number 190055 is one I thought was going to have a really nice result, once we found the needed escape wheel. Indeed, on the machine, it times not just well but dang near perfect with an extremely low beat error. It responded nice and smoothly to adjustment, just like it should. It's running great, or seems to be.

In practice it gains in the ballparks of 20 minutes per 24 hours. This is a mystery. I'll be checking a few things out later...

Job Number 180057, Part 3

I just couldn't get the winding smooth, and still set the watch OK, so I decided to see if I could find a replacement main wheel. Astonishingly, it was the 3rd or 4th one I picked up.

The old one doesn't appear all that worn, but the different one I piled out of the pile works a lot better.

I had to assemble the dial and hands twice. The click spring was interfering with the bottom of a case screw. The "keyless works" (winding/setting mechanism) in this watch is really something!

It's working though.

Job Number 180057, Part 2

This is part two of this post.

I went ahead and put the rest together.

The balance on this watch is good and it does run.

I didn't take photos of my first attempt to make the watch windable, but what I did was to place the washer over a steel block with a hole just the size of the horizontal part, the body, of the washer. Then I gave it a very light tap.

This bent the edges of the washer down a hair (a lot less than a hair actually) so it presses the main wheel down. This worked, to a point. I was able to wind it some so as to get the thing ticking.

However, as I worried, that also makes it too snug to easily rotate into setting mode, without loosening the screw a little. I need another plan.

I'm going to spend some time seeing if I can find another one of those mainwheels here someplace. It doesn't look worn out, but it's all so close that just a different part may work better.

Job Number 180057, Part 1

This watch is an Aurora Watch Company 18 size, 15 jewel movement, made about 1885.

First a few "before" images.

The first thing of note is how big, clunky and unfinished things are. This is typical of the earlier American watches. Making things with more machinery, and less hand work was new at the time. Parts tend to be well designed functionally, but rather crude, especially if you've been looking at Elgins, Hamiltons and like from later years.

A spring popped out of place when I removed the clamp over the ratchet. It almost looks like a piece of old mainspring some repairer hand formed as a kludge. It's not, this is a factory part.

It seems like many parts in the early American pieces were actually handmade. And their tools and machinery were all rather crude. All this must have improved extremely rapidly at the very end of the 19th century. It must have been a great time to be a mechanic.

 Huge bezels...

 Pretty dirty...

The serial number is stamped on a lot of the parts.

The parts above that hold the winding arbor go here. At first I thought one of the four screws was missing. Nope, it's broken off. Fortunately it was easy to get out and I found a suitable replacement.

Old style tangential, English lever escapement...

Notice this partial-round cut out in the ratchet clamp that fits the little curve in the end of that ugly setting lever spring, right at the edge of the plate.

Here's the other end of that spring.

It took me awhile to get this assembled with the springs in the right place.  Not easy...

Again, even just a few years later we see watches with a much more refined design.

My current issue with this watch is that the bevel pinion, part of the winding arbor, and the main wheel (the largest gear shown in this image) do not engage well for winding. The teeth on the parts don't look all that worn. There's just too much play in the main wheel, up and down. Everything is just sloppy.

I am not yet sure what to do. If I trim the underside of the washer a little so the screw goes down further, and holds everything tighter, that might work, But go too tight and it won't move.

I'm not getting as much done today as I usually do. I am going ahead and post this just so I have something to show for the morning. A couple days ago I was stung on the hand buy a bee (!) while working on our outdoor aviary. My right hand is a balloon at the moment, adding to the challenge of this watch project!

A Charles Stark Mystery Train

This unusual pocketwatch had an unusual problem.  This watch is an 18 size, 7 jewel movement labeled "Charles Stark".  More about that here...

At first this project seemed straight forward.  All the parts are here, nothing is broken.

The movement cleaned up well and ran.  Good end-shake and side-shake through-out, good pallet, everything was fine.  It timed well on the timing machine also, reading at less than +/- 30 seconds per day at 18,000 BPH (beats per hour).

My last step in watch testing is to run each watch for several days in various orientations; dial up, dial down, hanging, etc.  I didn't expect any issues with this watch.  But it turned out to be one of my more difficult and puzzling projects.

While the movement tested fine on the machine, it ran consistently fast, very fast, or so it seemed.

My first reaction was of course to recheck everything, especially the hairspring.  It was all fine.  I ultimately disassembled and reassembled this watch several times finding no problems.

Finally in desperation, I counted the teeth on the wheels, and the leaves on the pinions.

For a bit of background here, it may be helpful to refer back to this post on counting the train.  Watches operate by regulating, slowly releasing at a certain beat rate, a power source through a set of gears.  These gears, or wheels, have ratios such that hands attached to the right gears rotate at a rate we recognize in seconds, minutes and hours per day.  It isn't magic, it's mechanics.

These are the count values for this movement.

Great Pinion: 10
Great Wheel: 65
3rd Pinion: 8
3rd Wheel: 60
4th Pinion: 8
4th Wheel: 70
Esc Pinion: 8
Esc Wheel: 15

The 4th wheel's revolutions per hour is therefore:
( 18,000 * 8 ) / ( 70 * 14 + 2 ) = 68.57

The 4th wheel is the seconds hand.  This should be 60 revolutions per hour, one per minute!

But is gets worse.  If we calculate the rate of the center wheel:
(8 * 8 * 68.57 ) / ( 65 * 60 ) = 1.57

At 18,000 BPH, this leaves an erroneous rate of the center wheel, which is to say the minute hand, of 1.57 revolutions per hour.  That's +180.4 minutes per 24 hours on the hour and minute hands!  But that's only the beginning.  The error on the second hand is not relatively the same as that of the minute and hour hands.  In other words even if we did awful things to the balance wheel to shift the rate away from 18,000 BPH to the point where the main hands read OK, the seconds hand would go around a bit more than one time per minute.

This watch's train contains incorrect parts.

In fact, it contains more than one incorrect part.  The strange thing though is that this watch "ticks" fine - quite well in fact.  Because of the geometry of the way gears work, all possible combinations of tooth and pinion counts will not all run smoothly in practice.  They have to mesh well.  This is why any 18,000 BPH movement, with a seconds hand, will tend to have the same counts.  This movement's combination also runs fine at 18,000 BPH, but it is physically impossible for the hands to read correctly.

For comparison, here are the values of the train counts for a typical 18 size Elgin pocketwatch, non-slow beat.

Great Pinion: 12
Great Wheel: 80
3rd Pinion: 10
3rd Wheel: 75
4th Pinion: 10
4th Wheel: 80
Esc Pinion: 8
Esc Wheel: 15

Fortunately, this watch's train layout is very similar to other American watches or this size and era.  The height, the distance between the plates, is a bit atypical in places, but the layout is common.  It was a bit of work but I was able to swap to wheels with replacements having different counts.  The wheels only had to be altered a small amount for a good pivot size and for the height of the movement.

I replaced three wheels for an atypical count, but one that worked out to give the correct time readings at 18,000 beats per hour.

There's more about this mysterious watch here.

These additional images show the lever-setting mechanism.

Charles Stark

This is an obscure 18 size movement marked "Charles Stark", who was a major dealer out of Toronto around 1899.  

The 7 jewel, lever-set movement would seem to have been made by the short lived Aurora Watch Co., in the US.  As an aside, I'm not sure these qualify as a private label because it seems that Aurora only made movements for exclusive dealers in given regions.

However, this particular movement's design does not exactly match any known Aurora products.  The serial number also makes no sense in a context of Aurora products.  What is is this watch?

It is very, very similar to 18 size Walthams of this era. The dial side is different, particularly the ratchet, but just the same, it's obvious what the designers were looking at when them made these.

We see an English style tangential pallet, and other features typical of American products of the mid to late 1800s.

But the real mystery of this watch is the train.  Take a look here for more...