Modern Style Technical Diagrams of Vintage Watches

I'm sometimes asked if there are things like exploded diagrams of vintage watches. Usually there are not. There's reasons for that.

I remember once when I did not know anything at all about watches, and I mean nothing, my grandfather was showing me how things are disassembled and reassembled. I asked the pretty basic question of how he remembered where everything goes. He said, "well it only goes one way." Which is almost always true. But it wasn't until years later that I understood what he was saying, after reading some of the works of my grandfather's teacher, who was a well known watchmaker in his day. He advised that students should study and completely understand how something works before doing anything. What I realized is that the best way to know what's going on with all those parts is to fully understand how the mechanism works. Then the question doesn't even arise. 

It only goes one way.

Not a Good Day, Job Numbers 190031, 190026, 190030, 190042

Job Number 190031
Returned to me barely running, I found it to have been very strongly magnetized. That’s easy to fix, but it is still on the bench. I can not get consistent timing in any position. Some runs it’s fine, then the next day it will be 2 minutes off, no detectable cause.

Job Number 190026
Mysteriously arrived with the crystal off. It’s on its way back.

Job Number 190030
Arrived unable to go into setting position, sent back. I took the dial off, examined the setting/winding parts, found no problem, put it back together, works fine again just as it did when it left the first time.

Job Number 190042
This watch tested for 4 days with less than 1 minute of error. It’s on its way back reported to lose 10 minutes an hour.

A typical test period before I send watches back is five to six days, very rarely less. I wind and set them every morning, recording the times and error. I do this dial up, dial down and hanging pendent up. If I have to adjust anything, anything at all, I start the whole process over from the beginning. Many watches are tested for a couple of weeks. I keep testing them no matter how much the owner emails me. When I know someone wants to carry the watch, I often carry it myself for a day just to make sure. When watches come back, no matter what, whether I fix something or not, I literally triple the entire testing process.

Long before getting to practical testing, checking and servicing everything in a watch is a meticulous and time consuming procedure. There's dozens of things to inspect and test from the mainspring barrel to the escapement to the hands and every pivot, pinion and tooth in between. I don't skip anything, whether the watch is a complete wreak or near mint. After all that, all there is I can think of to do is the practical test of actually running a watch for days and days. When it's good, I send it back.

That isn’t good enough and I don’t know what to do about it. I don't know what else to add. I have been at this for 15 years but for some reason it’s worse than ever. I think I am going to give up this work.

Job Numbers 180045 and 180068, New Arrival

My first attempt to fix this sleeve is this hairspring collet tool. It's not intended for something like this, but it looks like it could squeeze closed the fingers of the sleeve enough to hold the stem inward, in winding mode.

It looked like it worked, but it didn't work...

I think the tips of the sleeve fingers, which bent inward to grip the stem are also worn.

I'm lucky this part is not actually broken. I can not replace it. In fact I've never seen one like this on anything but the smallest watches.

I decided to try a bell-hollow tip stack and flat stump in the stacking set.

This worked better. It barely, barely holds. I can tell it won't last. But it maybe the best it can be.

Meanwhile, job number 180068 is a Waltham in for service and a (hopefully) minor repair.

Rate and Accuracy in Vintage Watches

I often go to a fair amount of effort to get even what were originally inexpensive antique watches to keep time well. I think I may stop doing this, or at least not as much. And this post is about the reasons... But before going further a few points about mechanical watches in general, and vintage mechanical watches in particular, are in order. A few points about mechanical watches...

Hands

The hands on a mechanical watch are geared together. They can not, if everything is functioning correctly, move independently. Their movement relative to each other is mechanically dictated by gear ratios. For example, the minute hand must advance one minute each time the seconds hand completes one trip around. Likewise the hour hand must advance one minute each time then minute hand completes one trip around the dial. It can not be otherwise as the hands are mechanically joined by gears.

Rate

We expect the minute hand to complete one trip around the dial in one minute, as read by some external reference. However, the hands actually do not move in a smooth motion. All the hands jump forward several times a second. Between these jumps, all the hands are still. How many of these jumps occur in one obsolete, correct minute is what dictates how well the watch reads time. How fast the hands move, the speed of the tip of the hand, when the the hand is actually moving, is almost always irrelevant.

One can see these jumps in the movement of the seconds hand on a mechanical watch. The other hands are also jumping, all at the same instant.

Escapement

Mechanical timekeeping is possible because of an escapement. The escapement "escapes" power into the gear train many times a second. At each beat of the escapement, the gears turn. Then they go still again in between. The escapement controls the frequency of the hands advancing, and thus the accuracy of the watch over time.

What is time keeping?

The "accuracy" of a watch boils down to how fast the hands move around the dial according to some reference time source. But all mechanical watches (really, all, even new ones) have certain issues that impact this.

Mainsprings impart more power when first wound than when almost run down. So the rate of a watch wound in the morning varies as the day passes. Watches may have some means of compensating for this. Most older ones do not.

Gravity effects the hairspring. The hairspring and the balance wheel dictate the frequency of the escapement, and so alter the reading of time on the hands. A wristwatch is in many different orientations as it is worn, so the rate varies over the day, moment to moment. Again, some watches have the means to reduce this variation.

These are just two examples. There are more many factors that also alter the watch escapement from moment to moment under normal operating conditions, on a watch that is functioning correctly. Because these issues exist, watchmakers of old did not even bother to measure a watches rate moment to moment. They were only interested in a watch that read good time after running for some period without being reset (a day, or several days). Sometimes during the run interval the rate may gain, and sometimes lose. Watch "adjustment" is setting up everything so that plus and minus errors (the ones we can do nothing about) cancel each other out over time.

Age

In vintage watches there is another factor; simply the passage of time. Old style, steel hairsprings change their metallurgic properties with the passage of decades. Simply put, a spring just isn't as springy anymore. As a result, the frequency of the escapement is impacted. The solution would be the installation of a newly manufactured spring. But this is not usually possible as they do not exist.

In these cases, there are several adjustments that can be made. One can adjust the mass of the balance wheel. The balance screws provide this mass. They can be replaced, in opposite pairs, with lighter or heavier screws.

This is time consuming work. Once the screws are disturbed, the rate will usually be way off, out of the ballpark. Pulling it back in takes a lot of basically trial and error.

The Regulator

All of the above applies to watches that have been correctly serviced and repaired and are functioning correctly. Watch designers selected mainspring strength, gears, hairspring strength and balance mass to result in a watch that would be in the ballpark of the correct time after the passage of an interval (say 24 hours). Was a watch, assembled at the factory, ready to go and accurate? No. Manufacturing was not that good. It was close though. So what did they consider "in the ballpark"?

We actually have a pretty good idea. Mechanical watches feature a regulator that can be adjusted by a watchmaker, or the end-user if they like, to effectively lengthen or shorten the installed hairspring, and thus alter the frequency of the beat, and thus the rate of the watch. On vintage pocketwatches, the range of the regulator is about +/- 5 minutes per 24 hours (this does vary from design to design, it can be as much as 10 minutes) over the end to end sweep of its setting.

So, we know that watch designers knew that between variation in manufacturing precision, and variation in real world conditions, an error of +/- 5 minutes was to be expected.

A Proposition...

Within the range of error provided for by the regulator, a fully serviced watch is functioning correctly.

The people that designed the watch did their job as well as they could, with the tools and technologies of their time, and within their business requirements. If they could be assured that each watch would leave the factory more accurate than they did, they would have reduced the range available on the regulator. Or perhaps left the regulator off altogether. In short, the range of the regulator represents the expected range of error in a perfectly working watch.

Antiques

All of the above points that impact the rate of a mechanical watch are general. I'd like to add one more that is specific to antiques; history.

Whether a watch was an economy 7 jewel model, or a high end 23 jewel watch that originally cost 15 times as much, after 100 years they are all individuals. It doesn't matter what sort of watch it is if it's been through two loads of laundry, a fire, and stored in a damp and dirty junk drawer in the garage with the oily rags for 30 years. Watches are not magical. They are constructed (mostly) of machined pieces of relatively soft metal. Countless damages can happen to these parts over the decades that can not be undone.

What's more, a 100 year old watch has likely been serviced and repaired dozens of times, with varying levels of appropriateness. It is extremely common to see parts in a watch that have been replaced with the best thing available at the time - an incorrect or handmade part, and the rest of the watch permanently altered to make an incorrect part work.

From time to time I get an objection from a watch owner that their once high-end railroad watch should keep better time because of what is was when it left the factory. In a few of these cases over the years, I confess I had to laugh (fortunately my communication with watch owners is almost never face to face) because the watch was in such horrendous condition that I was pretty pleased with myself for getting it to even tick. They would have been hard pressed to find another watchmaker that would have even taken on the challenge.

In short, it doesn't matter what the watch once was. It matters what has happened to it since it left the factory.

Adjustment

Now we come to the heart of the matter. Just how accurate should we make an antique watch? I'll  make several points about this.

1) It doesn't matter.
What's important is that an antique is in good condition, functioning correctly, rust-free, correctly lubricated, stored in a clean, dry manner, and preserved for future generations. Even setting aside family heirlooms, how well a watch keeps time (once it is functioning correctly), among serious collectors, is not even a secondary concern. A watch that keeps time to +/- 30 seconds a day is not automatically "better" that a different instance of the same watch that runs +/- 1 minute a day, In fact, the opposite may well be true as so many other factors are more important.

2) Diminishing returns for the effort
If someone wants to pay me for the 40 hours (or more) that it might take to bring a hypothetical watch from +/- 10 seconds a day to +/-  6 seconds a day, in multiple positions, reliably, let me know. They did that sort of thing at the factory, but on dozens of brand new, mint watches, all at the same time.

3) Why?
Why worry about time keeping at all? With basic effort, and service by appropriate procedures, many (no, not all) watches fall with a minute or two of error fresh off the bench before I even touch the regulator. How much time and effort should be devoted to fine tuning?

Well, before answering, keep in mind that the watch doesn't "care", at all. Once it it operating correctly, there is no difference at all, for the watch, if the error is two minutes or 10 seconds a day. So the only reasons to do adjustment, are for time keeping, or for fun. As for the former, if you want to know what time it is accurately, and that is important, get a cheap quartz watch or use your mobile phone. These are a 1000 times more accurate than any mechanical watch will ever be, new or old.

So how much effort? I try to strike a reasonable balance. Almost all get to less than 10 seconds a day of error in at least dial up position, and many less than +/- 5 seconds. I consider that excellent. These watches come from a time when it was not unusual for people to be walking around with watches that read +/- 10 minutes a day.

I spend more effort reducing the beat error than the rate though, since beat error is actually a fault causing inefficiency, regardless of the rate. But it does take quite a bit of time to work on the rate, especially if the balance has to be adjusted in anyway. I think perhaps time might be better spent getting more watches to run well, rather than seeing how good each one can possibly keep time.

What do you think?

More about watch accuracy here...

Job Number 170041

Here is a grade 252, 18 size, 21 jewels, made about 1901. 

Assembling one of these is not for the faint of heart. The pivots of the pallet and escape are very fine, all with cape jewels. Sleight pressure will snap them. Everything have to be lined up for the upper plate to go one.

After putting the upper plate in place, I noticed that one of the pallet stone was loose! Well, apart it come again to fix that. The stone are held with melted shellac, heated over an alchol flame with this warmer.

This plate screw has an unfinished head. It gets covered up by the balance cock when the movement is fully assembled.

Here is the fancier plate screw, polished and chamfered.

The pivots on the replacement staff are just a little too large. I took them down a little to get the balance wheel to move completely free.

The old broken staff is removed using the lathe to cut away the hub, opposite the riveted side. Normally, this is cut away to almost nothing, then popped off with he staking set, leaving the old staff and a tiny washer that is all that's left of the hub. With a real sharp graver though, on larger watches like this, I sometimes free the balance completely with the lathe. It takes just the right touch to do this without scraping the balance arms, but it can be done.

I went to put the balance on and saw that one of the regulator pins is missing! More to do...

The roller table is then reseated. This one is missing the roller jewel. I'll replace that next.

This is the tool used to hold a balance assembly, hairspring removed, and heat the roller table, melting shellac, to hold a roller jewel.

I got lucky this time and got the new roller jewel positioned just right on the first try. I usually have to reheat the shellac and straighten the jewel a couple of times.

See the complete album for this project here.

See more examples of Elgin Father Time watches here.

Find more horological content here.

Here is a pretty clear image of the ruby-red roller jewel (also called an impulse jewel or pin) on the roller table, on the completed balance assembly.

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!

Stem Dies and Crown Taps

From The American Horologist magazine, June, 1945

Stem Dies and Crown Taps
By Ronald L. Ives

Some years before the present war started, crown taps and "Swiss" screw plates became scarce, and (with some exceptions). of poor quality. Since the war began, these items are practicaly unobtainable. Crowns still need tapping, and probably more new stems are being made today than ever before.
Published screw tables indicate that the following stem tap sizes are "standard":

Diameter, Inches     Threads per inch
.091                         60
.077                         72
.061                         80
.048                         110

These sizes, unfortunately, are only approximate, and do not take into account the plague of "bastard" threads used on "gyp" watches.

Search for suitable threading tools that are obtainable shows that there is no good substitute for the .048/110 tap and plate thread.

A standard machinist's tap of 0-80 size has a nominal diameter of .0600 inches, with 80 threads to the inch. An 0-80 bottoming tap can be used in place of a .061 crown tap with about 95 percent success. 

The 0-80 die can be used to thread a stem for this tap, or if a round split die, such as a Greenfield type 382 is used, it can be opened sightly, by use of the adjusting screw, so that threads cut with it will make a fit of any tightness desired in a pretapped crown.

If the thread is started with the front portion of the die, which is relieved, and finished with the rear portion (by reversing the die in the holder) a very clean thread can be cut. 

For the .077/72 crown tap a 1-72 machinist's tap can be used, this tap having a nominal diameter of .0730 inches. This substitution will work 9.bout 80 percent of the time without further work. The 1-72 round split die can be used as suggested for the 0-80.

There is no standard machinist's die having a 60 thread count. Both the 2-56 and the 2-64 tap have a diameter close to .0860 inches, which is .005" smaller than the .091 nominal diameter of the 60 TPI crown tap. Both of these sizes will work satisfactorily in stem and crown assemblies, although the 2-64 size, with its greater root diameter, is probably to be preferred. Both of these sizes, it should. be realized, even though they are standard in machine and instrument practice, are "bastards" so far as the average watchmaker is concerned, and their use, even though mechanically sound and justifiable, should be reserved for emergencies. 

Elgin Watchmakers College Student Work

This is a brass plate with five different types of jewel settings used in train jeweling, in vintage watches. This was made at the Elgin Watchmakers Collage to show competency with the various jeweling techniques. All the parts, other than the jewels themselves are hand made from scratch as part of the project.

My grandfather made this during his time at the school in the 1930s.

The Making Of A Balance Staff

From The American Horologist magazine, June, 1945

The Making Of A Balance Staff
By Emanuel Seibel

In making a Balance Staff we must know how to get the measurements in case no sample is available and never take it for granted that the one in the watch is correct. Which is a very good rule to follow in anything to be replaced in a movement, especially Mainsprings. The greater majority of the men at the bench do not know how to go about selecting correct material, muchless know how to measure a movement for a correct Staff.

We will now consider a relatively simple way of getting at the correct measurement for a Staff for a particular movement.

In our illustration, we show the essential parts in getting these measurements. We have taken a type that is used in practically everything from 16s down. For 18s the system of measuring is exactly the same except you use the top plate in place of the pallet bridge in our illustration.

1. is the lower or main plate 2. is the balance cock 3. is the pallet bridge Now, the first essential is to know the overall (a) length that your staff must be.

This is gotten by removing both cap jewels and being positive that both hole jewels are positively seated in the bottoms of their respective sinks. Use a slide or a spring millimeter gauge and measure the distance from the face of one balance joint to the face of the other jewel.

This is the direct method. You can accomplish the same by measuring over the cap jewels on either and deducting the thickness of both cap jewels from the first measurement.

Next, we must find the correct distance from the end of the upper pivot to the seat for the balance or the top of the hub (b). For this we will use the slide gauge and get the distance from the top of the balance cock to the top of the pallet bridge, and subtract the thickness of the upper cap jewel; but this would let the balance rest on the pallet bridge, so we must deduct .01 or .02 mm from this last figure so as to give balance wheel the proper clearance over the pallet bridge (e).

We still have 2 more preliminary measurements to find before we can begin to cut our staff for we only know how long the upper ball (b) of the staff is and the overall (a).

We must now find the height of the hub so as to get clearance between the under side of the roller table and the top of the pallet fork. We can get this by measuring with the slide gauge from the top of the pallet bridge to the top of the pallet fork.

From this measurement, deduct clearance between roller and fork and add the clearance allowed between balance and pallet bridge (e).

This is the total measurement of hub and roller. Then deduct the thickness of the roller and the result is the height of the hub (d). The remainder of the overall length is the roller shoulder and the lower pivot (c). 

In the ordinary 16 and 12 size movement, we can allow a slight variation in the height of the hub, but in thin models and ultra thin movements, the dimensions must be exact and no mistake about it.
Now, as to the length of the hairspring shoulder, it should be as high as the hairspring collet and its diameter should be about .01 larger than the inside diameter of the hole through the collet. This can be gotten by slipping the collet on a burnishing broach and gauging the broach directly under the collet against the broach. The collet must spread almost imperceptibly in going onto its shoulder. Of course, the balance shoulder is made to fit opening in the balance arm without any side shake and just about .01 or .02 mm at the most higher than the thickness of balance arm.

The pivots. in any watch should be the same size but especially in a fine movement. They should not be any longer than necessary to reach through the hole jewel and touch cap jewel without binding or riding on the cone in the edge of the hole.

Pivots should be as large as the jewels will stand and still allow positive freedom. The endshake should be just sufficient to guarantee positive freedom. 

To Prevent Oil From Creeping

From The American Horologist magazine, July, 1944

To Prevent Oil From Creeping

For clocks, meters, and other work which it is not desirable to immerse in the solution, it is sufficient to apply to the pivots, bearings, holes and other rubbing surfaces a pegwood nib or pencil brush dipped in the Epilame solution and allow the parts to dry before assembling. Remove, if necessary, any residue after evaporation, as described for watches.

In spite of its infinitesimal thickness, the Epilame deposit which covers the surfaces offers considerable resistance, and only a severe scratch or passing the parts through benzine would remove the coating, in which case it would be necessary to prepare the parts afresh in the bath after cleaning and before reoilng.

If after prolonged use the bath becomes cloudy owing to the presence of foreign matter deposited by the parts which have been immersed, all that is necessary is to pass the liquid through filter paper to restore it to its original condition.

The Separation of Static and Dynamic Beat

From The American Horologist magazine, July, 1944

The Separation of Static and Dynamic Beat
By Emanuel Seibel

To begin with, we are speaking of a good grade of watch in good mechanical condition.

What is good mechanical condition, you may ask.

First, it must be clean. Then we must have positive train freedom, but this freedom must be correct, not because pivots are sloppy but endshakes and sideshakes must be correct; these pivots must be well polished. Wheels must be absolutely round. Barrel arbor must fit as snugly as possible without bind. Center wheel must be upright; all wheel teeth straight without burs; pinions polished so that all frictions are reduced to a minimum.

Then your escapement must be set up as light as possible with safety.

Drops equal, lock and slide as light as you can make it, draw positive.

Roller jewel properly fit to fork slot and your guard sure, and the closer you can make pallet and balance shakes alike, the better you are off.

Now we are ready for poise. Most watchmakers poise to a square that is four points,-some to eight points or a double square. First, the balance must be absolutely true, round and flat. Before we attempt for poise, if the watch has the original staff in it, it should not require much, if any, poising; if a staff is being replaced, and old staff is turned out of wheel and properly staked fast, it should not need any, or very little, but poised it must be.

When you are satisfied it is as close to poised as it can be ,gotten, you have your static poise, or poise in rest.

Now, you put on your hairspring and your static poise is disturbed because your collet, to begin with, is not poised in itself and cannot be, for it has a slot in it, and if it is not a proper fit to Hairspring shoulder and is forced on staff, it is spread and the condition is aggravated. 

The spring, which is spiral, cannot be poised. Remember, the wheel itself is in poise at rest, but the complete assembly of wheel and spring has disturbed this static poise and we must get this assembly in dynamic poise (that is, in poise under power, or in motion). This is where the Watchmaster comes in.

Now, remember, the Watchmaster will not do it, and cannot do it. It can only indicate the trouble; and how you may correct it, is in your ability to interpret the readings of your Watchmaster and make the indicated adjustments.

Your balance under motion to function properly must have a turn and a quarter of vibration and we find that unless the hairspring is properly centered, positively true in round and flat and the pinning point correct so that it developes correctly, and breathes as it were, equally in all directions, you have unequal pushes and pulls in the spring, which disturb the rate and beat of your watch.

Just because your fork and roller are absolutely in line and in the absolute middle of the bankings, does not indicate that it is in beat, for the relationship of your pallets and roller may look correct in static condition, but when power is applied, your balance may pull to one side or the other and not start, and until you get this relationship of pallets to roller correct, it will not pull equally to either side and start. When this is correct, a watch in good mechanical condition will start off at the first twist of the crown. 

After a balance has been poised on a poising tool, equally weighted at every degree of the circle, balancing perfectly in all positions around the axis that balance is in "Static Poise" or in a state of equilibrium. (See Page No.6 in the Book. "12 Thousand Hours").

Counter poise, in the "Static Sphere" means you actually take off or add weight.

The average watchmaker will use four corners, or one square when poising a balance. The more critical workman will use eight corners or two squares. (See Drawing at Top).

It is true that often in poising a balance you start with the screws that are too far in to the center, and when you do this the balance will be under-compensated; naturally if you start with the screws that are too far away from center the balance will then be over-compensated. You must have compensation in "Static poise" or balance that will match as near as possible, the ability of hairspring in "Dynamic Poise", after you have this combination you never destroy static poise by moving or changing screws. 

After hairspring and collet have been added, and placed in watch, we then have the "Moving Element", when this, takes motion we are then concerned with "Dynamic poise".
(See Page No. 6 in the Book. "12 Thousand Hours").

Counter poise, in the "Dynamic Sphere" means, control of equilibrium in motion, and the control of this force is attained by changing the level of hairspring and push and pull under dynamic power. (See Page No.7 in the Book. "12 Thousand Hours").

Take a look at simple drawing at top. First we use the "Static Poise" and accept it as being correct. Then we check the watch on the Watchmaster. In motion we see the rate is good in all positions except P. R. & P. 1. Records show P. R. 5 Sec. slow and P. L. 5 Sec. fast. We instantly know that the "Push & Pull" of hairspring are not equal at these positions, where the "Push" develops towards the rim more than the "Pull", at that position the watch will run slow. Naturally at opposite position the watch will run fast. You simply cause the hairspring to have same ability in both positions. You do this with "Dynamic" counter-poise and NOT by changing screws and distorting your already correct 'static' counterpoise. 

Information Please!

From The American Horologist magazine, July, 1944

Information Please
Directed by 
W. H. Samelius, Chairman 
Science of Horology and Technical Advisory Board

HRG: I have an Illinois 60 hour Bunn Special watch. Please advise if this watch should be wound every 24 or 48 hours?

Ans.- In all watches the maianspring power delivered varies throughout the running period of the watch. By designing the watch to run 60 hours, the variation of power during the first 24 hour period is less than the variation of power during the latter 24 hours so for that reason, as the mainspring delivers more constant power for the first 24 hour period, it is advisable to wind the watch each 24 hours. If you accidentally omit winding the watch after the first 24 hours, it naturally will keep running until the end of its running time, but the time piece is very likely to take a different rate during the latter part of the run, therefore, we repeat, to obtain a constant rate, it is best to wind your watch each 24 

JIT: When a watch is marked adjusted to heat and cold, 5 positions and isochronism, what is meant by isochronism?

Ans.- The word "isochronism" is derived from the Greek word meaning "equal time." As applied to a watch or timekeeping instrument, the term "Isochronism" means that the time or rate would be constant throughout the 24 hour period, that is, it will have a constant gain or a constant loss for each hour of the day. Theoretically, a balance and hairspring should oscillate at the same rate whether the arc of motion is low or high, meaning that the balance should return to center in the same length of time, regardless if the arcs are unequal during the 24 hours due to the variation of power. The resistance of the hairspring must be equal to the force of the balance. As all hairsprings are not isochronal; it is some. times necessary to test several hairsprings before one is found that will prove itself isochronal throughout the range of balance arc. The length of the hairspring has a great deal to do when striving for isochronism.

HMU: A friend informs me he always puts oil on a roller jewel? 'Is this good practice?

Answer - Oiling the roller jewel is bad practice as the oil soon turns black or will thicken or gather dust, which will soon have effects on the watch. If oiling the roller jewel was the proper thing to do, I am sure all watch factories would adopt that method, however, up to date, you will find all watches as delivered by the manufacturers, are left with the roller jewel dry.

YKG: When inserting teeth m clock wheels, is it advisable to use hard solder?

Answer - When inserting a tooth in a clock wheel, a dove tail slot is cut into the rim, a wedge filed to fit the slot and held fast by spreading or riveting the wedge to place. If hard solder· is used, the heat would take the hardness away from the teeth of the wheels when they would very likely bend over and cause trouble when the wheel is put into service. It is even advisable to avoid using soft solder when inserting teeth into clock wheels.

In the sixteenth and seventeenth centuries, an HOUR glass was standard equipment in the church, so the sermon wouldn't last too long. 

Damaged Mainspring

This is a mainspring damaged likely as a result of installation with plain old fingers instead of a proper mainspring winder. Deformed and unusable...

Why So Many Crowns Are Lost

From The American Horologist magazine, July, 1944

Why So Many Crowns Are Lost

Every watchmaker has had the disagreeable experience of finding out that the winding-crown of a watch unscrews very easily, and can therefore be lost, even in the case of new watches. The watchmaker who cares about giving satisfaction to his customers is then obliged to replace the crowns lost in this way. After having studied the different causes and the ways of avoiding this accident, I have come to the following conclusions: 

The first and most important defect that I have note very often, even on new watches, is the fact that the surface of the crown, once the thread of the screw has been cut, is much too thin. We know only too well that a wrist watch is subject to hard wear and that the crown, extending beyond the watch, often receives hard knocks. As a result, the crown is gradually unscrewed. Make the following test:

Fix a crown with a thin surface or side to a winding-stem and fasten the stem either to a watch or to a mandril. Then strike a few time, even very lightly with a small brush, for instance, and you will see for yourself how easy it is to free the crown. After that, it will become completely unscrewed in a very short time. It is evident that a thin surface will bend at the slightest shock, and it is just at this time that the thread of the screw of the crown will not adhere closely to the screw of the stem.

A second defect which has often been noticed, is that of an insufficiently long screw thread in the crown. Often the tube of the crown is long enough, but it has not been cut deeply enough. In some others, the tube is too short and therefore has not sufficient grip. A crown of this kind is illustrated in fig. 1. A third error consists in filing the end of the winding-stem to a point, as indicated in fig. 2 under (a) and (b). It is easy to understand that it is not possible to screw a crown on a stem prepared in this way. Fig. 3 shows a crown fixed to one of these stems, while fig. 4, on the other hand, shows how the winding-stem should be filed. In fig. 2 No. (c) it can be clearly seen that the end should be flat.

It is natural, on the other hand, that the screw-thread of the winding stem should be similar to that of the crown, for it is impossible to fix a crown to a winding-stem if the screw-thread be too thin.

Sometimes, a watchmaker will come across soldered crowns, which is inadmissable.

I have often been able to ascertain that the apparently simple work of fixing the crown to the winding stem often presents important stumbling blocks.

It is an error to maintain the winding stem in a mandril when fixing the crown. In proceeding in this way, it is impossible not to break the winding-stem, for, as shown clearly in illustration 5, the pressure of the tongs of the mandril is exercised only on the most delicate part of the winding-stem, that is the notch for the setting-lever. It is certainly aggravating, at the last minute, to break a stem which has just been finished with much care and attention. But even if the stem should not break, it is a mistake to use the mandril, for it often leaves rough ridges, which once the stem is in place, act as reamers on the plate. Shortly after, the stem begins to "dance," the setting lever is not supported as it should, and when the hands are set, the stem falls out. If this happens with watches of well-known trade marks it is all the more disagreeable because of the fact that it will never be possible to use a winding-stem to fix the crown properly again.

I would recommend the use of the Seitz pliers, which can be obtained from Messrs. Bergeon of Le LocIe. I have made three pliers, adapted to a point similar to that illustrated in fig. 6. The reader will easily see that this point allows the fixing of the superior part of the winding-stem, avoiding all risks of a breakage. A second advantage is the fact that this tool avoids all risks of causing marks of any kind on the stem, as indicated above. I have these pliers in Nos. 8, 10, 12, which is largely sufficient for nearly all the work to be done on wrist watches.

I have been able to note that errors of this kind are made not only by small watch repairers, but also in large factories, where careful attention is paid to the execution of their products, but where insufficient care is taken in mounting the crown.