Saturday, September 14, 2013

And Now For Something Completely Different...

Lately, I've become interested in some of Elgin's OTHER products.  In addition to over 56,000,000 watches, Elgin also made several kinds of interval timers.

These are like stopwatches - normally the hands are still; push the crown and the second hand starts; push it again and it stops; push yet again and the second hand returns to zero.  Elgin made them in two different types - a 60 second timer, like the one on the left; and a 10 second timer like the one on the right.  In the former, the second hand takes 60 seconds to go around the dial, whereas in the latter, it takes only 10 seconds.  More on that later.

Elgins Timers differ from a standard stop watch in that while the balance and train on a stop watch run only when timing, the balance and train on the Elgin Timers runs as long as the piece is wound, with the hands only engaged and running when the crown is pushed.

The movements appear at first glance to be ordinary 16s Elgin pocket watch movements.  The 60 second timer on the left is a 7-jewel movement, grade 469.  This one dates to 1919.  The 10 second timer on the right is a 15-jewel 582, from 1942.  The gilt plates and plain finish mark this as a WWII piece - the War Department wouldn't pay for frills, apparently, and I also understand that nickel, normally used to coat the plates as in the 469, was needed for the war effort.  You'll also see gilt plates in some of the wrist watches produced at that time.

It looks like the 10 second timer has no balance, but it's there!  The 10 second timer runs at 30 beats per second, 6 times the speed of a normal watch.  To accomplish this, Elgin combined a small, light balance wheel with a strong hairspring.

There it is, whizzing away underneath the regulator!  These 10 second timers are often called 'Jitterbugs', because of the sound they make - a rattling buzz, kind of like an insect.  Although some of the 15j 582s were 60 second timers, most seem to be the Jitterbugs.  Once you see one running, you know why they didn't make the Jitterbugs in 7-jewel - they run so fast that they'd burn through their bushings in no time!

Okay, so how do they work?

What Elgin did was to add a column wheel chronograph-style stop works to the dial-side of a 16 size movement.

Compare this to the chronograph works on this Hamilton Model 23 chronograph.

Pushing the crown pushes down on the Actuating Lever at 1.  It pivots at 2, so that the distal end at 3 is pushed out, pulling the Cam Hook at 4 to the left.  The Cam Hook rotates the Column Wheel at 5 clockwise.  The column wheel is topped with 5 columns and 5 spaces. Three levers are worked by these columns and spaces, as you'll see.

When the crown is pushed once,the column wheel rotates so that the end of the Connecting Lever at 1 falls into a space, allowing it to pivot up.  This causes the Connecting Lever Pinion at 2 to move a tiny distance up.  The Connecting Lever Pinion is meshed with the 4th wheel on the train side so it rotates whenever the train is running.  The upper end moves into engagement with the Seconds Wheel, turning it at the same rate as the 4th wheel.

At the same time, the Flyback Lever at 3 engages a column, pushing it up so that the Minute and Second Flyback Hammers at 4 are lifted off the Heart Cams on the Second and Minute Wheels., allowing these wheels to turn.

The minute register does not turn smoothly, but rather jumps one space as the second hand passes Zero.  The Second Wheel has a Finger Piece at 1 which turns the intermediate wheel at 2 as it passes, once per rotation.  The Intermediate Wheel meshes with the Minute Register Wheel, so it turns it one click, limited by the Pawl Spring at 4.

A second push of the crown rotates the Column Wheel another step, causing a column to push the Connecting Lever down at 2, disengaging the Connecting Lever Pinion at 2 from the Second Wheel, stopping the hands.
A third push of the crown turns the Column Wheel so that the Flyback Lever at 1 falls into a space, causing the Flyback Hammers at 2 to hit the Heart Cams, swinging them to their lowest points, bringing the hands back to zero.

These timers were made in large numbers during WWII, and used for a variety of purposes.  Mostly, they're cased in one of the two styles I have shown here.  The Jitterbugs seem to have been cased only in the case shown here, while I've seen the 60 second timer in both styles, and with a number of different dials.  

Sunday, June 23, 2013

For A Few Dollars More - Part 5: Regulation and Casing

With your movement fully wound, and the regulator centered on the scale, you can regulate it.  That is, you can set the rate so that the watch will neither gain nor lose time.

 At the same time, you can determine amplitude and beat error.

Amplitude is how far the balance swings on each oscillation, and is a good measure of the condition of the watch, how good a job you've done cleaning it, and whether that mainspring really should have been replaced.  Ideally, amplitude should be greater than 250 degrees.  That is, the balance should swing at least 250 degrees past the point where the roller jewel is in line between the centerlines of the balance and pallet.

Beat error is a measure of how close to perfectly centered the roller jewel is when at rest.  Ideally, with no power in the train, the roller jewel should be exactly aligned between the balance and pallet, and should hold the pallet lever exactly midway between the banking pins.  This enhances accuracy, and allows the watch to 'self-start' with only a slight winding.  In a later post I'll cover how I determine beat error and minimize it. 

Although there are a number of timing machines available, if you've been following this blog you know by now that I'm cheap!  And in this case I'm also lucky!  If you look on watchmaking forums, you'll find a number of posts on using your PC to regulate your watches, and discussions of available software.  Invariably one reads about the necessity to obtain a proper piezoelectric microphone, and a preamplifier to boost the signal enough for the PC.  In my case, it turns out that the microphone built into the monitor frame of my laptop is perfect for picking up watch ticking!

That's the 642 sitting at the top of the monitor frame, next to the webcam.

I do have to lay it on it's back to do this, but it saves me buying a mic!  In this picture, you can also see one of the tools I use, biburo.  It used to be available for free download, but now the link is dead.


Biburo claims to be able to detect rate, beat error, and amplitude, though in practice it is best used just for rate.  I generally ignore the numbers Biburo gives me in any case, and just go by the trace.  In a watch that's running at the correct rate, the trace will be a straight horizonal line.  The deviation from horizontal indicates the error.  If the line tilts down, the watch is running slow.  If up, fast.

Here's the initial trace that this 642 produced:

Slow.  REALLY slow.  About 3 minutes slow/day.  Time to adjust it.  I like to use a piece of pegwood to move the regulator.  You COULD use tweezers, but they're likely to scratch the balance cock.

Watch the hairspring carefully as you do this.  Generally the regulator pins just move along the spring, but sometimes the pins grip the spring too tightly, and it pulls or pushes on the spring itself.  You can end up bending the spring if you're not careful!  Ask me how I know....

Generally, you don't need to push it very far.  Certainly not THIS far!   Here's what happened to the rate when I pushed the regulator all the way to the 'Fast' end of the scale:

Now it's too fast!  After a few attempts, I got it to this:

Not perfect, but only a few seconds per day of gain.   I decided to stop there.

Another important point about the trace is that there's a single line, which indicates low beat error.  With significant error, there would be two distinct lines.

Next, to get a more detailed view of how the watch is running, I use eTimer Watch Escapement Analyzer software.  There's a freely downloadable software package, in addition to the entire package of the software and the microphone setup.  The freeware is limited, and cannot analyze in real time.  You need to record the ticking, save it as a .wav file, and analyse the file.  This precluded making adjustments on the fly, but it's MUCH cheaper!!

To record the ticking I use Audacity,  a free audio editing software package. I record for about a minute, after adjusting the position of the watch for the best pickup.  This produces a trace like this:

If you look closely, you'll see a line of regularly-spaced spikes.  There should be 5 every second.

I export the trace as a .wav file.  Then I open it in eTimer, and allow the software to run.  In this case, it's run for 5 minutes, repeating the same 1 minute recording.

eTimer shows two ticks per screen, at the rate they occurred in the recording.  There are two ticks for each complete back-and-forth swing of the balance, and if the watch is running reasonably well each new tick will replace an old one, and you won't see the waveform trace wandering too much..

Each tick is composed of 3 components.  The first sound is the unlock, when the roller jewel hits the pallet fork, lifting it off the banking pin and unlocking the escape wheel.  The last sound is the lock, when the pallet lever hits the other banking pin and the escape wheel locks on the other pallet stone.

The pink strip emulates the paper on a Tick-O-Print, or similar watch timing machine.  There's a dot for each tick, and if the ticks occur perfectly at 1/5 second intervals, it will produce a straight line down the page.

The circle with lines emulates the Tick-O-Print cursor disk, and is how eTimer determines the rate, by aligning the cursor with the printed line of ticks.  In this case, about +6 seconds per day.  Ideally, the line would be straight, rather than wandering.  The wander suggests an issue with a part that turns with a period of about a minute, so there may be a small issue with the 4th wheel.

It determines amplitude by measuring the time between the unlock and the lock for each tick.  This interval is determined by the angular velocity of the balance as it swings through locking and unlocking.  The angular velocity at this point allows the calculation of the amplitude - here about 287 degrees - not bad for a 62 year old, 15 jewel watch!

It determines beat error based on the difference in the interval for alternate ticks - every other tick is a balance swing in the same direction.  Here the beat error is about 1.6 milliseconds.  Ideally, it would be under 0.5 ms, but that's for another post!

I declare this Good Enough!  Watches should be allowed to run for at least a day to settle in, distribute oil, etc. before final timing.

Time to finish putting the watch together.  Place the hour wheel over the cannon pinion, and add a dial washer if necessary.  Dial washers keep the hour wheel teeth meshed with the minute wheel by gently pushing against the dial.  This is not usually a problem with flat dials, but can become severe with curved ones - simply turning the watch dial down may allow the hour wheel to drop out of engagement, and the hour hand will get out of synchronization with the minute hand.

Then drop the dial onto the movement, making sure the dial feet enter the holes.  You may need to back the screws out just a bit.  When the dial is fully down, tighten the dial foot screws.

 Next install the second hand, making sure the pipe goes over the 4th wheel post, and pushing straight down, gently.

Now install the hour hand.  It fits onto the tube of the hour wheel.  To press it on, I use a flat-faced hollow punch from my staking set, with the hole just large enough to go over the cannon pinion but not the hour wheel tube.  This will put the hour hand at the top of the tube, so it doesn't drag on the dial, or catch on the second hand.

Set the hour hand EXACTLY to an hour mark.  I prefer to use 3:00 or 9:00, since that gets the hour hand out of the way of the minute hand, and by being at exactly 90 degrees from vertical, is easy to set accurately.

Place the minute hand on the cannon pinion, pointing exactly at 12:00, and press home with the stake.  You should feel a slight snap as the hand fits onto the tip of the cannon pinion.

Now you can set the time!  Mind you, that will turn out to be a waste....

Why?  The next step, at least for this watch, is to remove the stem, and the best way to do this so that you can later re-install it with ease is to pull the crown out to setting position.  Then, unscrew the setting lever screw just until the stem comes free.

With the stem removed, carefully lower the movement into place in the case.

This watch has a solid spacer ring, with a tab that fits into a notch on the bezel.  You can see them in this picture, at about 2:30, or 45 degrees counterclockwise from the hole for the stem.

Align the ring, and push down till it fits evenly around the movement.

Insert the stem.  You may have to wiggle it a bit to align the movement with the ring, and to properly engage the clutch, and get the setting lever engaged in the slot of the stem.  Tighten the setting lever screw till it stops, then pull out, push in, and tighten completely - just finger tight.

Now you can replace the back, making sure the threads engage properly before using much force to tighten it down.  Ideally, you'd have a gasket in this watch, but I don't have any.  Also ideally you'd use the proper wrench to tighten the caseback, but I don't have one of those, either!

And there you have it - a newly cleaned, lubricated, and regulated Elgin Shockmaster watch!  Ready for your wrist!

After the watch had been running for several days, I checked the rate again.  It was gaining a bit, so I adjusted it slower, using Biburo.  For a watch you wear every day, you'd observe how it ran on your wrist - does it gain or lose, and how much?  Then you could adjust it on the bench, using the timer, so that it should come out nearly perfect.  Although many collectors are satisfied with a watch that runs "plus or minus a few minutes a day", it's worth remembering that these were made to run within a few seconds a day. 

All together the whole process from arrival to recasing took about 4-5 hours.  A pro could do it faster, and a real novice should take longer.   Work at a speed you are comfortable with, and don't forget to take breaks for food and rest.  And whatever you do, DON'T try to do this when you're tired, hungry, anxious, or too excited!  Rested and relaxed is the key.

By the way, I also cleaned the case and polished the crystal.  I'll cover that sometime in the future.  Oh, and I added a new, and better-fitting bracelet.

For A Few Dollars More - Part 4: Reassembly

With the parts all cleaned, it's time to put it all back together into a working watch!

First, we need to oil and reassemble the balance jewels.  The shock-resistant jewels of the 642 are loose, so it's easy to put them together outside the movement.  I forgot to photograph the process with the 642's Incabloc jewels, so I put together a jewel set from a Kif shockproof setting.

Start by placing a drop of watch oil (I use Elgin M56b) in the center of the cap jewel.  Then place the hole jewel and setting on top of it.  The oil will then hold the two together, and if you were careful in putting them together, the oil will be nicely centered.

Next, replace the oiled jewels back in the shockproof settings in the balance cock and pillar plate.

Next, I wind the mainspring into the barrel.  Start by hooking the center coil onto the arbor of the winder.  Then wind it into the barrel.

Leave a little bit of the barrel end of the spring outside to allow you to orient it in the barrel.  Unwind the winder arbor, and then turn it backwards just a bit to disengage the mainspring.

 Elgin's 8/0 watches have a 'T' end, which fits into slots in the barrel floor and the cap.  Place the T end in the slot, lower the winder into the barrel and push on the plunger to insert the spring into the barrel.

With the spring in the barrel, add a few drops of heavy clock oil to the coils, insert the barrel arbor, CAREFULLY - again, the spring will try to throw it!  Turn the arbor to engage hook on the arbor with the hole in the end of the spring.

Next, put on the barrel cap, lining the slot up with the T-end of the mainspring.  Oil the barrel arbor where it exits the barrel, top and bottom.

Now we're ready to put it back together.  Lightly grease the sides of the setting lever screw and insert it, and place the barrel in its recess in the pillar plate.

Starting with the escape wheel, carefully place the train wheels in their jewels.

Install the barrel bridge, making sure you see the pivots of the center and 3rd wheels, and screw down.

Next, install the train bridge.  This is trickier.  Often the 4th wheel pivot will drop into place, but the escape wheel pivot will need to be worked around until it is in the hole.  At that point, the whole bridge often drops into place.  Before screwing it down, spin the center wheel and observe the other wheels of the train, especially the escape wheel.  It should spin smoothly for some time, slowing to a stop.  Screw the bridge down, checking the spin of the train again.

Oil the barrel arbor shoulders with two drops of Clock Oil, one on each side of the arbor.

At this point, I like to install the Crown and Ratchet wheels, and the click. Start by greasing the area where the crown wheel rubs - this will be obvious on any movement that got much use! Also rub a little grease on the click post.  On an 8/0 or 15/0 Elgin, you need to install the click spring before the ratchet wheel.  Be careful doing this because the spring will try to escape.  Hold the long end in a nice sturdy set of tweezers (I'm using #3s), and use either pegwood or another tweezer to push the 'shepherd's crook' end into the recesses.

Once it's in place, you can install the ratchet wheel.  Make sure the square hole engages the square post on the barrel arbor!

Screw down the ratchet wheel screw,add the click and screw it down, making sure the end of the click spring falls between the two teeth of the click.  Place the crown wheel, and grease the bearing surface where the crown wheel bushing rubs.  Place the bushing, then screw down the crown wheel screw - COUNTERCLOCKWISE!!!

Now it's time to oil the lower pivots, and install the keyless works on the dial side.  Oil the lower barrel arbor pivot with Clock Oil on the second smallest oiler.  Then, using the smallest oiler, touch the oiler into your watch oil, then touch the tip to the junction of the pivot and the jewel, so the oil goes only into the bearing surface, and not outside the oil cup.  In the loupe, you should be able to see the oil at the interface between the pivot and the jewel, but not in excess.

Finally, wipe some watch oil on the center wheel post to lubricate the cannon pinion, and install the cannon pinion.  Some folks wait till later to add the cannon pinion, but if you do it before installing the dial train and keyless works, you won't have to worry about aligning the teeth of the minute wheel with the cannon pinion and possibly crushing them.  This could cause the watch to stop at intervals.  The cannon pinion should snap onto the post with a light pressure.  If it just slides on with no resistance, it probably needs tightening.  If it takes too much pressure, you risk driving out the upper center wheel jewel if you push too hard!

Next, install the clutch lever spring, again taking care to hold it with tweezers while pushing the loop into place over the post with pegwood or another tweezer.

Now install the setting lever, after greasing it where it engages the slot in the stem, and where it rubs on the clutch lever.  Place it on the tip of the setting lever screw, then turn the screw until it has threaded and is pulling the setting lever down.

Grease the slot on the clutch lever, and the clutch teeth that engage the bevel pinion.

Now install the bevel pinion, clutch, and the dial train.  Elgin says NOT to lubricate the minute wheel or setting wheel.

Grease the clutch lever post on the minute wheel clamp, and the post on the setting lever that the minute wheel clamp spring engages.  Place the clutch lever on the post, then install the minute wheel clamp.

This step requires careful fiddling.  You need to get the clutch lever tip engaged in the slot on the clutch; the clutch lever spring out from under the clutch lever and pushing the clutch lever toward the setting lever, the tip of the setting lever engaged in the notch in the clutch lever, and the minute wheel clamp spring engaging the setting lever post.

Sorry, no pictures!  You'll have to figure it out!  Just work carefully, and when everything is in place, the minute wheel clamp will drop into place, and the clutch lever and the clutch will work up and down easily.  Add the two minute wheel screws and tighten them down.

 Inserting the stem can help keep the clutch in place while you place the clutch lever.  First, though, the stem must be greased on the tip where it enters the pillar plate, the flats where the clutch slides, and the bearing surfaces where the bevel pinion and setting lever tip engage the stem.  Tighten down the setting lever screw went the setting lever is in the slot.  Push and pull the crown several times, and turn the crown to test the setting and winding modes.

Now flip the watch over in the holder, and oil the upper pivots with Watch Oil.  Note that the oiler touches only the center of the jewel.

With the crown, wind it up just a few clicks.  The train should spin smoothly, come to a stop, then spin backwards for a bit.  The momentum of the smoothly-running train will carry it past fully unwinding, and this will cause the train to spin backwards to a stop.  This is called 'backlash'.

If you don't get backlash, I hate to say this, but you'll need to address this before proceeding.  It may even mean cleaning the whole thing again!

If the escape wheel teeth are not accessible when the watch is fully assembled, as on Elgin 8/0 movements, I oil 3-5 teeth of the escape wheel, on the impulse surfaces only, with Moebius 9415.

Now add the pallet.   Check to make sure the lower pivot is in the jewel by gently attempting to move it side to side.  Then place the pallet bridge.  Be very careful to ensure the upper pivot is in the jewel before screwing the bridge down.  This may take some fiddling - it always does for me!!  Ever so gently, manipulate the fork end of the pallet while applying GENTLE pressure to the bridge.  When the pivots are in place, the bridge unmistakeably drops into place.

Check for the glint of the pivot in the jewel hole before gently pushing the bridge down into place.  This way, the screw should encounter no resistance until it bottoms out in the hole.  Once this is done, check the pallet for freedom of motion, and wind the watch up just a bit.

Next, I turn the balance cock upside down and place it on my bench block, and lower the balance - roller side up - into place, with the pivot in the jewel and the stud in the hole.  I gently push the stud all the way down, assuming it hasn't dropped in already, and tighten the stud screw.

Holding the balance cock in the tweezers, I flip it over.  Check whether the hairspring falls between the regulator pins.  If not, you may have to re-do installing the balance in the cock, or sometimes it's just a matter of gently moving the hairspring over into place.  Remember it's fragile, and it is what determines how accurately your watch will run!

Now I lower it into the movement.  Getting the roller on the right side of the fork is tricky, and different folks have different approaches.  I like to flick the fork over to the inside banking pin, and bring the balance in with the cock rotated clockwise away from it.  This places the roller to the right of the fork.  Once the lower pivot is in place, I rotate the balance cock counterclockwise while lowering it into place.  The roller goes right in.

If you've done it right, and if the balance is anywhere near being in beat, it should start running.  Gently work the balance cock down into place, making sure the balance keeps turning.  This will ensure that the upper pivot is going into the hole jewel.  If it stops turning, stop pushing, and gently flick the wheel to start it again.  If it keeps turning, keep going.  If not, back up, and try again.  Generally, it's easier than it sounds here!

Once the balance cock is all the way down, with the balance still turning, insert the screw and slowly tighten it down.  The balance should be turning the whole time, and when you're finished, should keep turning.

Now that it's put together and running, slowly wind it up to full strength, and note how much amplitude you have.  It's hard to tell in actual degrees by eye, without experience, but after a few, you'll have a pretty good idea what constitutes good balance motion.

This is also a good time to observe whether the balance is running true in both the flat and the round.  That is, viewed from above, does the balance appear to wobble side to side; viewed from the side, does the rim appear to wobble up and down?

Observe the 'breathing' of the hairspring.  Does it expand and contract evenly?  Or is it pushed off to one side?  If that's the case, you may need to adjust it.  That is beyond the scope of this blog.  Before attempting to adjust a hairspring, you need to read up on it, in Fried's "Watch Repairer's Manual" or in the section on Hairsprings in the TM9-1575 Technical Manual, or in another book on watchmaking.  If you don't feel confident of your ability to do it without damaging the hairspring, just let down the power and put this one aside till you're ready.

Now that the movement is clean, lubed, and running, the next stage is regulation and casing.  That will be the next post!