Durabalance Lord Elgins

In 1958, Elgin introduce the Durabalance.  This technologically advanced balance wheel incorporated several features.

The rim (A) was solid, rather than being drilled and tapped for balance screws.  Poising was done by removing weight under the rim

The balance arms (B), rather than being straight, spiraled out from the center, and were flexible.  This was to absorb shocks, so that movements of the heavy balance rim would not be transmitted to the fragile staff pivots.  Students of horology will realize that this idea was not new, but rather was lifted from the Wyler Incaflex

The hairspring was a flat spiral, rather than a Breguet overcoil, and was free sprung, meaning that there is no regulator, and the entire length of the spring from collet to stud is free to vibrate.  To regulate the rate, Elgin developed an ingenious system that made use of the spiral arms.  Rather than changing the free length of the hairspring to regulate the rate as in a standard watch, the Durabalance allows the user to change the moment of inertia of the balance, by moving two weights (D) in or out.  By moving the weights inward, the moment of inertia is decreased and the rate increased, and moving the weights out has the opposite effect.  The weights move along the spiral arms of the balance, and are coordinated by the use of a flat steel spring (C), which connects them.  Think of an ice skater doing a spin - the more tightly she holds her mass, the faster she spins.

It's a very elegant solution, in theory.  In practice, it's a little clunky.  To regulate the rate, you have to stop the balance and hold it still while you move the spring one way or the other, and despite those nice little marks on the rim in the picture, I've never seen a Durabalance that actually has the marks.  It's strictly trial and error.

The first two movements to carry the Durabalance were the 730 and 750, 23 jewel 13/0 Lord Elgins.  This watch, a Lord Elgin Fargo, carries a 730.

If you look at the balance cock, you'll see there's no regulator, just indicators of which way to move the spring to change the rate.  Also notice the banking plate above the balance.  The Durabalance was more flexible than the standard balance, and Elgin took several precautions to keep the wheel  from flexing too much. 

Note also the little spring holding down the balance cap jewel.  This is not a shock spring, but rather simply to retain the unset cap jewel.  Unlike a shock resistant jewel system, the hole jewel is fixed.  Elgin felt shock protection was unnecessary, and even offered a lifetime guarantee on the Durabalance.  Of course, Elgin went out of business 11 years later, so good luck collecting!

The 750 was a sweep seconds movement.

 Elgin re-engineered the sweep second drive, presumably based on difficulties with the double sweep second wheels on the 630/716/724.  The 750 uses a single sweep wheel and a floating sweep second pinion that rides in a floating jewel that keeps it separated from the tip of the center wheel arbor.  The spring both holds the pinion in place and provides the necessary drag to prevent the second hand from skipping.  This movement also has a different retaining spring for the cap jewel.  Elgin considered these two types of spring interchangeable.

In 1960 Elgin introduced the 760, a completely American made self-winding movement using the Durabalance.  I'll post in greater detail on the 760 at another time, but here's one to contemplate till then...

Sometime later (the Elgin Service Manual update from September 1962 is the first mention), Elgin introduced a number of new Durabalance Lord Elgins.  The 770 appears to be the replacement for the 730

 With the 770, Elgin eliminated the retaining spring for the balance cap jewels, returning to screwed down settings on the cock dome and pillar plate.  They also eliminated the banking plate, and the stamping of the grade information on the train bridge.  From then on, that information was etched on the mirror-polished ratchet wheel.

Just as the 770 replaced, the 730, so the 775 replaced the 750.  This watch is a retirement watch for a steel worker, so it's in a stainless steel case normally reserved for the B.W. Raymond Railroad Chronometer.

The next in the series, the 780, was normally reserved for the B.W. Raymond watches, but I got this one in a retirement watch.

Like the 730A in the early B.W. Raymond wrist watches, the 780 is a hacking movement.  There is a spring which rubs on the balance rim when the stem is pulled out to setting position.  The tip of the stem pushes it out of the way, and off the balance, when returned to winding position.  This allowed the watch to be set to the second.

The next watch, the 784, has so far eluded me. I saw on a few months ago on Ebay, but it went out of my range.  Fortunately, the collector who bought it posted it on Watch Talk Forums, and he was kind enough to let me use his pictures.  THANKS, DEVIN!!

Devin's watch is a Lord Elgin Futura, usually known as the 'Mystery Dial Watch', because in place of an hour hand, there is a disk with a marker frictioned onto the hour wheel.  This is also one of Elgin's 'Horizon Look' watches.

The 784 is in pretty much all respects the same as the 770, except for the shorter 4th wheel post (no second hand).

Now we come to the end of the line for US-built Lord Elgins, the 785.  This picture is of a watch with a 785 that I don't own, but rather shamelessly nicked off the Intertubes.  Like the 784, it lacks a second hand.

I do own a watch with a 785 movement, however. 

It's in a watch labeled 'Elgin' rather than 'Lord Elgin'.  I don't know if it's a Franken, or perhaps an artifact of later operations in Elgin IL before the closure of the factory - perhaps they were just using up movements that were already built? 

After 1964, Elgin made and sold some Lord Elgins, but they were all just Swiss movements cased over here.  No more American-made Lord Elgins.

What $10 Will Get You, Part 2 - The Teardown

The next step in the restoration is to disassemble the movement for cleaning.  This is also when I have a look at all the bits and see what may need replacing.

Step one is to remove the hands.  To prevent damaging the dial, I place a piece of plastic sheet with a V cut in it over the dial.

 

Then I use my handy old K&D Hand Remover to pull them off the cannon pinion and hour wheel.  Since it pulls up on both sides, it won't risk bending the center wheel post.

I leave the second hand in place, then loosen the dial foot screws, and lift the dial off.

 At this point, I tried cleaning the dial.  On the left, pre-cleaning.  On the right, after soaking for about 10 minutes in Hagerty's Jewelry Cleaner.  A LITTLE better.

 

It's cleaned the worst of the grime, but left much of the pitting.  The corrosion has gotten below the lacquer, and I'll have to decide whether to redial - and that's if International Dial even has the right dies for this.

Back to the movement.  Before doing anything else, I let down the mainspring.  I turn the crown just enough to get the click out of the ratchet wheel teeth, then use a piece of pegwood, or tweezer tips to hold it out of the teeth while i allow the crown to spin slowly backwards agains the pressure of my index finger.

After that, the next step is to remove the balance.  Start by loosening the hairspring stud screw and pushing the stud out of the hole in the balance cock.  Then unscrew the cock screw and lift the balance cock off.  Sometimes you need to use a screwdriver to pry the cock up just a bit.

Next lift out the balance.  Now's a good time to inspect it.

The balance on a 526 of this age was a split, bimetallic balance with a blue steel hairspring.  At first glance, the hairspring looks pretty good.  Concentric, and the overcoil looks fine.  If you look closely at the right hand picture, you can see that both pivots of the balance are present - No staff replacement needed!!

Next step is to remove the two screws holding the cock dome (upper cap jewel setting) and take off the dome and the regulator.

 It's hard to see here, but there's the usual dried oil on the cap jewel - that's why we clean 'em!

Next, unscrew the pallet bridge screw and remove the bridge and the pallet.

Nothing apparently wrong with the pallet.  I check the impulse faces by holding them in tweezers and turning them till they catch the light.  Then it's easy to see any chips.

Now that the pallet is gone, you can check the freedom of the train.  I wind it a few clicks of the ratchet wheel and watch.  

Generally, unless there's a REALLY BAD problem, the train will spin.  In a dirty watch, it spin forwards and jerk to a stop.  In a clean watch, the train will spin freely, then the momentum will carry it past complete unwinding, and it will stop and spin backwards for a bit before gently coming to rest.

Next step is to remove the keyless works and dial train.

 The minute wheel clamp screws on these early 8/0s are WAY longer than they need to be!  But remove them, and the minute wheel clamp comes off, along with the clutch lever.  Now I remove the minute wheel and setting wheel, and the clutch lever spring.  Turning the movement over, I loosen the set lever screw until the set lever falls off, then pull the stem and remove the bevel pinion and clutch.

Now to remove the train.  First I remove the ratchet wheel, click, and crown wheel.  REMEMBER - the crown wheel screw is LEFT HAND THREAD!  It turns CLOCKWISE to loosen!

Here you can see the click spring.  CAREFULLY remove it - they ain't makin' any more of them!

Now remove the train bridge, and then the barrel bridge.

 Remove the train, the barrel, and the set lever screw, and you're left with just the pillar plate (I removed the lower balance cap jewel screws and setting earlier.

The last step is to pop the cap off the barrel and have a look at the mainspring.  In this case, it's a blue steel spring that's completely set.  Fortunately, I have 8/0 alloy mainsprings to replace it.

 

And that's it!  Now the watch is completely disassembled, ready for cleaning. 

What $10 Will Get You

I wanted to do a post on the start-to-finish process of restoring a watch - well, MY process anyway! 

I picked up a watch on Ebay the other day, for $10.01.  I guesstimated it to date from the late 1930s, based on the shape.  I've recently been building my collection at the early end of the 1935-1964 period, having acquired a watch with a 21j 531 and another with a 15j 519, and I figured this watch would fall into that range.

  Here's the seller's photo.

When I bid, I didn't know whether it would be a 15/0 or an 8/0.  It might even have been earlier, which would put it out of my range.  But for $10, it was worth a shot.

Last night it arrived.  It is in grubby condition, with a worn out band attached with grungy green spring bars; a cracked, yellowed plastic crystal that came apart when i tried to remove it; a dirty dial that may be worse than dirty - pitted maybe?

Ah, but inside, there's a 7j 526 from 1936.  This is an 8/0 movement made from 1936-1938, presumably the very bottom of Elgin's line.  The case is 10k Gold filled, with brassing on the high points, but lacking the wear-through and holing that one sometimes sees.

This is a nice pickup!  I didn't have a 526, and this one has a balance in good condition, so likely it just needs cleaning and a new mainspring.  I'll get to that when I next update this post...

Bumper!

In about 1950, Elgin released what is generally acknowledged as the first American-designed and -built automatic wrist watches, carrying the 18j, 5/0 sized 607 movement.  These watches are called 'Bumper Automatics', because rather than a rotor, they are wound by the motion of an oscillating weight that swings between two buffer springs.

Here's mine, and a 1951 Elgin ad with the same model.

 I love that - 'Fresh, clean-cut masculine look'!

I was lucky enough to get one in excellent condition, so I have not even tried to remove the caseback.  I really wanted to see what made it tick, though.

A month or so ago, an uncased 607 movement came up on Ebay.  I bid and won it!  This, I decided, would be my victim!

 Under the dial, it's just like any Elgin of the era.  Nothing particularly special from this angle....

Viewed from the back, the 'Bumper' moniker becomes more obvious.

You can see the oscillating weight at the top of the picture, and at the bottom, the two buffer springs.  The weight has roughly 160 degrees of travel, from buffer to buffer.  When you're wearing it, you sometimes feel a very light 'thunk' when the weight hits the buffers.

The first step is to remove the winding assembly.  Undo the two screws, and off it comes.

 Here's how it works:

The pinion in the middle of the autowind bridge engages the crown wheel, so that turning it turns the crown wheel, which turns the ratchet wheel, and winds the watch.

Here's the assembly...disassembled.

The rest of the movement is pretty standard.  

The sweep second hand is driven directly, meaning that the 4th wheel runs concentrically with the center wheel.  It has a long post that runs down through the hollow center wheel arbor.

 Because of this, the movement is quite thick, even without the autowind works.  Look at the length of the set lever screw on the left hand edge of the movement.

The rest of the disassembly is just the same as any other watch.  Here it is in pieces, waiting for me to clean and reassemble it.

I'll update the post when I get to it!