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LONGINES CHARLES LINDBERGH HOUR ANGLE

STRIPDOWN & SERVICE

CAL L628.1 (ETA 2892-2)

First we need to have a look & see what we are up against. We have been informed that the movement has never been serviced. So let's have a look.

Timings a bit amiss, Amplitude very poor, Beat Error is well out of range.

A good service should rectify this.

First job to remove the Rotor Bridge, with Rotor attached, as it is held in place, underneath, with 3 tiny mounting screws.

Rotor Bridge removed, having undone 3 Blued Screws in to Bottom Plate.

Power in Mainspring now needs to be let down, via the Click Spring, located above the Barrel in the Barrel Bridge &

the Crown to control rate of tension release. After removal of the Train Bridge, we shall have access to the Train Wheels.

With Wheels removed, the Hack Lever is also removed.

The Lever allows the Balance to be stopped so the Second Hand can be accurately synchronised with the correct time, to the second.

This then enables the removal of the Balance Cock with Balance attached.

With the Barrel Bridge removed, this exposes the Barrel, Ratchet Wheel & Intermediate Wheel, which can then be removed.

As can be seen, a lot of detritus under the Intermediate Wheel.

With everything off the Top Plate, we can remove the Movement Ring and flip the movement over to reveal the Keyless Work. So named as the introduction of this mechanism, did away with the need for a key, on the old Pocket watches , as was needed prior to the now “Keyless Works”.

All parts, in 3 trays, they will now be put through a series of special wash & rinse baths, being agitated and then spun between each cycle. The fully cleaned parts will then be dried at 70 degrees to negate the chance of any drying marks.

NOW THE FUN BEGINS. SERVICING AND PUTTING THE WHOLE MOVEMENT TOGETHER AGAIN

First to be inspected and re-assembled is the Mainspring, into the Barrel, with a slight smear, around the Barrel Wall, with Moebius 8217, braking grease. Closely followed by the Barrel Arbor, all tucked away when the Barrel Cap is replaced.

Now we start to put the movement back together, meticulous care is taken to examine each part, for signs of wear or damage. Each part is correctly lubricated as specified in the technical service guide for the movement. First part is the Barrel & Barrel Bridge after being reassembled with the Ratchet Wheel & Winding Gears.

Now the Train wheels are put in place. Once the Train Bridge is in place, we can check for end shake and side shake of each wheel.

Flip the Movement over & Lubricate the Keyless works after a bath in Fixodrop, which helps hold the oil or grease in place, exactly where we want it.

We can now oil all the Jewels on the Bottom Plate. Prior to fitting Pallets, Pallet Cock & Balance complete with Cock.

Oil all Top Plate Jewels, fit Balance & oil Incabloc Cap Jewels. The Exit Pallet has a tiny amount of Moebius 9415 grease, a special grease specifically for the pallets. NO oil is used on the Pallet Lever pinions.

The Incabloc Cap Jewel needs to be oiled to approx 3/5ths of its surface area. It is extremely small & needs practice to achieve the desired amount of oil.

Cap Jewel in place

The Movement can now be wound, then an initial test on a Timegrapher to check Beat Error & if any adjustment is required to the Regulator to establish the correct rate of +/- seconds per day.

Happy with that, straight, “out of the bag”, so to speak. Amplitude is right where it needs to be on a movement of this quality. Only a few adjustments to alter the Beat Error and Secs/day.

A more in depth computer analysis will be carried out after a 24 hour settling in period, for the movement to bed down.

After a 24hr rest, all has worked out fine & no adjustment necessary. Pays to have a quick look at on the Timegrapher, so the Movement can settle to a near perfect state, so only minor adjustments may be required.

As all is satisfactory, fit the Motion Works, the Calendar Works.

Then the Movement Ring back on, test the operation of the Central Rotary Seconds sub-dial, all good then the, Dial & Hands can be replaced.

Once the Movement is back in the recently refurbished Case, the Automatic works can be replaced, once the Hack Lever is put into position, with the short leg engaging in the Clutch to operate the long leg, which interrupts the Balance to stop the Second Hand to allow perfect synchronisation of the time.