The movement is placed in a movement holder, and the necessary tools to disassemble the movement are made ready.
First is the balance wheel. Here you can see the bridge, with the very minimalist use of a diamond balance jewel end cap.
This photo records the position of the hairspring stud, as this is important when replacing the balance staff. The position of the stud influences the swing of the balance.
A view of the bridge, which holds the hairspring stud by a single screw.
Underside of the balance wheel, showing the position of the roller table and impulse jewel- this is characteristic of English watchmaking.
The distinct sickle or crescent shaped escapement bridge is now clearly visible.
The bridge holds the club-ended escape lever and the escape wheel.
All bridges have a slight notch to aid in their removal.
A surprise! The previous watchmaker added a fine paper shim to the bottom of the bridge. This effects the position of the jewels against the pivots and thus, the timing of the movement.
The underside of the escapement bridge. With the last two digits of the serial number stamped.
A view of the movement without the escapement bridge.
Now to remove some of the keyless works. Here a view of the London/Liverpool rocking lever (more ahead on this).
The cannon pinion removed, here the bottom part shows the recessed area. This is to prevent lateral movement of the pinion, and a facet of English watches. Also the three part center wheel (center wheel, through-pinion, and cannon pinion).
A look at the mainspring ratchet wheel, which has a holding pin to secure the wheel onto the mainspring arbor.
This pin needs to be removed to extract the mainspring. This is a classic English method of securing the ratchet wheel.
Detail of the brass splinter.
Brass splinter removed, a new one will be made and substituted.
With the center wheel pinion extracted and the mainspring ratchet wheel, the back 3/4 plate can be removed.
The 3/4 plate, with it's beautiful curved lines. The large brass bushing is not decoration, but a reinforcement of the plate, since it is quite thin.
The underside of the 3/4 plate, showing the recessed area for the mainspring barrel, and hence the need to reinforce the area with a brass bushing.
Detail of the hand stamped serial number.
In the center wheel hole, there is a piece of lint, showing that this movement has been off it's case for some time.
Upon disassembly, the third wheel pivot shows that it is broken.
It is a clean brake, these types of breaks are usually related to rusting of the pivots.
In fact, the pivot is still in the jewel, and it is very dark - revealing in fact signs of rust.
Taking the rest of the gear train off.
The main plate of the movement, with the top rocking lever spring still in place.
The 6 armed wheel. Traditional high-grade English watches used 6 arms on their gear train.
Here, below, you can see for comparison a Swiss wheel, with it's characteristic 5-arms. The 6 armed wheel gives a different visual sense of weight to the wheels.
The balance wheel end jewel-cap has been replaced, as well as the top holding screw. This will be remediated.
The center wheel components, center wheel pinion, and cannon pinion.
A look at the balance wheel pivots, the bottom pivot is slightly bent and rusted. This will need to be fixed.
A view of the top of the main plate with the keyless works removed (the 1/3 gear-train bridge will be removed next).
A look at the keyless works: here you see the components of the London/Liverpool styled rocking lever, with the lever itself resting underneath the gears. Making it visually very pleasing.
The left hand side is the talon mainspring click, which is of a typical London made shape.
The rocking lever spring, is under the mainplate, as it pushes on a pin that protrudes down and into the movement.
The 1/3 gear-train plate screws, with rounded edges, so that their tips don't interfere with the gear train.
In comparison, here are the 3/4 plate screws, with their characteristically pointed ends, which screw into the pillars holding the 3/4 plate above the main-plate.
The bottom of the 1/3 gear-train plate, along with its screws.
Here you can see also the recess for the 3rd wheel, the recess coincides with the circumference of the 3rd wheel which intersects with the center of the 4th wheel jewel hole.
The stripped main-plate, dirty but in very good condition.
The parts of the disassembled watch.
The watch disassembled, and ready for further restoration work.
The bottom pivot of the third wheel will be measured.
The bottom pivot (that seen when you turn the movement around) measures 0.215mm in diameter (here the reading is slightly off due to holding the camera and the pivot is at an angle).
The wheel is held by the pinion, and the broken pinion is bored with a larger diameter.
A plug pivot is turned. Here i turn the larger end to make sure the plug fits snug onto the hole drilled in the pinion.
I will reduce it slightly more, and the final diameter will be arrived on the Jacot tool.
The pivot plug is ready to be parted off.
Here I'm testing the fit of the new plug pivot to the hole made. While mathematically the diameters should be .01mm difference, when driling the hole there is always lateral vibration of the tool, so a test is always made before parting.
I've parted the pivot, and staked it into the pinion.
The diameter is reduced slightly by burnishing very carefully. One risks, via the torsion created by the burnisher, that the plug is loosened.
Checking the fit and seating of the new pivot on the 1/3 plate.
The other end of the pinion.
Moving onto the geartrain check. First reattaching the 1/3 plate on on the mainplate.
1/3 plate screwed on.
Checking seating again of the 3rd wheel.
Checking initial play with the center wheel.
Adding the 4th wheel.
Mainspring added.
There is very good play (see detail of the 4th wheel teeth spinning).
The 3rd and 4th wheel pivots seen through top of movement.
Here is the 3rd wheel nestled in the other gears.
The right hand side of the gear is where the new pivot is. It's terminal point needs to be dressed and polished.
I start to examine the top balance wheel jewel, since that pivot is bent.
Disassembling the jewels, the screws are not original, and the jewel setting has been tempered with in the past.
The jewel is dirty, and also, the bottom screw thread is filled with grit. Not a good sign.
The jewel is filled with broken metal dust from the pivot, the broken jewel cut into the pivot (you can see the cracks running along). A new jewel will be sourced.
The pivot diameters are measured.
A picture of the placement of the hairspring stud, this effects timing. After the new balance staff its position will need to be slightly adjusted, but having this reference facilitates this task.
On high quality English watches, the hairspring stud is not circular and made of brass like in the Swiss watches, but of steel, and rectangular to facilitate its fine positioning on the balance staff.
After removal of the hairspring, I see that this is a replacement staff. It is 'black' because it has a brass sleeve, typical of a 1st half of the 20th century replacement staff.
Making measurements on the micrometer dial gauge.
Removing the roller, and the underside of the balance staff.
Staking off the staff in a staking tool.
Double checking measurements with the balance off.
The size of the pivot, given that its a replacement, it is very likely that many of these measurements will have to be adjusted based on how the balance sits on the watch itself.
Starting the balance staff with a blued steel 2mm diameter rod on the lathe, with the cross slide.
Visual inspection and comparison for the inital cuts.
On a piece of glass, using various grits of sandpaper I sharpen the hand gravers.
Rough state.
Polishing the graver on oilstone for a better and cleaner cut.
Using the graver and starting to turn a rough top pivot.
Quick comparison using the first staff for pivot length.
Measuring pivot thicnesses, here arriving at the hairspring stud seat (which was at .68mm, here this reads roughly .698mm diameter). So some more metal is removed.
Intermediate stage before balance seat is turned (the staff still needs to be burnished and polished on the Jacot tool).
Test fitting the balance staff.
Inspecting the original staff on the measuring microscope, we see that it is in very poor condition, and slightly out of concentricity (meaning it was turned round when made, and not all in one go as I will do here, more on this in the subsequent update).
A new balance staff jewel is chosen, because the original developed a crack in it. A new jewel is taken from a vintage English movement that was previously ruined.
Finding a suitable jewel using an old staff from this watch.
A selection of candidates. The chaton (brass bushing) needs to be shaped to size.
The jewel is cemented onto a wax chuck - traditionally wax was used to cement the pieces onto the chuck.
The outer diameter turned.
The jewel chaton turned to size.
Fitted onto the top of movement 1/3 plate.
Examining the depth of the jewel chaton.
Further view.
Various problems were evidenced when the watch was tested. The holding screw of the balance staff jewel cap was threaded, and a new screw was shaped for it from old stock.
The head reduced and shaped like the original.
Spotting the screw to indicate its position.
English screws had positional marks on them, to help maintain the exact conditions of a watch after adjustment.
Turning one of the many staffs.
Staff previous to finishing.
Fitting the balance wheel.
Burnishing the pivots to size.
Initial testing of the balance pivot lengths with the movement dissassembled.
First tests with movement assembled.
Throughout the testing period, I turned and adjusted many staffs, until I was able to adjust a satisfactory performing balance.
The watch during pre-wrist testing.
The watch is tested on the wrist, here seen with the glass temporary fixed with tape.
On the wrist testing with plastic protective covering.
