You know what? I think we are getting somewhere. This has been somewhat of a marathon of the unfamiliar, taking me into pastures new involving rather more improvisation and compromise than I am generally prepared to accept in any single watch project. The nature of the beast in this case though has meant that compromise was always on the cards from the start and the end result has to be one whose measure of success bears that in mind. The process from start to finish has taken 8 months, with serious endeavour starting in early November. When last we met our patient, its movement had been dismantled, cleaned and rebuilt, with absent parts located and fitted but it remained untested other than establishing that it ran with strong timegrapher figures.
If you cast your minds back to the setting of the scene last month, you will recall that the case was missing a number of essential elements, or, to be precise (to quote Thomson of Thompson & Thomson): the crown, one pusher, the case ring, all of the hands and the acrylic crystal.
Let’s start with the pushers. Given that we have one working original pusher but that a generic substitute is likely not to have exactly the same dimensions, my first decision was to replace both pushers to avoid ending up with a mismatched pair. With that decision made, the next head-scratcher for the uninitiated (i.e. me) involved ascertaining how the pusher pendant tube should be removed. The inner components are dismantled easily enough by unscrewing the threaded pusher from the inside of the case. The cap, its spring and the pusher can then be set to one side and attention turned to the pendant tube. With this design of case, the pendant tube is screwed into the case, its splined head aiding its fitting and removal. One word of caution: under no circumstances must you attempt to remove such a tube using anything other than the correct tool. If, for example, you attempt to unscrew it using a pair of pliers, you will almost certainly crush the tube, rendering it un-re-usable. Instead, purchase the correct tool and rejoice in your foresight as the tube is liberated from the case without so much as a whimper.
The original pushers have a 4mm cap and use a 2.5mm pendant thread and so this is what I ordered from Cousins. These pushers are not cheap and so it is best to be certain of your measurements before placing your order. Here is one of the two new pusher assemblies next to the outgoing original.
One of the advantages of the new pushers is that they come with fresh rubber gaskets, held in place by a washer on which will sit the pusher spring.
In order to fit the new tube, we set it into the spline tool, having first fitted the outer metal spacer gasket.
The next bit is easy. Screw in the pendant tube, taking care not to over-tighten and then repeat the process with the second tube.
I feel as though slowly but surely I am making some progress, but that impression is dented slightly by the realization that the new pushers are too long and will need to be adjusted. You can get a sense of what is required by comparing the original (below, lower) with the new (below, upper).
Test-fitting the new pusher provides a view of the extent to which it protrudes into the case when it is in its undepressed position.
It would appear that we need to remove a good millimeter and a half from the end of the pusher to ensure that its end sits flush with the inner circumference of the case. Once more, I find myself having to contemplate the purchase of additional tools to realize an objective. Removing material from the pusher is no big deal – I can do that by working the pusher against different grades of emory paper but I will then need to re-establish the screwdriver slot in its end. I am conscious that if I shorten the pusher first, making a clean, centred cut for the slot may then prove tricky and so the strategy I adopt is to first deepen the slot and then shorten the pusher. To do the former, I will need a slotting file of the correct thickness to cut a 0.35mm screw head slot. The tool I choose is a Vallorbe 1840 (Cut 8) whose expense I hope I will be able to recoup in the years to come (this being the first time in 10 years that I’ve needed to re-cut a screw head slot).
In the photo above, the slotting file is shown upper left and a small diamond file lower left. In the end, I decided against using the diamond file to shorten the screw because this could be accomplished easily enough using graded emory paper. Prior to each shortening iteration, I used the slotting file to deepen the screw head slot.
You can see quite clearly in the comparison below just how much material needed to be removed.
Repeating the process for the second pusher and we can test fit to check that the screw heads are now flush with the case.
The only way to check that I’ve done a proper job is to fit the movement and test the operation of the pushers.
Everything seems to operate smoothly and so I am satisfied that I can move on to thinking about how to locate and fit a suitable set of hands. In total I need the hour, minute and centre chronograph seconds as well as the minute register and running seconds register hands. The hand hole sizes for the Valjoux 7730 are 1.40 x 0.95 x 0.27 / 0.27 x 0.18. Few of these sizes are shared with commonly used modern (or even vintage) movements and much fewer still in the correct style and so some craft will be required. Generic register hands are available with hole sizes 0.26 mm and 0.17 mm, neither of which will fit out of the box but both of which should be broachable to fit properly. I order a set of ten of each, which should allow for plenty of trial and error to get the sizing right. Similarly, generic central sweep seconds hands in more or less the correct style come in 0.25 mm hole size and these too can be sized. The problem comes with the hour/minute hands because the closest hour hand hole size commonly available from watch materials houses is 1.2 mm and this is too far from the required 1.4 mm to be broachable without catastrophic results (I’ve tried). My only option on that front is to source a set of correct hands to fit the movement, accepting that the style will deviate somewhat from that of the originals.
First things first though. Let’s have a crack at broaching one of the register hands. For this I will need a set of very fine broaches.
I select a suitable size, thread a 0.17 mm register hand onto the broach and carefully work the hand around the broach (or vice verse) until the hand sits at a point on the broach whose diameter better duplicates that of the shaft of the fourth wheel.
Test fitting the hand to the shaft suggests a tad more material needs to be removed.
Fine tuning the fit will need to wait until the dial is back on but for the moment, having repeated the process to mate the minute register hand with the shaft of the minute recording runner, we now have two contenders, whose lengths have also been trimmed to fit the sub-dial diameters.
The next small hurdle requires me to size and fit the split stem. The close fit of the movement and case mean that with the movement in position, there is no view of the female end of the stem from above.
In some designs, the male and female parts are connected by aligning the female part and then slotting the two together as the movement is lowered into the case. With this case design though, the movement has to be fitted at a slant to enable the stem to clear the lip around the edge of the dial aperture. This means that the two parts have to be snapped together using a degree of brute force once the movement is in position. It is worth first peering down the crown tube to get a sense of how the inner stem is aligned before inserting the crown.
At this point in proceedings, the stem is not yet trimmed to size and so the crown needs to be fitted and removed a number of times before the correct length of stem is achieved. In the shot below, we see that the stem is still quite a bit too long.
Removing the crown is easier said than done at this point because of the difficulty in gaining sufficient purchase. Fortunately, my cannon pinion puller comes in handy.
If you are starting to think we are getting dangerously close to finishing this one, you’d be right! Happy with the sizing of the stem, it is time to fit the dial and register hands and test the functioning of the chronograph.
The presence of two sub-registers may suggest that this chronograph has both minute and hour registers but the register on the left hand side is just the running seconds, its shaft connected to the fourth wheel and which runs all the time. The minute register on the right hand side of course is part of the chronograph functionality, running from 1 to 45 minutes. The minute register hand needs to be fitted with the chronograph in its zeroed position, the hammer keeping the minute runner in its reset position. With some power wound in, the movement is up and running and I can test the operation of the two pushers properly for the first time. Happily, the minute register starts, stops and resets in line with the commands dictated by the two pushers. I am clear to proceed with the fitting of the minute and hour hands.
I have forgotten to mention that I managed (last week in fact) to locate a set of Breitling Top Time hands at very modest expense. The only minor fly in the ointment is that they are not of the correct style for this watch and they are both a tad on the short side but beggars can’t be choosers and I am actually pretty pleased with the overall effect with the hands in position.
You’ll notice too that the seconds hand is fitted. I had spent quite some time getting the height of all three hands right to avoid the seconds hand fouling. Satisfied that all runs true, I can now check that the seconds hand stays on its post when the chronograph is reset (which it does).
We have two tasks left. First place the index ring.
The index ring would normally be secured in position by the sprung dial ring that would have slotted into the groove around the edge of the aperture in the case. Unfortunately, this was one of the numerous missing parts and a replacement is impossible to source. I am confident however that the tension ring-equipped crystal will serve the same purpose. Happily, this expectation is born out in practice.
I had re-regulated the watch before fitting the crystal and am happy both with the amplitude and timekeeping. The movement is running with a touch of beat error (0.2 ms) but I can live with that. As always, our final task is to locate a suitable strap. The lugs are 19mm apart and the only new strap I have in that fitting happens suit the watch rather well.
A domed acrylic is always worth appreciating in profile.
And lastly, a moody glamour shot, showing off the cosmetic flaws to the dial to rather good effect. I will keep my eyes peeled for a correct set of hands and maybe a correct crown but for the moment, I am hugely satisfied with the outcome and more than content to use and enjoy this watch to an extent that I hope makes up for the years it has spent partially dismantled in a retired watchmakers parts bin.