Wristwatch restoration, servicing and repair

Posts Tagged ‘Venus’

Fortis Centinela Alarm (Venus Cal. 230)…

It’s been a while since I’ve written about an alarm watch on the blog, so let’s have a look at this Fortis Centinela.

(Click pictures to enlarge)

Fortis was founded in 1912 in Grenchen by Walter Vogt who had developed his watchmaking skills whilst working for Eterna. Probably best known for their modern Flieger and aviation inspired chronograph watches, Fortis have an interesting vintage history which included working with English watchmaker John Harwood on the development and release of the first ever automatic watch in 1926, developing the first waterproof alarm chronometer in 1956 and the first Swiss made plastic cased watch, the Flipper, in 1967.

The watch in this post is something of a ground breaker too as it was Fortis’ first ever alarm watch. Introduced in 1954 the Centinela had a production run of just 2 years before being replaced by the less complicated, A.Schild Cal. 1475 powered Manager model, making the Centinela something of a rarity.

Turning the watch over the caseback is unusual as it has a number of holes in it, effectively creating an echo chamber for the alarm…

… and under the screwdown outer caseback is a sounding plate with a pin mounted on the inside which is struck by the alarm hammer, causing the plate to resonate when the alarm is ringing.

Inside the watch is a Venus cal. 230, a 21 jewel, manually wound alarm calibre with a beat rate of 18,000 bph.

The watch arrived in non-running condition and the reason was immediately obvious. As you can see above, the ratchet wheel screw had sheared off inside the barrel arbor and the ratchet wheel was rattling around inside the case.

The Venus cal. 230 is an unusual alarm calibre as it only has a single mainspring barrel powering both the alarm and the going train. The calibre also has an uncommon dial aperture showing the alarm state; green for on, red for off.

In operation, the crown at 3 winds the mainspring and sets the time and the crown at 4 is used to set the alarm time and to enable/disable the alarm.

Let’s have a look at how it works…

When winding the watch the first four complete revolutions of the barrel arbor set up the power source for the alarm. Under the ratchet wheel is the alarm stop wheel which controls the release of power when the alarm is triggered. When fully wound the missing teeth in the stop wheel allow the arbor/mainspring to be wound further to power the going train. The alarm stop wheel also acts as the click in a regular watch preventing the mainspring from unwinding.

When the alarm is triggered, power is released from the arbor end of the mainspring until the alarm stop wheel reaches its unwound state; a very clever way of powering the alarm as the going train continues to run while the alarm is sounding. It does however have an effect on the overall power reserve, the alarm sounds for 10 seconds which costs around 12hrs of reserve. The reserve and alarm can of course be topped up again by winding the watch.

When the alarm is triggered the ratchet wheel rotates counter-clockwise, transferring power through the intermediate and alarm wheels to the alarm hammer which rocks back and forth, the two pins on top striking the pin in the sounding plate on the case.

This calibre is also reasonably complicated under the dial. With the top plate removed you can see the alarm setting wheels and the green and red painted sections on the alarm bolt yoke which are visible through the dial aperture.

The release mechanism works the same way as the Seiko’s Bell-Matic calibre in that the unlocking wheel has three cut-outs which correspond to three raised sections on the hour wheel as seen below.

When the raised sections and the holes in the unlocking wheel align (in other words, the alarm time is reached) the hour wheel rises along with the disconnecting lever underneath, freeing the alarm hammer on the other side of the movement, releasing power from the mainspring and sounding the alarm as detailed above.

Aside from the sheared off ratchet wheel screw, the shaft of which was stuck fast inside the barrel arbor resulting in a replacement arbor being needed, the rest of the service was straight forward, so once the case had been cleaned and a new crystal fitted, the watch could be rebuilt.

At 38mm this is quite a large watch, especially for the 1950’s. It wears well and would make an interesting addition to any collection, the hard part may be finding one.

Rich.

** Many thanks to Kevin Fuller for letting me feature his watch on the blog. **


Poljot ‘Strela’ Chronograph (Poljot Cal. 3017)…

There haven’t been many Russian watches on the blog, but this Poljot chronograph is something of a classic.

(Click pictures to enlarge)

Known as the ‘Strela’ (which is Russian for ‘Arrow’) these watches were originally developed for Russian Air Force Officers and were constructed to strict military specifications. They were only available to Senior Military, Government and Party officials, and were not for sale to the general public.

They were also used by several Russian Cosmonauts in the early days of Russian space exploration, the most notable of which has to be Aleksej Leonov who was wearing a Strela during the first ever space walk on 18th March 1965.

The Strela in this post is one of the early models which is fitted with a Poljot cal. 3017 column wheel chronograph, based on the Swiss Venus cal. 150. Around 100,000 of the cal. 3017 powered Strelas were manufactured over a period of 20 years before the movement was switched to a cam lever chronograph, the Poljot cal. 3133 (based on the Valjoux cal. 7733) in 1979.

You will see these watches branded either Poljot or Sekonda and they were produced with either a black or a white dial. (Sekonda is actually a British company that was set up in 1966 to distribute Russian watches in the West).

This watch arrived in a non-running condition as the result of a fall, the crystal was broken and the watch would no longer wind or run. A watch hitting the floor is never a good thing, but with this watch, like many vintage watches, it has no built in shock protection for the pivots on the balance staff.  Being the thinnest pivots in the watch, a heavy impact can easily snap off one (or both) of the staff pivots resulting in a much more complicated repair.

However, that wasn’t the case this time as the only parts damaged, apart from the crystal, were a screw securing one of the case clamps (the broken head and clamp had fallen into the movement stopping the watch), and the setting lever spring on the dial side.

After sourcing replacement parts, the rest of the movement was serviced, the case cleaned, and a new crystal fitted. The last thing to do was to remove the corrosion from the hands (you may have noticed in the first picture that the hands had corroded – not surprising really as this watch has no gaskets.)

It wasn’t possible to fully restore them as the corrosion had eaten right through the chrome plating, but they are much improved.

Rich.

** Many thanks to Jeroen Regouw for letting me feature his watch on the blog. **

You will see these watches branded either Poljot or Sekonda and were made with either a black or a white dial. (Sekonda is actually a British company that was set up in 1966 to distribute Russian watches in the west).

Breitling Premier (Venus Cal. 175)…

Here’s a great looking vintage Breitling that deserved some attention. These Premier chronographs are becoming quite collectible these days.

(Click pictures to enlarge)

‘Premier’ models were introduced during the 1930’s and were a long standing name in the Breitling lineup. Apart from two register chronographs, the lineup also included three register chronographs and elegant sub-second dress watches.  The name was retired in the 1960’s, but was re-introduced by Breitling between 1996 and 1999 in a limited edition production run of around 5000 watches. The re-issued model was fitted with Breitling’s own Cal. B40, based on an ETA Cal. 2892 with a Kelek chronograph module added.

Dating the one in this post proved to be quite easy as the engraved caseback gave a heavy hint as to its age. Quite a nice prize for winning the Class “B” league, I’m sure you’ll agree… I wonder what the Class “A” Champs got?. Using the serial number dated it precisely to 1946. (If you are interested in dating your own vintage Breitling, you can do so here.)

Over its production span, the Premier was fitted with a variety of chronograph calibres. Removing the caseback on this one revealed a quite tired looking, but complete Venus Cal. 175…

Most calibres are marked under the balance wheel with the manufacturer’s trademark and calibre number, but that wasn’t the case here. The dial and hands had to be removed first before the identity of the calibre was revealed.

The watch wasn’t running on arrival and obviously hadn’t been serviced for quite some time. Just to add to the fun, the hairspring had also been damaged, which proved even more entertaining as it was a Breguet overcoil rather than a flat hairspring (I wrote about the difference between the two types in this post).  After spending some time on it with the fine tweezers, everything was back in order again and the rest of the movement just needed a regular service.

Here is the watch after a clean and light buff for the case, and fitting a new crystal…

Rich.

** Many thanks to Helge Johnsen for letting me feature his watch on the blog. **


L.A. Leuba Chronograph (Venus Cal. 188)…

Another vintage chronograph, this time from the Swiss company L.A. Leuba…

L.A. Leuba is short for “Louis A. Leuba”, a company which surprisingly had no association with the much larger and well known Swiss manufacturer, Favre-Leuba.

The movement in this watch is a Venus cal. 188, a popular cam-lever chronograph calibre produced between 1949 and 1966 and can be found in many of the chronographs from that period.

After production ceased the design was used again by Valjoux in their cal. 7730 (the only modification was to the stud carrier, making it moveable to make beat correction easier). A few years later the design of the cal. 7730 was refined further and became the calibres 7733 and 7734 widely used throughout the 1970’s. Looking at a Venus 188 and a Valjoux 7734 side by side, it’s not hard to spot the lineage…

This particular watch arrived with a winding problem; it could be wound endlessly and the power reserve was less than 12 hours, which all pointed to a problem with the mainspring.

After removing the chronograph components it was plain to see that the mainspring had been heavily over oiled during the last service, the oil had leaking out all over the movement. However, after swimming through the oil the winding problem was quickly revealed, the mainspring had failed at the endpiece (inset)…

Judging by its condition, there is a good chance that this was the original carbon steel mainspring installed when the watch was first made. After many years of use (or less if you’re unlucky!) carbon steel springs can fail as they are susceptible to corrosion, often as a result of being handled during servicing. The problem is eliminated in modern mainsprings which are made from ‘white alloy’ (an alloy of cobalt, nickel, & chrome) and are corrosion resistant.

With a new white alloy mainspring ordered and installed, and the rest of the service completed, all that was left to do was renew the patchy lume on the hands. Although the dial shows its age a little, it has that great vintage look, and the movement is still in very good condition…

One last thing to notice about this watch are the three longer marks on the minute register at 3, 6 and 9 minutes. These marks were used to time telephone conversations back in the 1950’s when calls were charged in three minute intervals… if you talked for 10 minutes or more you probably couldn’t afford it!

Rich

** Many thanks to Marc Vos for letting me feature his watch on the blog. **