Felsa 4002

 
Felsa 4002

Felsa 4002

Description

In the early 1960ies, Felsa released their one but last series of selfwinding movements, and they could be seen as the top of their movement developments.

The Felsa 4002 is the model with date indication, but without a quickset function.

base plate

base plate

The visually most applealing type was gilt, which perfectly matches the rich equipment with ruby bearings. Except the non friction-prone bearing of the mainspring barrel, all bearings are of course ruby-equipped.

It’s striking, how few place the gear train and balance use; about one third of the available space remains unused.

minute wheel bridge

minute wheel bridge

The directly driven center minute wheel is beared under an own bridge. This kind of construction was no longer really cutting edge technology, but it was proven for decades.

inner side of the gear train bridge

inner side of the gear train bridge

Interestingly, the crown wheel is not part of the winding bridge, but is located on the inner side of the gear train bridge.

gear train

gear train

We have an old-fashioned gear train on the Felsa 4002: The large mainspring barrel drives the center minute wheel, followed by third wheel, seconds wheel (at 6 o’clock, so in theory, it could carry a decentral seconds hand on the dial side) and finally the steel escape wheel.

The third wheel consists of two concentric gears of equal side, but having a little offset, so tha the center seconds pinion does not flutter or jump. It works perfectly!

side view of the gear train

side view of the gear train

On the specimen shown here, the balance wheel is top quality, it is a large Glucydur screw balance. It’s a bit sad, than only a flat hairspring was used, and that there’s no fine adjustment of the hairspring length possible. The precise beating frequency of 18000 A/h can only be adjusted with the hairspring key directly. It would have been the icingon the cake, if Felsa hat used a Breguet hairspring with a swan neck regulator.

Of course, the balance wheel is shock protected. It cannot be determined with certainly, which type of two-leg shock protection is used here.

without selfwinding module

without selfwinding module

Without selfwinding module, the Felsa 4002 is equal to the Felsa 4012. You can nicely see, how the engagement of the selfwinding module with the crown wheel happens at position 8:30.

inside selfwinding module

inside selfwinding module

The selfwinding module consists of a rocking bar changer, a transmission wheel, which is secured by a ratchet plus click spring, and the transmission wheel, which drives the crown wheel.

The dead angle of the oscillating weight is pretty big with about 60°.

mounted selfwinding module without oscillating weight

mounted selfwinding module without oscillating weight

Both transmissions wheels are fully ruby beared, but not the two wheels of the rocking bar changer.

On manual winding, the decoupling of the rotor happens on the rocking bar changer, which means, that the two transmission wheels and the ratchet have got a lot to do. No idea, why Felsa did not use for example a beguet clutch on the first transmission wheel. A small faux-pas on the otherwise so well constructed movement.

inside the oscillating weight

inside the oscillating weight

Pretty usual for Felsa was, that the oscillating weight is axle-beared. It has got a heavy metal inlay, probably lead.

oscillating weight

oscillating weight

The fixed axle runs within the ruby bearing of the oscillating weight. It is mounted with three screws and in case of a breakage, it can be exchanged easily, as long, as spare parts are available.

calender mechanism

calender mechanism

The calendar mechanism on the Felsa 4002 is pretty simple and has got no correction mechanism at all. So, in a bad case, you have to turn the time forth or back for fifteen days to reach the correct date. Later versions of the movement (caliber Felsa 4007) at least offered a semi fast correcting mechanism.

On the other hand, the locking of the date ring is very well made: A flat and beared metal ring is pressed against the teeth of the date ring with the help of a secured spring. No flying parts, that’s what watchmakers love!

Felsa 4002: Dial side

Felsa 4002: Dial side

The setting lever of the Felsa impressed with its very rugged construction, and so, the dial side also offers a very pleasant view for the watchmakers’ eye.

In the lab

The specimen shown here came gummed and with a large beat error into the lab. It was a movement without case, because it most probably had a golden case, which was melted and destroyed. What a pity!

It was cleaned, olied and adjusted.

Timegrapher result

For the fact that the work was in rather bad condition ("slaughter movements" are usually not handled carefully), and already 60 years old, it showed exceptionally good precision values on the timegrapher. In five of the six position, the daily deviation is lower than ten seconds, and the constantly low beat error on all positions also are a proof for the high quality of this movement.

horizontal positions
dial up +17 s/d 245° 0.1ms
dial down -7 s/d 298° 0.3ms
vertical positions
crown right (12 up) -4 s/d 213° 0.2ms
crown up (3 up) +5 s/d 209° 0.3ms
crown left (6 up) -9 s/d 202° 0.1ms
crown down (9 up) -9 s/d 204° 0.4ms

Technical data

Manufacturer:Felsa
Caliber:4002
Number of jewels:25
Escapement:Pallet lever
Balance types: Glucydur screw balance
Shock protection(s): 2 legs (generic)
Balance bearing / direction hairspring:Clockwise
Moveable stud:yes
Adjust mechanism:Hairspring key
Construction:
  • lever
  • escape wheel, seconds wheel, third wheel, center second pinion
  • center minute wheel
  • mainspring barrel
Construction type:solid construction
Winding mechanism:yoke winding system
Setting lever spring:1 hole(s)
Features:SCI,QG,AUT
Functions:hour, minute, second, day, selfwinding
A/h:18000
Size:11 1/2'''
Literature: Flume: K2 1962 71
Inventory number:20001

Usage gallery

Saturne de Luxe gents watch (case missing)

Saturne de Luxe gents watch (case missing)