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Felsa 1560 Bidynator

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Just finished servicing one of these as part of a task set by my Horology tutor.

Thought I wold give a quick walk through as it is an interesting and very good movement that can be had fairly cheaply.


The Bidynator was the first Bi-Directional auto movement (Felsa 690) introduced I believe in the 1940's. This is the later 1560 calibre.


Here is the rotor that is removed by moving the tiny spring loaded lever down and left to unlock it. This is indicated on the rotor by a small arrow.



With the rotor removed the auto plate is revealed. You can also see it has Incabloc shock protection and the escape wheel has capped jewels.



Auto plate removed revealing the bi-directional auto module. This movement has 2 clicks, the one on the auto module does not let the power down. The click to let down the power is located at the 2 o'clock position in this picture resting against the barrel  ;)



With the plate removed the gear train is exposed, notice the twin gears on the third wheel. The lower wheel is slightly offset to the top wheel. These engage with the (indirect drive) centre seconds pinion to prevent stutter I guess?


I didn't photo inside the barrel when I took it apart but it has a conventional mainspring hooking, but there is a separate slipping bridle that runs around the inside rim of the barrel. The mainspring hooking, hooks on to this and this provides the slipping mainspring that is required for a automatic movement.

The slipping bridle is removed during cleaning and braking grease apple to the barrel wall before re-assembly.

NOTE: The mainspring winds in reverse to the more common mainsprings (ETA's etc) This caused a problem with my mainspring winder that can only wind in one direction (Bergeon..Hah!) So it was hand wound in which was quite straight forward.


When the gear train has been removed there is a final bridge holding the centre wheel in place.




Flipping over the movement reveals a straight forward motion works and keyless setup. Again you see the capped jewel escapement and look at that shock setting, this is a well made, good quality movement ;)




Lubricants used were, 
Auto module and rotor 9010
Gear train D5 & 9010, 9415 on the pallets
Mainspring wiped with D5, Barrel wall 8213 braking grease
Keyless and motion works D5 & Molykote DX
The movement is performing very well with a 48hr power reserve. I don't have a timegrapher at home so regulated it with a digital stopwatch as close as I could. It is still within a minute, 3 days later, being worn all day on the wrist...Impressive.
Here's the completed watch.





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Mainspring reversed compared to eta is easy to solve with this trick.


wind the spring upside down in a holder one size smaller. After the spring is fully in that holder transer the spring to the correct size holder by putting the holders face to face and push the plunger. Now the spring is in the proper direction and you can push him in the barrel. Simple trick but works nearly always.




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Sudden thread resurrection! To complete the miracle, let's have a guess game, in the picture below there is a feature that has become obsolete since many decades, what it is?

Beginners only experts please abstain from answering :)


On 4/9/2015 at 11:23 PM, jaycey said:



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Nice walkthrough Jaycee a movement I have not seen before. The barrel/ mainspring set up is interesting. If I have a  winding in the correct direction issue I just wind the spring in the wrong direction then I then push the spring into a suitable washer, turn over the washer & push the spring into the barrel (The same method used with a new spring)

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