ETA 7750 - UNI or BI Directional winding

[Philoupke]

So I've done quite some research on this VERY basic question but can't seem to find a decent answer.

Found the following info

1: VJ 7750 is uni directional, the rotor spinning freely counter clockwise and has resistance because of the mainspring winding in clockwise direction.

2: ETA 7750 is bi directional, the rotor winds the mainspring in both directions.

So firstly, is this info correct?

Then secondy: in the case of an ETA 7750, I'm guessing it's a pretty free spin in both directions then?


Sent from tapatalk

 

[KBH]

I always thought they were both the same. Rotor only winds in one direction. I could easily be wrong on that one though so I'm interested in hearing more.

 

[jai04]

As far as I know, both of them are uni-directional.

 

[trailboss99]

Both are uni-directional, clockwise. If on a winder you need about 900 turns a day to keep 'em wound.

 

[Philoupke]

On my eta 7750 it looks like there's a free spin in both directions. But it's brand new!

What could that be? Since I would rather not open the case I slowly hand-wound the watch to see if the gears were missing teeth, but it didn't appear to be the case.. Any tips?


Sent from tapatalk

 

[chris3007]

Here you can see the 7750 just wind in one direction

https://vimeo.com/140679956


Sent from my iPhone 6

 

[Philoupke]

This is how mine turns:

I don't hear the ticking noise when I slowly let it turn.

What do you think?

 

[KBH]

You shouldn't be hearing a ticking noise anyway. And it's normal to free spin in one direction. Does it keep running when you wear it? If so, it's working.

 

[Philoupke]

You shouldn't be hearing a ticking noise anyway. And it's normal to free spin in one direction. Does it keep running when you wear it? If so, it's working.

Well I tested that monday to tuesday. Hand wound it monday morning, stopped working tuesday around noon.

Natas78 is going to have a look at it with his watchmaker teacher so I'll find out soon enough! But since I didn't have any resistance in clockwise direction and it stopped working midday I'm assuming it doesn't wind with the rotor!


Sent from tapatalk