Strange behaviours for Eterna 1489K

[richiesgr]

Hi

May be someone can help me on this.

I've serviced an eternamatic 1000 movement 1489K automatic.

The watch work perfectly when there is no automatic weight attached like in picture 1 

But when I tight the screw of the weight on his axe (in red on the picture) the balance stop very like something was preventing the movement to run run freely the balance re-start normally when I unscrew this screw

How is it possible there should be no interaction between the automatic bridge and the train of wheel ?!?

I post some photo of the movement

Thanks

[gary17]

hey

Are you sure its the correct screw for the weight.

[Marc]

@gary17 just beat me to it, are you sure that it's the right screw?

It looks to me that if you're using a screw that's too long it will protrude below the bottom of the auto bridge and possibly foul the balance wheel or maybe another wheel in the train.

[watchweasol]

Does the rotor move freely when tightned up ?.  Was the movement working prior to being dismantled and cleaned ? If so then somthing has happened during thre cleaning  reassembly process , The above answers regarding the screw are the first check loosen off the screw a turn at a time and see when/if the balabce srarts, if so the screw is distorting the bridge stopping the movement.

[Nucejoe]

 The rotor gear could be pushing on gears of the auto device whereas they should mesh.

Loosen the screw so the balance starts tor run, then turn the rotor so to get the gear teeth to mesh and tighten back.

Another possibility is a longer screw will protrude furthure out the otherside and exerts stress on the auto device. 

[richiesgr]

Hi 

I've solved the problem by replacing the screw with a shorter one as mentioned. It's perfectly working I think someone before me have swapped the screws.

Thanks for your help