Second wheel endshake

[spazthecat]

Hi,

I've got an old ETA 2783 that I'm cleaning and rebuilding and have a little problem I'm not sure how to handle.

When the train bridge is seated, the second wheel floats vertically a lot which results in it coming out of its jewel on the train bridge subsequently binding up the whole train.

I've checked the bridge and it doesn't look bent. The intermediate wheel, escape wheel, and third wheel are all seated properly. The second wheel jewel looks to be at the correct depth in the train bridge.

Is the only solution to adjust the jewel depths for intermediate, third, and escape wheel?

Not sure what else to look at.

Thanks,
Andy


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[spankster23]

1 or both of the pivots on the second wheel are broken is my guess.

 

[spazthecat]

Thanks for the reply, but. That's not it sadly. The second wheel is new and I tried it out in a working movement to validate its ok.

I'm leaning toward the train bridge being deformed but not enough to see well. It seems to be level when I look at it but depending on the viewing angle, maybe not so much....


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[ItalianSub]

So...what it sounds like you're saying is there's too much end shake? What is keeping you from adjusting the jewel height to see if it keeps things in order?


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[ItalianSub]

Another thing...are you sure the jewel isn't cracked? Maybe there's a spot where it's allowing the pivot to slide out...another thing...the seconds wheel is a B to seat. You're sure it's all seated properly?? I remember thinking the same thing once...then after adjusting the wheels for about 30 minutes it all slipped into the right spot and they stayed put.




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[spazthecat]

Correct. Too much end shake. The second wheel moves up and down too much resulting in its pivot sliding out the jewel on the train bridge. I've adjusted the depth of the jewels for the entire train bridge as best I can but I'm hesitant to adjust further because I don't have the proper tools to do it. The jewel looks good to me.

I'm sure everything else is seated properly as there is no horizontal movement in the others and when I have the movement dial side up, the entire gear train is fine.


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[ado213]

I'd agree, your train bridge is bent, lay it on a piece of glass or a mirror, it may be possible to measure or see the bend. This can happen when the centre second hand has been pressed down too hard when fitting. Use of the correct movement holder alleviates this potential problem.

To clarify, there are two types of clearance on a jewel and pinion, end float and end shake. Float being vertical and shake being horizontal

hope tis helps