How to replacing magnetic rotor in a Quartz movement

[chris141058]

I acquired a quartz watch with a basic 5Y23 movement where the second hand could be seen to be twitching as if trying to move but wasn't able to.
Thinking that it was jammed up with crusty oil I stripped it down and oilded the movement (guessing where to oil it as I could not find a guide anywhere).
All went well except for locating the magnetic rotor. You can see from the image below taken during the strip down that the rotor (arrowed) is centred in the circular hole in the plate around it. However, when I come to put it back I cannot locate it centrally. It is magnetic so gets attracted to the bits of metal around it and does not want to locate properly.
Anyone got any good methods for locating it correctly?
Thanks
Chris

 

[Joe Horner]

All you can do is set it carefully, making sure the lower pivot is in place, then try not to disturb it while refitting the top plate.  It's often easier if you remove the circuit / coil for better clearance and less risk of damaging the coil.  Obviously, that depends on it being possible to refit the circuit / coil once the plate's in place

You'll also find it a LOT easier with properly non-magnetic tweezers - Dumont Dumostar (a stainless steel that won't attract magnets) or Super Hi-Tec (titanium and my personal faves for this job) both help a lot if you can justify buying them in the first place.

[rileynp]

Sometimes you can place a small steel screw on the dial side of the main plate, over the jewel for the rotor.  It will draw the rotor towards it and help keep it centered while you install the train bridge.  I also use a small brass pick (like the size of an oiler) to help coax the train and rotor into place before tightening the train bridge screws down.  You can start the screws in their holes, but you need to make absolutely sure all pivots are in place before applying any force to the bridge.

[Joe Horner]

I also use a small brass pick (like the size of an oiler) to help coax the train and rotor into place before tightening the train bridge screws down.

Close on 20 years in this job, and there's still things to learn out there - I like that tip, thanks 

[7s26b]

Hi Joe, the tech pdf for the 5y23 is in the forum resources, look for  Seiko technical manuals, it's on the first page.

[chris141058]

Thanks for the tips guys. You have given me more confidence to continue playing with this baby. I hate to be defeated (even for something that is relatively worthless - I guess this is what makes this a hoby and not a profession).
It might be a good excuse to buy some nice new titanium tweezers.
Chris

[nzwatchdoctor]

Before putting the top plate back on re clean it. Quartz movements shouldn't be oiled imho and having done countless overhauls on quartz movemnts where the only thing stopping them was the old oil 
 
Good luck   
 

[pollyc]

I was playing with a 7123 yesterday, my first venture into quartz fiddling.  Getting the gear train bridge on and all the staffs in their bearings was a royal pain in the arse.  It took me two hours (and I did swear a bit but carried on for the learning practice).


With basic tools only I got all the cogs and stepper rotor lined up as best as I could and lowered on the gear train bridge, put in the screws and did them up loosely just to hold things in place and then using strong magnification pushed each staff into its bearing with a slim needle.  I could only do this visually so good light and magnification is essential.


Also it was necessary to remove the circuit board and coil for access.




I think I prefer manual/auto watches


Mike

[Joe Horner]

... having done countless overhauls on quartz movemnts where the only thing stopping them was the old oil 
 
Good luck 

The other way to look at it is that the reason the only thing stopping them is the oil is exactly because old oil will stop them before they wear.

With "properly" built quartz using metal pivots and plates (or even jewels) there may be an argument for not oiling because of the very low wear rates but the usual plastic pivots / plates -or even a mix of metal and plastic (worse imho) - without oil will keep running until they're too worn to work.  Correctly oiled they'll stop before that happens

[chris141058]

Mike, sounds like you and I were in a similar situation - this was also my first quartz rebuild, hence the newby question originally.
Having seen all the wise comments I had a quick play last night. I managed to get the rotor back in place fairly easily. I found I manoevered it best if I held it with the tweazers at right angles to the staffs.
I then carefully lined everything up and got the cogs to engage with each other. Then, maybe I was just lucky but when I lowered the bridge over the screw holes the staffs slotted right into place without any fiddling. Yeaha. Then put the rest of the watch back together without any difficlties.
Chris

[pollyc]

   you were very luck, them holes are so small.


mike