Large variations in rate

[Lc130]

Hi All

I'm learning on an AS 1700.  I disassembled, cleaned, oiled to best of my beginner ability and reassembled. I didn't change or attempt to clean the mainspring. 

On the timegrapher the rate varies tremendously from +900 to +132.  Over the course of several minutes it varied +130 to +200.

The amplitude varies from 175 to 235.  The beat error varies from 0.7 to 1.8. 

Would this be attributed to the mainspring or something else?

Thank you for any comments,

Charlie

 

 

 

[qhartman]

I'm also a rookie, but I would expect large variation in amplitude to be a problem with the balance wheel, or with something along the gear train causing inconsistent power delivery, not a problem with the mainspring itself. Anxious to hear what more experienced folks have to say too!

[yankeedog]

rate of fluctuation ? how many seconds? very short intervals look at your escape wheel , longer intervals fourth wheel, maybe  something out of true or round or wobbling

Edited January 2, 2019 by yankeedog
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[oldhippy]

You should have cleaned the m/spring. Without looking at it you do not know what the condition of it. What oil have you used on the train and the escapement, you might have used too much. These are just two of many things why the movement is keeping erratic time.

[Nucejoe]

AS 1700 features detached manual wind with corresponding gear underneath barrel. Barrel and mainspring are part of power train, should be cleaned and lubed as OH advised

Periodic rate fluctuation is sinusoidal, which corresponds with period of each wheel and barrel to whcih yankee refered. Non-periodic fluctuations are to be attributed to loose objects affecting the power transfer in the train ie;  broken pieces, loose screw, dirt.  As well as grooves in barrel lid or bottom plate.

" over the course of several minutes".  is talking to us, several minutes is beyond the period of escape and minute wheel  so the answer to your question is YES it can be attributed to mainspring and barrel mostly on account of dirt or grooves.

Before removing the barrel, use the manual wind readily at your disposal to bring the MS  to full wind, observe how long it runs ( actual power reserve) gives an idea of MS strength. It may need a new mainspring too.

 

[rodabod]

+900s? I'd be looking at the hairspring first. Make sure it is clean and that none of the coils foul each other or anything else.

[nickelsilver]

As above, this could be any number of things. You have to go through systematically: check the train freedom, check that the pallet fork is free, check that the balance is free (minus pallet fork). In all likelihood it should run fairly well, even with an unserviced barrel,  definitely better than what you have. Like rodabod said, with such a huge gain there is almost certainly an issue with the hairspring- but don't mess around there until you've done all the basic checks. And do, do peg out the jewel holes- particularly the hole jewels for the fork.

[oldhippy]

It always good practise to demagnetise the watch and any tools you are going to use first. Seiko barrels are made in such a way that they should not be opened, The practise years ago was to replace the whole unit every (I think 5 years) because many complete units have become obsolete you have no alternative but to open the barrel and replace the spring if needed.     

[rodabod]

I should have also added to check that the hairspring and movement are not magnetised.

The only other time I can remember experiencing an extreme gain in rate other than "knocking the bankings" (due to excess amplitude) was when I had a safety roller which wasn't playing ball with the pallet that caused a similar effect by causing the balance wheel to immediately bounce back every time it swung in one direction.

[Lc130]

Thank you all for the help!  I disassembled and reinspected the wheels which appear to be true.  I did not peg out the jewel holes and will do that.  

I used Mobius 8000 oil which I was told would be sufficient for learning.  

Below are pics of the mainspring.  Should it be replaced or will a cleaning do?  Does this spring need a breaking grease in the barrel?

Thank you

Charlie

 

 

[oldhippy]

I don’t know if it is the photo, the spring looks wrong between the two red arrows. It certainly is extremely dirty.  

[yankeedog]

It certainly is nasty. A cleaning might do.