Should I Keep Trying On This Movement

[omgiv]

I just got done servicing this 3135 and am not truly happy with the final rate results.  I was hoping that the amplitude would be a tad bit higher.  This is borderline for me but the trace is pretty good and the delta is acceptable.  I would might adjust it a little more to slow it down a second or two.  I would rather see an amplitude of 290º in the flat positions.  I am wondering if I should try and see if I can eek out a few more degrees.  What would you do?

 

 

Sorry about the picture.  The screen was hard to capture well.

 

 

Thanks in advance!!!

[Mark]

It's natural to get a slight drop in amp when the pivots are resting on the edges of the jewel holes as there is more surface friction. If you are happy with the lubrication and you have de-magnetised the watch then you can start real-world testing.

Sent from my iPhone using Tapatalk

[omgiv]

Thanks Mark,

I am actually okay with the hanging positions. It is the flat positions that are on the low side. I have always kind of gone by the 270 flat and 240 hanging rule when it comes to amplitude.

I took a lot of care and am happy with the lubrication. The movement has also been demagnetized.

Would you be okay with these results? Thanks again!

[omgiv]

So...I decided that I wasn't entirely happy with the timing results since I serviced other 3135 movements and easily got 289-290 degrees in the flat positions. I decided to start over and recleaned and epilame treated it. I put it back together again and reoiled it and got about the same results. Nothing out of the mid 260's flat and also had a bigger delta.

I decided to start from the balance and work my way backwards to find where I am losing power. The hairspring is flat with even coils, has nice round polished pivots and seems to have good end shake. So, I then went to the pallet fork. Jewels are all clean with no cracks. Pivots are nice and polished and it seems to have good lock on all of the escape wheel teeth. I took the pallet fork off and decided to try the train. I put one click on the mainspring and the wheels turned but no backlash. It took about a 1/4 turn of the barrel to get good backlash. I have examined all of the wheels and only the great wheel seems to have some minor scoring on its lower pivot. It also seems to have a little more end shake.

I have found another great wheel but still have doubts about the third and second wheel (which is new). The only wheel, installed individually, that will spin freely long after a puff of air from the blower is the escape wheel. The other three wheels stop as soon as the puff of air stops. This makes me almost think that the train isn't as free as it should be.

I have cleaned it twice in an old L&R spinning machine and also in a L&R ultrasonic tank. I have pegged the jewels and even have run a smoothing broach through the jewels. All of the teeth and pinion leaves have been examined through a 60X scope. The only one that looked slightly off is the great wheel. I am a little stumped at this point because I don't know why the new second wheel won't spin as freely as the escape wheel.

I would appreciate any advice or insight that anyone would offer. Thanks!

[omgiv]

I decided to clean the whole thing again including pegging all of the jewels. I used peg wood and also a smoothing broach. When I was cleaning the upper great wheel jewel, I heard a faint noise and noticed some debris. What I thought was dried oil turned out to be flaked jewel. I am not sure if the broach caught on something or what why it didn't happen when I did it before. I didn't see any dried oil or debris under a 60X scope. But here is the broken jewel.

I had to order a new jewel and pressed it in with my jewel press and checked the end shake. I also decided to replace the great wheel since the jewel cracked and I saw some minor scoring. After all of that was done, all of the train wheels were truly free. Whew!

After oiling it again and doing some minor adjustments, I was able to get these results.

I still don't know why the amplitude isn't higher since I see 290-300 degrees frequently in magazine articles. But I also don't know how old this particular movement is. Overall, I am pretty happy with an average amplitude, a delta of 6 seconds, and an average rate of +1.3 seconds. Thanks for looking!

[No8yogi]

Nice work there always good to solve issues!

[Geo]

You are obviously very fussy and critical of your own work (not a bad thing) but I personally would have been very happy with your first results in the non-clinical real world.

I do have one question, is using a smoothing broach in a glass jewel really a good idea and normal practice? I am a mechanical engineer not a horologist and to me that seemed to be asking for trouble.

Great end result though!

[omgiv]

I will admit that I am a little OCD and have a hard time accepting defeat :). I usually only use pegwood for the jewels but had done that at least three times. I don't use broaches on jewels but did it as a last resort. There was something there keeping the wheel from spinning that the pegwood would not get out.

[fraggle42]

When you say 'it took about a 1/4 turn of the barrel to get good backlash' what do you mean by backlash in this context?

I'm familiar with everything else but this. Do you mean everything starts moving freely (as escapement was removed at this point) and then when wound down it stopped and reversed direction for a fraction indicating nice free movement?

[omgiv]

That is exactly what I was talking about. Turning the barrel set the train spinning since there was nothing to impede it. When the mainspring reached its end there was a recoil causing the gears to reverse slightly.

I had to turn the barrel a good bit to get this to happen so I had to see if I could find the reason.

[Lawson]

This is a great thread!  There is so much good information to absorb here and learn from ... Thanks for posting it Omgiv.

 

BTW ... there is nothing wrong with OCD my friend ... it's the sign of a craftsman at work :)

[rattandsonwatchmakers]

i must commend you....you have the  personality and drive  that i would want to hire...your attention to detail is very impressive

[clockboy]

In my early days of servicing watches I used to get very paranoid about amplitude and fiddled for many an hour without any improvement .

However I have found some movements just don,t have an high amplitude but run just fine. A very low amplitude is another matter but if possible I test the watch on my timing machine before the service so I have a before & after reference. 

Edited September 26, 2014 by clockboy

[bobm12]

Nice thread and nice job!

[omgiv]

Thanks for the comments guys. I am learning that there is only so much that can be done when servicing a movement. I know that there are naturally errors in the movement or low tolerances. I just want to make sure that I am not one of them :)