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Odd timegrapher results


ifibrin

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After disassembling, cleaning, reassembling and re-oiling a New old stock ETA 2641 movement, the performance appears fine, considering the complete barrel assembly was obtained from another donor movement at least 20 years old from a materials house in Singapore. This was because they didn’t carry any new sealed mainspring for the 2641, and only had a new unused complete barrel assembly from a donor movement.

The ETA 2641 I serviced appears to be a normal (not high grade) one, with a silver balance wheel. More problematic was the train bridge was fouling the teeth of the ratchet wheel in this NOS movement due to a metal lip on the train bridge facing the ratchet wheel; I shaved this metal lip off the train bridge to resolve the issue. I obtained another train bridge from the material house which did not have this lip of metal, suggesting that the later iterations of the ETA 2641 does not have this metal lip on the train bridge.

Horizontal positions for the movement have around 240 deg to 250 deg amplitude, with around +20 to +30 seconds per day variation (slightly erratic). Vertical positions have around 190 deg to 200 deg amplitude, variation ranging from -20 to 0 seconds per day. Beat error in both horizontal and vertical positions are usually 0.0 ms to 0.1  ms.

The main issue:

The timegrapher results occasionally shows extra dots above or below the main trace in various positions, but this doesn’t always show up, and can appear in different positions. When this noise shows up, the beat error increases from 0.0 ms to around 1ms, but I’ve seen it go to more than 2ms on occasion. I’m not sure if this is a correct beat error reading, or interference from the noise. What could cause such an issue?

 

5B81E167-CE4A-4339-B023-A95F2E3F6570.jpeg

DB5BCC84-5C36-419C-AD12-13BC3432D4AA.jpeg

Edited by ifibrin
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13 hours ago, ifibrin said:

New old stock ETA 2641 movement,

as it was a new old stock movement did you put it on the timing machine before you service?

13 hours ago, ifibrin said:

This was because they didn’t carry any new sealed mainspring for the 2641, and only had a new unused complete barrel assembly from a donor movement.

then why did you replace the mainspring barrel?

Then it appears to be your holding the watch in the timing machine in the movement holder why are you not holding the watch in the timing machines holder directly?

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7 hours ago, JohnR725 said:

as it was a new old stock movement did you put it on the timing machine before you service?

then why did you replace the mainspring barrel?

Then it appears to be your holding the watch in the timing machine in the movement holder why are you not holding the watch in the timing machines holder directly?

I didn't place the movement in the timing machine as I didn't have access to the timing machine when I was servicing it; I was working on the movement at my relatives' place.

 

The mainspring was replaced because the mainspring flew out with too much force as I was opening the barrel assembly, and appeared to have become distorted. I think I will open the barrel assembly in a small ziploc bag the next time. This is the first time I have opened any barrel assembly for servicing.

 

Are you supposed to place the watch movement directly in the timegrapher's jaws? I always thought you could use the timegrapher in the movement holder! I will try placing the movement in the timegrapher's jaws directly!

Edited by ifibrin
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32 minutes ago, ifibrin said:

My model of the timegrapher doesn't have the option for gain control.

Right. Try placing the mov.t holder differently on the mic. I do not recommend placing it directly on the mic, because it may pop off easily with great damage.

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3 minutes ago, jdm said:

Right. Try placing the mov.t holder differently on the mic. I do not recommend placing it directly on the mic, because it may pop off easily with great damage.

Interestingly, rotating the movement in different positions in the movement holder, or placing the movement holder in different orientations with respect to the jaws of the timegrapher, appears to have an effect on the amount of noise seen in the timegrapher trace. Unfortunately, the effect appears to be inconsistent, at least when I did it in the past, so I wasn't sure if the change in noise was due to having agitated the movement, or due to shifting the position.

Also, timing the movement directly while the movement is in the plastic shell the movement was shipped in also appears to increase the noise!

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2 hours ago, jdm said:

I do not recommend placing it directly on the mic, because it may pop off easily with great damage.

3 hours ago, ifibrin said:

Are you supposed to place the watch movement directly in the timegrapher's jaws?

yes you are supposed to place the watch directly in the timing machine microphone if you want the best pickup. fter all that split the microphone holder was designed for is designed to hold watches movements in particular. There is a minor problem for the Chinese isn't designed the best but still that's what it's designed for. Sometimes it doesn't matter who's movement holder Chinese are Swiss if you hold a complete watch that sometimes is problematic. Because the jaws are specifically designed to grab the edge of the movement the dial side in particular. A complete watch like a pocket watch for instance has rounded edges in the case and sometimes that doesn't work well. 

and no matter what you do want to be careful that it actually is in the microphone and not at some weird angle are on the edge or something else then it could pop out.

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7 hours ago, JohnR725 said:

After all that split the microphone holder was designed for is designed to hold watches movements in particular.

Maybe it has been designed for watchmakers liking to take risks. Most of us have Chinese machines and on these if you place the mov.t all the way down is actually too close to the mic, and if you put it on top of the jaws is will be hold very poorly, so if you go to regulate or just rotate it, you're gambling with physics.

I have a perfectly good signal with either the mov.t in the holder, or in the case, either with or without the caseback. Only occasionally I need to adjust gain for a diver's having a thick case, but that's not always not even for identical pieces.

Perhaps the OP can try placing the mov.t alone in the mic and report if that makes any difference in this case. 

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11 hours ago, ifibrin said:

My model of the timegrapher doesn't have the option for gain control.

Are you positively sure about this? On the Weishi 1900 we can simply push the up and down arrow buttons on the front right of the panel to increase or decrease the gain. I could be wrong, but I believe I read somewhere that the gain can be adjusted via the menu of the Weishi 1000. If you haven't looked into it, it could be worth it.

Anyway, if there's no way to adjust the gain, place the movement directly on the microphone stand. I've done it many times without any problems whatsoever. However, be a bit careful if you try to manipulate the regulator arm while on the stand, and make sure the gripping parts are perfectly clean. Use cotton swabs soaked in IPA, and then blow it dry of IPA and any cotton fibers.

Edited by VWatchie
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4 hours ago, VWatchie said:

Are you positively sure about this? On the Weishi 1900 we can simply push the up and down arrow buttons on the front right of the panel to increase or decrease the gain. I could be wrong, but I believe I read somewhere that the gain can be adjusted via the menu of the Weishi 1000. If you haven't looked into it, it could be worth it.

If you push the up down keys on the 1000 machine the only thing you change is the contrast of the display. It does not have any way to adjust the gain.

If you look at the display of the 1900 the top right it displays the beats per hour the machine is set to. Alternating with the gain adjustment. No such display appears on the 1000.

Another reason why the 1900 is a much better purchase than the 1000 is not just a pretty color display that makes it different. On the other hand having any timing machine in the hand of anyone working on a watch is better than no timing machine like we used to have when people are trying to diagnose their watch looking at a crystal ball or whatever they were using. Or worse than a crystal ball using a phone app.

8 hours ago, jdm said:

Maybe it has been designed for watchmakers liking to take risks. Most of us have Chinese machines and on these if you place the mov.t all the way down is actually too close to the mic, and if you put it on top of the jaws is will be hold very poorly, so if you go to regulate or just rotate it, you're gambling with physics.

To understand the problem of the microphone I'm attaching a picture. The Chinese didn't quite Clone the microphone correctly. Just a little additional machining on the outer jaws and the problem would've been solved but they didn't.  Which is unfortunately bad because This is how you're supposed to hold the watch if you want the best signal quality.

16 hours ago, ifibrin said:

Also, timing the movement directly while the movement is in the plastic shell the movement was shipped in also appears to increase the noise!

Not so much noise just not getting a good signal. This is also a common problem with some watches in their chase if the casing material insulates the movement from the outside world you have inconsistent results. In other words big heavy cases tend to be bad cases with plastic movement rings Also can be a problem. Then it doesn't matter whether this is a Chinese machine or Swiss machine some Watches in their case are just hard to pick up. It's also important that the crown face outs as that cans to help get a better signal but not always.

9 hours ago, jdm said:

I have a perfectly good signal with either the mov.t in the holder,

Do you have a preferred way to hold the movement holder in the timing machine Pick up? If you look at the picture way up at the top he's holding the movement holder sideways is this the way that you hold the watch or do you have the knob of the holder facing out?

 

 

microphone cloned poorly.JPG

WeiShi Timegrapher 1900.PDF

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2 hours ago, JohnR725 said:

To understand the problem of the microphone I'm attaching a picture. The Chinese didn't quite Clone the microphone correctly.

So, obviously this has been improved, and would explain why I've never had any problems attaching my movements directly to the microphone on my Weishi 1900 which I bought, I believe, some three years ago. See the below picture.

1450004788_Weishi1900Microphonestand.jpg.ae813fc467e00d6ff85733e167e5892c.jpg

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1 hour ago, VWatchie said:

So, obviously this has been improved,

I noticed on eBay sometimes they'll sell the microphones separate and claim their new and improved but conveniently they never said what they improved. Yours definitely looks improved as that would hold the movement without it falling out.

 

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I find the gain function to be, if not crucial, at least extremely convenient, so I do recommend the Weishi 1900 over the Weishi 1000. I remember how I struggled with an Omega 268 giving poor results on my Weishi 1900 until I decreased the gain which resulted in the TM showing the correct and video verified truth.

Edited by VWatchie
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23 hours ago, HectorLooi said:

Just curious... did you lubricate the pallet jewels or the escape wheel teeth?

I did oil the pallet jewels with escapement lubrication. Interestingly the default lock is so much that in the absence of this lubrication, the watch doesn’t run at all.

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19 minutes ago, ifibrin said:

Interestingly the default lock is so much that in the absence of this lubrication, the watch doesn’t run at all.

That is strange, and if confirmed, unacceptable. No parts in a watch should rely on presence of lubrication to move or slide in relation to each other.

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6 minutes ago, jdm said:

That is strange, and if confirmed, unacceptable. No parts in a watch should rely on presence of lubrication to move or slide in relation to each other.

I don’t have the tools to adjust the pallets, so I will just leave it as it is until I gain more experience. The more troubling part was the train bridge fouling the ratchet wheel in a NOS movement!

Edited by ifibrin
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7 minutes ago, ifibrin said:

Ok. The noise seems to have disappeared in all positions except crown down.

First picture shows insufficient amplitude. Second one has barely enough. But I don't think that is related to the problem in subject. Can you record the sound, 10 seconds will be enough, and place it on some sharing location. That will allow other to listen to it, and even look using a waverform application, looking for spurious noises. Of course, you're encouraged to do the same.

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I just found out that the silver metal piece IS the microphone/ vibration sensor. I had thought that there was a microphone inside the black tube, but some research has revealed that the silver metal piece is directly wired to the circuit in the black tube assembly!

I guess that makes sense why you should put the movement directly against the silver metal holder!

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18 minutes ago, ifibrin said:

I guess that makes sense why you should put the movement directly against the silver metal holder!

Don't assume that closer is necessarily better. There are situations in which a minor noise gets amplified too much and fools the software in detecting it instead to the actual impulse, that is why gain control is present on the other models. The machine is designed to work well even not only with the bare mov.t sitting 2cm far from the microphone with the metallic mov.t holder transmitting sound as a vibration, but as well  with it in a closed case and other noises in the room.

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