Interpreting wavy line in timegrapher app?

[ZedsWatch]

I have a wavy line in my app Watch accuracy meter. I am a newbie, assume it should be a straight line, or as straight as possible.

The reading is taken on a chinese copy of a 7750.

Any suggestions to track down the problem would be welcome.

The following has been removed: The calendar module, automatic bridge and chrono bridge, central seconds wheel and minute wheel, cannon pinions.

The guard pin on the pallet fork is centered in the horn.

Both pallet jewels have the same engagement to the escape wheel. Is it possible the engagement is too much?

I've rotated the train of wheels and can't detect any runout of the wheels under a 10x loupe.

Could the roller jewel have a bad fit in the horn?

[Nucejoe]

What makes you think your watch has an issue?      Streight line this is.   Good luck regulating it so fine to take this 12 seconds/ day out.  If you did , apply for a job at COSC. 

 

[ZedsWatch]

I interpret the wavy line as the balance oscillations not being constant and therefore bad, am I wrong? 

I have seen other timegrapher results with straight lines, so i assumed mine was not proper.

I am happy to know my mistakes, if you can be specific, I would appreciate it. 

[tomh207]

The apps are not as reliable as a Chinese timegrapher and would be considered a lower tier. This is because of using a phone/tablet/computer microphone. 
 

Tom

[JohnR725]

16 hours ago, Nucejoe said:

What makes you think your watch has an issue?   

 

21 minutes ago, tomh207 said:

The apps are not as reliable as a Chinese timegrapher and would be considered a lower tier. This is because of using a phone/tablet/computer microphone.

One of the frustrations that we have on watch repair discussion groups is troubleshooting by apps. They look quite promising but as long as they're making use of the microphone in the device which was never designed for this that is a problem. So if you start trying to diagnose from an It will just lead to frustration because there's probably nothing wrong with the watch.

We've had more than one discussion where is finally concluded it was the app that was the problem not the watch. So other than a general idea in the best to buy the Chinese 1000 or 1900 timing machine excellent machines super for the money and will give you much better results..

Oh I don't suppose you have a demagnetizer? That's the first step before you put your watch on your timing whatever is to make sure it's not magnetized.

[Nucejoe]

JohnR and Tom advices are sound.

This app doesn't show amplitude which if low, the read out of chinese tg mentioned above can't be regarded valid. 

 

4 hours ago, ZedsWatch said:

I interpret the wavy line as the balance oscillations not being constant and therefore bad, am I wrong? 

You are right.

 

[ZedsWatch]

Thanks all, in addition to the condition described in my question, I did demag it.

I accept that the app and smartphone is not as accurate as the purpose built machines, and results can't be taken as being precise. But I assumed the wavy line could be taken as being an indication of a problem with the watch that I could diagnose. But this app did use the microphone on the phone. Another app that uses an external headset mic didn't show the wavy line.  So I should use the apps for even less than I am now. Got it.

Not having an amplitude reading is a problem.

I think I saw the side shake ( and end shake a little bit) of the pallet fork affect the division of the pallet stones to the escape wheel. I think the pallet fork tilts too much. So I will look into that.

[JohnR725]

50 minutes ago, ZedsWatch said:

the pallet fork tilts too much

Pallet forks are tricky things. When you new to watch repair and well basically all of us putting in a pallet fork can be a pain.

Somewhere recently on the group somebody was having an issue with the balance wheel engaging the pallet fork. Pallet forks seem to work but tilting wasn't quite the right word but they definitely were missing a pivot. So pallet forks have to stay streets in parallel and they actually have to have both of their pivots attached. Otherwise that would be a definite problem.

I'm attaching a something that will help you to interpret your timing machine graphical display. But a warning even though you get a nifty chart to certain degree reading timing machine graphical displays is similar to reading a crystal ball or tea leaves or whatever it's subject to interpretation. It should be an exact science but it may or may not be. For instance these are mechanical watches in the timing machine is more perfect than the watch. If the watches older things could be a little bit worn you may have just normal issues and if you think you're going to get this to look like a Rolex watch well that's going to be a challenge for. So not saying it should look like crap and you just ignore it but you have to be careful what you're interpreting and what you're going to do with that knowledge. But still the charts will point you in directions

Timing-Machine-Charts.PDF

[ZedsWatch]

Thanks JohnR, when I buy my timegrapher this will come in handy.

I made a point of ensuring the pallet pivots were in place. Still the side shake allowed the pallets to rock a bit ( using my smallest oiler as a push stick next to the pallet stones)

The pallets would range from centered on the escape teeth at one extreme to having the bottom edges of stones and teeth aligned at the other extreme ( due to rocking, not end play).

 

But again without a reliable graph I can't ascribe any error to this variation in division. 

 

[Nucejoe]

6 hours ago, ZedsWatch said:

the side shake allowed the pallets to rock a bit .

The pallets would range from centered on the escape teeth at one extreme to having the bottom edges of stones and teeth aligned at the other extreme ( due to rocking, not end play).

So, this fault needs to be fixed, some suggestion, 

Check if pallet arbour is securely attched to the fork.

and hole jewels for fork pivots might be  broken or  wrong jewel fitted or hte jewel itself is loose in the maniplate/ fork cock.

Loose fork cock and check its locating pins.

Good luck.

 

[p2n]

One other thing to remember is any app running on an android phone will be using Java and may not be able to make precice timings. (Not sure about iphone API's) That could account for some of the wobble. Have you used the app on a 'perfect' watch?