Has my timing machine lost it's mind?

Discussion in 'Watch Repair' started by topspy, Oct 21, 2016.

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  1. topspy

    topspy Registered User
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    I have one of those cheap Chinese Weishi 1000 timegrapher machines. I've been reasonably happy with it, although sometimes I wonder about it.

    Tonight I was working on a nice railroad grade 21j Illinois. After cleaning it and getting it back together it was running strong (320-340 amplitude) nice clean lines on the timing machine, and .1ms beat error. The watch did have some major positional errors though, so I took the balance out and removed the hairspring to poise, and also found the dial-side pivot was a bit worn, so I burnished it. When I put it all back I had a beat error of 1.6ms. I kept removing the balance and tweaking the hairspring collet trying to improve, but kept overshooting.

    So, I removed the pallet, and adjusted the hairspring so that the roller jewel was dead center between the banking pins, looking at the axis of through the pins to the balance center. When I put it back together the beat error was 5.6ms! (has now settled to 4.6, and not changing.) Hairspring collet is tight, roller is tight, roller jewel is tight, hairspring is in the center of the regulator pins.

    So, do I trust this timing machine? Has anyone else seen this? Or is the beat really that far off?
     
  2. Skutt50

    Skutt50 Registered User

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    I think you can trust your timing machine this time. There is VERY little adjustment of the collet to get a rather high beat error. You could try to move the collet a tiny bit and see what happens.

    Another way of seeing how little is needed is to adjust a "modern" wrist watch of the type where you can change both the adjustment arm and the hairspring attatchment point in the balance cock, without removing the balance.
     
  3. karlmansson

    karlmansson Registered User

    Apr 20, 2013
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    I have the same machine and I recognize this. It seems to go with 5.6 a lot of the time... It may be a true reading but mine does it sometimes even when there is a straight line. My guess so far has been that maybe the lines have gone all the way around, and form a straight line on the "other side" of each other, if you catch my drift. That the display is in fact showing a spectrum of 5.6ms.

    Last time this happened to be consistently though it turned out to be an enlarged hole in the balance and subsequently a poorly riveted staff. Roller was tight, hairspring was tight but the staff kept turning in the balance. Especially on high amplitudes.

    Best of luck!
    Karl
     
  4. praezis

    praezis Registered User

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    Karl,
    one "way around" is 33 to 40 ms @18000, depending on the machine, without extra enlargement. 5.6 ms is too short for your suspicion. It also must fit in 200 ms without fraction then.
    Frank
     
  5. karlmansson

    karlmansson Registered User

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    #5 karlmansson, Oct 22, 2016
    Last edited: Oct 22, 2016
    Then I really don't understand what is going on... Maybe there is some inconsistency in the escape wheel causing intermittent beat error in turn causing the machine to interpret it as a consistent error? A straight line a standard magnification should be a lot closer to 0 than 5.6, right?
     
  6. NC Plumber

    NC Plumber Registered User

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    Just because the roller jewel is dead center between the banking pins does not mean the watch is perfectly in beat, usually it does but not always. You'll need to look at the pallet jewels- escape teeth relationship to be sure.
     
  7. praezis

    praezis Registered User

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    #7 praezis, Oct 22, 2016
    Last edited: Oct 22, 2016
    Hi,
    below I will show one reason for a false measurement:

    A false escapement error value can appear, if one of both ticks has a too low 1st pulse:

    TM2f.gif
    TM assumes falsely 2nd pulse as start of tick noise.
    Also resulting in too high amplitude value.
    Red line is trigger treshold.

    TM1f.gif
    Other noise gives good evaluation.
    Result: false escapement error value

    TM2r.gif
    Lower Treshold gives correct start of both tick noises.
    Result: real escapement error and amplitude value.

    However to be sure if your TM display can be trusted, you need a scope screen.
    Else you have to trust it like a blind man.

    Frank
     
  8. karlmansson

    karlmansson Registered User

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    I meant that my timing machine showed a single, straight line (not two as one would expect for beat error) and still interpreted it as 5.6ms. It was also close to impossible to adjust it to 0. I used the method of determining direction of error by leaving the balance just at the verge of unlocking the escapement and seeing from which direction the balance would self-start. I've had the same issues in both watches with a fixed and moveable stud holders so I've hade plenty of opportunities to adjust both finely and coarsly, moving both stud and collet on different occasions. Same result on both.
     
  9. karlmansson

    karlmansson Registered User

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    Thanks Frank!

    My timing machine is a cheap Chinese one and does not have a scope function. I'm thinking I might be able to high jack the signal from my pickup into a standard XLR cable and that way be able to record the audio. The pickup has been my primary problem with that arrangement so far. Your example above may very well be the explanation for the readings. But it does not explain why my timing machine can show both a single, straight line AND a 5.6ms beat error...
     
  10. praezis

    praezis Registered User

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    Karl,
    I have no explanation for that, it should not be possible.
    My guess is a software error.
    Frank
     
  11. topspy

    topspy Registered User
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    #11 topspy, Oct 22, 2016
    Last edited: Oct 22, 2016
    My TM is showing two separate lines, not a single one as in Karl's case. I had this watch running with a .1ms beat error before, and other than removing the balance to poise and then the pallet to center the roller jewel, nothing has changed. So I doubt the escape wheel is the fault. I'll have it apart again today and will carefully check the pallet, and double check that the roller is still indeed centered.

    However I think Praezis is on to something here. I do have an oscilloscope in storage, I'll have to dig it out and see what the signal from the pickup looks like...... I wonder if these cheap Chinese TM's have an internal pot to adjust threshold?

    Praezis: I'd love to get the software you are using! Can you tell us what it is, where to get it? I've looked for it online and don't see anything quite like it..... Thanks!
     
  12. gmorse

    gmorse Registered User
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    Hi topspy,

    I use the Delph Electronics eTimer Windows software in its free demo form, which takes a recorded trace from any recording package, (I use Audacity). It's very comprehensive, has all the functionality you're likely to need, and displays a "paper trace" as well as the waveform if required. It also plays the actual recorded sound of the escapement, not just "pings". I have a piezo pickup running through a small amp into the audio input jack, but this isn't always needed for the louder pocket watches.

    Regards,

    Graham
     
  13. praezis

    praezis Registered User

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    Hi topspy,

    the author of this software TM is me. Initially it was written for use in my own workshop.
    I could not find anything in the web that could please me and I wanted all the features that a Swiss 6000+ SFr TM offers and more.

    The shown full version can be purchased and is in demand by professionals mainly, but in some German fora I postet a free (less features) version. I just finished an English translation and can post it here if wanted.

    Regards,
    Frank
     
  14. topspy

    topspy Registered User
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    Yes, Please do!
     
  15. karlmansson

    karlmansson Registered User

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    It would be greatly appreciated Frank! Does it feature real time analysis?
     
  16. topspy

    topspy Registered User
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    Interesting.... I placed the watch back on the TM a few minutes ago, and now it is showing exactly what Karl described - a single line with 5.6ms beat error.

    While waiting for Frank to respond I have downloaded the software that Graham suggested. The demo version won't let you do real-time analysis, you have to provide it with a prerecorded .WAV file. I have a small stereo amp with volume control, about 1 inch square. I've just ordered various connectors and a project box, and will assemble it so I can use the pickup from my TM to output to the computer. For anyone that has the same TM (the 1000) the connector is a 3-pin microphone connector, which took me a while to find.

    Anyway, I'll report back once I know more.
     
  17. topspy

    topspy Registered User
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    I removed the pallet again, and it looks fine. Here are two pictures of the roller jewel, the first from above, the second looking between the plates. As you can see the first one looks like the jewel is off a bit to the left, whereas the second pic looks more centered. Perhaps It's just a parallax error on my part. Still001.jpg Still002.jpg
     
  18. praezis

    praezis Registered User

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    Hi,

    I started a new thread here. Was a bit of work until I managed that!

    Frank
     
  19. RJSoftware

    RJSoftware Registered User

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    Did you remove much material when you poised it? (I'm not so good with poising as it reminds me of cutting the legs of a chair to get it to set even, seems to never be perfect for some reason).

    I wonder too if a spring can develop a favorite direction. Bending easier in one than the other. Overcoil...?
    RJ
     
  20. topspy

    topspy Registered User
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    No, just a tiny amount from the underside of one screw. It was pretty close.

    After about 27,000.000 attempts, I finally got it back to .2ms beat error. I think. I'm still wary of this timing machine. I've gotten both the software that Graham recommended and the free version from Praezis, and as soon as I get this interface/preamp box built I'm going to be doing some comparisons.
     
  21. bvanfossen

    bvanfossen Registered User

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    I'll be interested in your comparison as I need a timegrapher
     
  22. Skutt50

    Skutt50 Registered User

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    When I check the position I do it with the fork in place. No force on the main spring and the fork should end up in the middle of the banking pins........
    Trying to judge where the jewel is as you indicate in your pictures, to me seems very difficult.
     

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