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praezis

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praezis last won the day on September 29

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About praezis

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    Germany

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  1. praezis

    D. I. Y. Watch Timing Machine.

    Hi, in my workshop I service mainly vintage chronographs. To adjust the beat error, I always have to rotate the collet. To see the pallet position and in which direction to rotate, I use to let down the mainspring, look, wind again. This means, after every check there is a different state of winding and amplitude. Beat error will show different [ms] values for the same error angle then, but beat error [deg] always shows the same value for the same error. That is why I like [deg] display for the beat error. Frank
  2. praezis

    D. I. Y. Watch Timing Machine.

    Hi Guido, here is your file running on PCTM. Amplitude varies 228...235 degrees. Frank
  3. praezis

    Sourcing a replacement mainspring

    Apart from the best reply of Khronos: exact length is least important. Frank
  4. praezis

    D. I. Y. Watch Timing Machine.

    Hi, yes, searching can be cumbersome. Microchip makes a few, e.g. mcp6002 or mcp6402. But their max allowed supply voltage is much lower than of lm358 . You will have to study the datasheets for details. Frank
  5. praezis

    D. I. Y. Watch Timing Machine.

    Guido, beware, the input resistance of that circuit (1 k) is too low for a piezo disc! With a bit electronic knowledge much can be adapted at this standard design. E.g. plug in a more modern OP replacing that grandfather of IC and it will work at 2V and lower. Frank
  6. When slotted balances are out of poise, you should also consider bent balance halves. Your slots look as if they are of different width. Frank
  7. praezis

    Help finding lathe collets

    The 40g is used in Germany. g for "Gang" means tpi. What is the diameter of the lathe bed, 25 mm? Frank
  8. praezis

    Tap and Die Kit

    Bergeon sold 4.7 mm punches with a set of collets. There are also collet holding arbors for Seitz jewelling tools, I have one in the big Seitz set. Frank
  9. praezis

    WOS mic & watch holder.

    Hi, rather late, I know. But just today I read this interesting thread again and looked at the sound file "Ingersol-trenton.wav" from post #1. From the speaker I could already hear considerable echo. Curious, I ran the file in PCTM (after conversion to mono). But there was a nearly perfect graph line and waveform, I could not see any evidence of suspected echo: Ok - filter is on by default. Switched filter off: Now the original sound appears. What a difference, the tic noise can hardly be recognized. Apparent is a wave at about 600 Hz, which probably comes from heavy resonance in the pickup device. And some 50Hz hum is visible, too. Frank
  10. praezis

    Mainspring for JLC

    Hi, first, my post was no reply to yours, just a few seconds later. Is this an antique watch? .. from 73 did not sound so. For comparing it is not wrong to have the sizes of the existing spring, but I would not use them for finding the new one. If calibre and references are not available, I use to take the sizes from the barrel and apply general rules to find width, legth and thickness of the spring. Frank
  11. praezis

    Mainspring for JLC

    Watchmakers normally don't measure the old spring, as it might be already wrong, but determine the movement calibre and look up the correct spring in tables. Frank
  12. praezis

    New Tool Question

    roller jewel
  13. praezis

    New Tool Question

    But who would remove a screw for filing the head? My best guess is holding a plateau jewel. Frank
  14. Attached a document to clarify my posts above. Frank CGS_INFOe.pdf
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