Microset as a diagnostic tool on a JUF/Schatz 400 day clock

Discussion in '400-Day & Atmos' started by chrisuk, Jun 12, 2019.

  1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.
  1. chrisuk

    chrisuk Registered User
    NAWCC Member

    Sep 4, 2010
    41
    5
    8
    Male
    Clock repairer & organist
    Staffordshire , UK
    Country Flag:
    Region Flag:
    #1 chrisuk, Jun 12, 2019
    Last edited: Jun 12, 2019
    A while ago I serviced a JUF/Schatz 400 day clock stamped 12 52 on the back plate, December 1952. I set up the Microset to use the optical sensor and connected it to my laptop.
    On_test(web).jpg
    Initial inspection of the escapement seemed ok but later I saw this trace on the laptop.
    trace-1.JPG
    Obviously something very wrong. Closer inspection of the escapement showed occasional mislocking, the pallet flicking back to the impulse face. I was surprised that this produced an easily detected disturbance to the pendulum. After adjusting the position of the fork and regulating the movement the trace looked like this.
    trace-2.JPG
    Job done.
     
  2. sjaffe

    sjaffe Registered User

    Dec 25, 2012
    417
    2
    18
    Engineer
    Santa Rosa,CA
    Country Flag:
    Region Flag:
    I'm surprised you could see this using the optical sensor. I would have expected if using the acoustic sensor. The first results look periodic, like there was a damaged tooth on the escape wheel. Quite a difference between the before and after graphs! I'm curious if the acoustic sensor would have picked up anything useful that the optical sensor missed.
     
  3. chrisuk

    chrisuk Registered User
    NAWCC Member

    Sep 4, 2010
    41
    5
    8
    Male
    Clock repairer & organist
    Staffordshire , UK
    Country Flag:
    Region Flag:
    Thanks for your interest. I generally use the optical sensor because there is too much background noise for the accoustic sensor to work well in my workshop, feet moving about, clocks chiming, me working on other jobs etc. The clock in question has a twenty tooth escape wheel and the Microset was reporting the rate at every 2nd event, ie each tooth. The actual log file covers more than 17 hours worth of data and overall there is no obvious periodicity in spite of the appearance of the sample shown.
    If I knew how to do it I would have attached the actual log files so that those of you with Microset software could down load them and examine them in any way you wished.
    A boxcar average with a sample size of 20 covering the data in the first trace looks like this.
    20-tooth-average.JPG
     

Share This Page