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  1. #1

    Default ITR master clock, contacts worn.

    I am currently restoring an ITR master clock movement for a college, and have run into a snag- the thin brass strip that covers the bar on which the solenoid acts is worn out, as shown in the picture. It is very thin, about 0.1 mm thick. Is this just standard brass sheet that I can buy from M.S.C., or are parts like this available ready-to-go from a supplier?

    I have restored several of these in the past, and even owned a couple, but have never seen this sort of damage before. Thanks.



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  2. #2

    Default Re: ITR master clock, contacts worn.

    Another question. The college would like me to bypass the transformer on the clock case, since it is festooned with worn out cloth covered wire. In the past I have purchased a simple power supply to power these- is there a particular power supply that folks have settled on and been happy with to operate these? In the past I've used one purchased from Radio Shack. Both magnets on this movement are marked 12 volt.
    Last edited by Peter A. Nunes; 04-26-2017 at 11:20 PM.
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  3. #3

    Default Re: ITR master clock, contacts worn. (By: Peter A. Nunes)

    i remember reading something on kensclockclinic.com about how he restored contacts... it was above my pay grade so i just sent my stromberg master clock movement to him to restore, and he did a great job. you might reach out to him (unless he's already online here?)
    i collect antique clocks because i get all that extra time...

  4. #4

    Default Re: ITR master clock, contacts worn.

    Quote Originally Posted by smike View Post
    i remember reading something on kensclockclinic.com about how he restored contacts... it was above my pay grade so i just sent my stromberg master clock movement to him to restore, and he did a great job. you might reach out to him (unless he's already online here?)

    Thanks, these aren't really contacts, which are above my pay grade too. I should be able to fabricate a new piece with thin brass, maybe shim stock from McMaster-Carr. I'll add a picture once I get it figured out and finished. Thanks.
    Last edited by Peter A. Nunes; 04-27-2017 at 08:08 PM.
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  5. #5

    Default Re: ITR master clock, contacts worn. (By: Peter A. Nunes)

    If any one needs .004 brass shim stock, I am now the proud owner of a roll 6" wide x 100" long, from M.S.C.
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  6. #6
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    Default Re: ITR master clock, contacts worn. (By: Peter A. Nunes)

    I've been using switching power supplies made by Mean Well. They come in various voltages. I purchase them on Ebay. The nice thing is that they are adjustable and they are small only 3 1/2"x2"x1". Have been using several for the last 3 years. Hope this helps

  7. #7

    Default Re: ITR master clock, contacts worn.

    Quote Originally Posted by Scot Traffis View Post
    I've been using switching power supplies made by Mean Well. They come in various voltages. I purchase them on Ebay. The nice thing is that they are adjustable and they are small only 3 1/2"x2"x1". Have been using several for the last 3 years. Hope this helps
    Thank you very much. They are rated in volts, as well as amps. Which amp rating have you been using?
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  8. #8

    Default Re: ITR master clock, contacts worn. (By: Peter A. Nunes)

    Here is a photo of the coils. They are each marked 12 volt, and they are in series, so I apparently need a 24 volt power supply (thank you Harold).



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  9. #9

    Default Re: ITR master clock, contacts worn.

    Does anyone have an extra dial mounting screw? One is missing, and I'd love to get one that matches the others. It is a 4/40 screw with a large head, aluminum I think.

    Here is a picture of the finished movement, running well on the manually wound spring only. These are very well made movements, and this one only needed one bushing. The pivots received a good burnishing, but none were scored.

    The cast iron mounting bracket makes a good test stand.

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  10. #10

    Default Re: ITR master clock, contacts worn. (By: Peter A. Nunes)

    I think you should try running this on 12 volts as the coils are marked. Using 24 volts may be the reason the brass piece was destroyed.
    I have restored several different makes of these type clocks and all of them seem to run OK using whatever voltage the coils are marked.
    For most of these I have had good results using a power supply or transformer with 1-2 amps output and the appropriate voltage.

  11. #11
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    Default Re: ITR master clock, contacts worn. (By: jkfabulos)

    The supplies I've been using are 0.7amps. That's enough for winding the clock. I agree that I would stick with a supply the same voltage as the coils are marked.

  12. #12

    Default Re: ITR master clock, contacts worn. (By: Scot Traffis)

    A few pictures of the new brass contact, or whatever it should be called. My trusty punch, a sharp screwdriver for scribing, and a pair of sharp scissors.



    - - - Updated - - -

    Quote Originally Posted by Scot Traffis View Post
    The supplies I've been using are 0.7amps. That's enough for winding the clock. I agree that I would stick with a supply the same voltage as the coils are marked.

    Hmmm- okay, I'll try that.

    - - - Updated - - -

    Quote Originally Posted by jkfabulos View Post
    I think you should try running this on 12 volts as the coils are marked. Using 24 volts may be the reason the brass piece was destroyed.
    I have restored several different makes of these type clocks and all of them seem to run OK using whatever voltage the coils are marked.
    For most of these I have had good results using a power supply or transformer with 1-2 amps output and the appropriate voltage.
    Thanks.
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  13. #13
    Forums Administrator harold bain's Avatar
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    Default Re: ITR master clock, contacts worn.

    When you have two 12 volt coils in series, it will always add up to 24 volts. Of course, I missed most of the "new math", so perhaps this has changed over the years.
    24 volts DC was the most common voltage used from the factory, unless there was a very good reason to use a different voltage.
    The wear on that piece of brass just indicates that the coils/ratchet wheel wasn't properly adjusted, as it shouldn't pull in far enough to be hitting the brass piece.
    harold bain, Member ch 33
    "If it won't "tick",
    let me "tock" to it"

  14. #14
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    Default Re: ITR master clock, contacts worn. (By: harold bain)

    just checked my international master clocks and the coils are marked just as pictured. My clocks are all 24 volt and have been running fine for years.

  15. #15

    Default Re: ITR master clock, contacts worn. (By: harold bain)

    Right, that is indeed the cause of the wear. That bar is easily adjustable, and I have it set so that the face of it is parallel to the faces of the two electromagnets. Once I get it clunking I'll have a closer look and adjust as necessary.

    - - - Updated - - -

    Quote Originally Posted by Scot Traffis View Post
    just checked my international master clocks and the coils are marked just as pictured. My clocks are all 24 volt and have been running fine for years.

    Thanks, Scot. The power supply I ordered is 24 volts, so I'll try that first to see how it goes.
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