Sessions Clock Motor

Discussion in 'Electric Horology' started by rrryyyaaannn, Nov 17, 2019.

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  1. rrryyyaaannn

    rrryyyaaannn New Member

    Nov 17, 2019
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    Hi all,

    I have an old Sessions electric mantel clock whose motor suddenly stopped running. I thought it could be due to gunk buildup within the movement or the motor itself. At first, I removed the shaft/arbor from the bronze bearing and cleaned everything with a pipe cleaner and some WD40. Plugged it back in, and still no luck. Then I took the motor apart as far as I could, which involved opening the case to the point that I could see the copper wire, etc. There appeared to be a thin (plastic?) ring that seemed to act as a spacer for the copper plates that interface with the motor body. That spacer basically crumbled as soon as I popped the case open. I wasn't able to identify any broken wires or failed electrical components otherwise. After reassembling, the motor still shows no signs of life. No humming, no movement, no apparent magnetic force.

    What are my options for reviving this thing? I hate the thought of putting a $10 plastic replacement movement in it. I'm hoping I can track down a replacement motor, if this one truly can't be salvaged.

    A few pics are attached, showing the motor, and the clock body.

    IMG_2602.JPG IMG_2603.JPG IMG_2604.jpg IMG_2605.JPG
     
  2. kinsler33

    kinsler33 Registered User

    Aug 17, 2014
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    It's tragic from several standpoints, but your clock's motor, and thus its whole movement, are permanently deceased, doomed from the start because of less-than-optimal materials. The clock has, in effect, turned itself into an unreliable electrical appliance and thus a fire hazard. So, keeping the original dial and hands, prepare to destroy this fine old clock:

    You can order pure AC electric movements from Ronnell, who seem to have a good selection, e.g. Hansen Electric Rear Set Clock Movements - Synchron Type C (expensive)

    or adapt a much cheaper and equally-reliable battery-quartz movement, preferably of the silent continuous-sweep variety, which is all I'll use these days. You can adapt the existing hands with these:I-Shaft Conversion Washer 10-Pack and save a certain amount of trouble. Note that you'll have to deal with hand-setting and battery-holder considerations.

    Assume that it'll be a good deal of work to do a good job. There are millions of these nice old clocks around, and all have failed in approximately the same manner. There is no source for Sessions motors, and the one time I tried to re-wind one was sufficient to discourage me from a further attempt.

    Mark Kinsler
     
  3. wow

    wow Registered User
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    Jun 24, 2008
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    Ryan, welcome. I have a box of old motors. I will look through them and see if I have that one if you are interested.
    Will Walker
     
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  4. rrryyyaaannn

    rrryyyaaannn New Member

    Nov 17, 2019
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    kinsler33 : Thank you so much for your thorough (and authoritative) response! That's a shame, however, that there's no practical means to repair it, and no source for new parts.

    wow : I would certainly appreciate your taking a look through your motor stash! Please let me know if anything turns up.

    If not, I think I might still be up for an economical restoration a la quartz movement, if for no other reason than I hate to see nice things go to the landfill. :)
     
  5. kinsler33

    kinsler33 Registered User

    Aug 17, 2014
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    I hope that the replacement motor is available and works well. The insulating materials will have aged in the 'new' motor too, but won't have been subjected to fifty years of heat from the coil.

    You'll have to use your creativity when adapting a quartz movement, too. I should also have noted that Ronnell and the others have very small quartz movements that can slip into place with little alteration to the clock at large.

    But please be careful: the same heat that fried the motor was also present in the dial and hands. Many fine electric clocks had paper or plastic dials, or metal dials painted with paint that was not particularly heat-proof. Thus a dial, or even the finish on a set of hands, can crumble at the first touch.

    Mark Kinsler
     
  6. wow

    wow Registered User
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    I’ll look tomorrow morning. Sorry. Been a very busy day. Just read your response.
    Will
     
  7. Dan_in_WA

    Dan_in_WA Registered User

    Dec 21, 2019
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    Do you still have the junk clock motor?

    I have a similar Sessions clock motor with what I suspect to be a bad bushing. There is a small knocking noise while it runs.

    I’d like to acquire yours if I may, to make sure I know how to disassemble mine the rest of the way.

    I pulled the worm gear off of mine and removed the shaft, it looks like maybe a small spanner wrench could be used to remove the bushing(s) but I don’t want to destroy it if I’m wrong.

    If anyone else knows how to take these apart for bushing replacement, I’d appreciate it!

    Thanks, Dan
     
  8. Kevin W.

    Kevin W. Registered User
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  9. Dan_in_WA

    Dan_in_WA Registered User

    Dec 21, 2019
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    Hi Kevin, thanks for the quick reply!

    Is it known if the threads are right-handed?

    Also, the motor shaft on mine measured 0.068” dia. taking the measurements at several places.

    If I replace the bushings, should I ream them to 0.068” or 0.0685” ?

    I’ve rewound motors and changed bearings
    before, but nothing ever this small.

    Thank you,
    Dan
     
  10. rrryyyaaannn

    rrryyyaaannn New Member

    Nov 17, 2019
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    I too thought a small spanner wrench would be required, but it turns out the parts were simply pressed together.

    I just stepped into my shop and took a few pics of the disassembled motor that may help you.

    You can see the central post of the motor, through which the arbor passes, and has 6 notches which appear to be an interface for a spanner wrench, is not threaded at all. (Ignore the two prominent notches that I carved into the aforementioned post—that’s some desperation-related damage that happened in a brief fit of rage.) ;)

    Let me know if this helps.

    294AC0BB-3CDB-4B76-B661-3AFB5A2C3758.jpeg C247A96A-598D-4697-9E9F-23D0B2F06F30.jpeg 2977FF51-671D-44A3-8FD1-8DAA93AC99B1.jpeg
     
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  11. Dan_in_WA

    Dan_in_WA Registered User

    Dec 21, 2019
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    It looks like the bushings can be replaced without disturbing the coil or stator.

    Has anyone ever pressed these out? It looks like there may be 2 of them, a front and a rear with a gap between them that may hold felt with a light lubricant (originally).

    Any advice before I try extracting them?

    Thanks, Dan
     

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