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Christmas holiday plan: repair a 60s turntable

Jan Cumps

I have a turntable from the mid-60, Thorens TD 124. It has a mechanical issue: the speed selector has a worn-out component.

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This holiday I'll see if I can fix this. These tables, and the components, go for crazy prices (check ebay for anything related to a TD 124, it's a strange world out there).

The worn component is part of this contraption:

 

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  • Are you going to try a 3D print to replace the part?

  • Do you know specifically what's worn?  It seems like you are identifying a grub screw?  Is it just the belt?

  • in reply to Andrew J

    I do, and posted it. But it got lost in the forum issues. The belt  was fine, replaced in 2012. I'll post when the forum is stable.

  • in reply to DAB

    No. I am not into 3d printing. And this device is all aluminium, iron and even heavy cast iron. Plastic will not survive.

  • Some teardown pictures, and a (vertical!) stock taking video before the real work.

    I've taken the photos , so I can use them when rebuilding the table.

    Speed switcher on the left, part of the on/off switch arm.
    Through the hole, you can also spot part of the rubber idler wheel:

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    Removing the e-circlips and washer from the on/off arm:

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    Removing the washer and e-circlips from the speed switcher:

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    Check the sheet steel transmission belt:

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    ... and how it's mounted on the speed switch. If you look closely in the left bottom corner, you can see me removing the screw that fixes the belt to the switch wheel.

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    The switcher removed, and the separate parts taken apart. This is what needs fixing:

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  • The mechanism completely removed:

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    You can see the rubber idler on the underside (in reality the topside) very good in this photo.

  • It turns out that I'm lucky. The part isn't worn, but lost grip.

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    Symptom: the outer ring should turn the speed switcher, when it's turned by the plate steel belt. But it slips.

    Cause: the speed switcher is stuck - not 100% stuck, but the grease became sticky. Turning the switcher requires decent force. the setting screws gave up and lost grip. It was also hard to remove the contraption from the axle due to that stuck grease.

    Solution: remove the old grease. Clean the parts thoroughly. Regrease. Relevant parts only! Definitely not the part where the ring has to grip the switcher. Then put all back together and align.

    This sounds easy, but placing the belt back on (there is 0 flex in a plate belt) and aligning everything took me several hours.

    First video, of testing the fixed mechanism . The e-circlips have not been replaced yet:

    This is how it's supposed to work. Good news.

  • in reply to Jan Cumps

    Always good news when the fix turns out to be easier than expected.  We were having problems with the Bombe not so long ago with spurious stops and we investigated everything except what it turned out to be: a very slightly worn drive belt that was throwing the timing out by a smidgen (technical term!) - which is sort of why I mentioned the belt above.

  • in reply to Andrew J
    Andrew J said:
    We were having problems with the Bombe not so long ago

    This Bombe?