Help Would anyone like to have a go at fixing a Karlsson Flip Clock ?

Discussion in 'computers, web and general tech' started by urbanspaceman, Oct 28, 2018.

  1. urbanspaceman

    urbanspaceman Well-Known Member

    IMG_0027.jpg IMG_0029.jpg big-flip-white-cased-calender-wall-clock-43cm-2a2.jpg

    I wonder if anybody would like to have a go at fixing my Karlsson Big Flip clock. I live in central Brixton, and would be happy to pay for a successful repair. I just did some fault-finding.

    The calendar mechanism (powered by two D-batteries) works fine - if I rotate the weekday thumb wheel, that activates the day and month mechanisms correctly, and but it seems that the trigger from the analogue clock that activates the day-date mechanism is not working. In the photos you can see the three connecting trigger wires, ending in a white plug, disconnected here for cleaning (and later reconnected), to no avail.

    This task may suit someone who is an electrical/electronics hobbyist. If it doesn't work out, so be it. This is a last attempt before junking it.
     
  2. colacubes

    colacubes Well-Known Member

    Sounds like something someone at South London makerspace might be able to help with. Crispy might know someone.
     
    urbanspaceman likes this.
  3. gentlegreen

    gentlegreen sproutarian

    There is apparently quite a community around these clocks :-



    I'm definitely going to be using super glue and baking soda - I first saw it used to make fake ivory - repairing guitar frets.

    Forums - Flip Clock Fans Forum
     
    Last edited: Oct 28, 2018
    urbanspaceman likes this.
  4. Crispy

    Crispy The following psytrance is baṉned: All

    Yeah for sure. Actually we have a guy who made his own flip displays from scratch!
    EDIT: Loads of info here - Split-Flap Display — Tom Lynch

    I've posted up a copy of your op, urbanspaceman and will let you know if anyone bites :)
     
    Last edited: Oct 28, 2018
  5. gentlegreen

    gentlegreen sproutarian

    Worst case, if the clock contacts can't be fixed, all you need is one pulse every 24 hours which should be cheap and easy to make.
     
  6. urbanspaceman

    urbanspaceman Well-Known Member

    Actaully, I think it's one pulse every 12 hours, to energise the AM/PM flag.
     
    gentlegreen likes this.
  7. urbanspaceman

    urbanspaceman Well-Known Member

    Thanks for that. I look forward to any developments
     
  8. Jesito

    Jesito New Member

    Have you been able to fix it?
    It happens to happen I recently got one of those with the same problem (and a few more). Disassembling was not dificult. I was thinking on a contact failure at the analog clock side, so I took out the clock handles and carefully removed the thin clock face background (i'ts fixed with double side adhesive tape). The contacts lay below it, and in my case were fine. 15436540076871777585348.jpg
    I noticed some wobling at the connector side, so I resoldered the three spots on the left of the picture.
    No luck at all!. Still failing. As you can see on the picture, it is a simple mechanism. As the clock turns, it does first an electrical bridge between the bottom pcb track and the middle one, and later on between the middle and the top track. And after resoldering, this goes properly out to the contacts.
    15436546134652037289002.jpg
    So the problem lays on the other side.
    Now that we know how this mechanism work, we can mimic it on the cable, first shorting the middle contact with the bottom, then with the top. I uused my pliers for this. 1543654926557314872321.jpg
    But nothing happened. I followed the wires until the day-of-week engine:
    15436550397061219779752.jpg
    (Blue, orange and yellow wires, The red and white ones carry the power from the battery). I checked with the multimeter that red and white had power, and they had. So I slightly moved the other wires, trying to avoid contacts among them. And suddrnly the thing began working. So I resoldered the wires and put a tiny piece of isolation tape between them.
    Now it's working, but I face a second problem, the axis of the wheel that moves the digits seems to be broken, the wheel turns freely and the digits cannot be set from outside. A serious problem, this clock is just electromechanical, no inteligence at all, so every month that does not have 31 days the digits have to be set manually...
    I would have to either disassemble the mechamism or thinking of adding a microcontroller that control it straight from the contacts. Or maybe a simpler approach: three buttons outside the frame that close each of the three circuits when pushed in...
    Not so daunting once opened :) Good luck if you try it!

    15436559470464576400.jpg
     
  9. gentlegreen

    gentlegreen sproutarian

    Presumably, manually setting the date would be relatively painless ?

    Sounds like you might want to secrete an Arduino in there somewhere ... :hmm:
    You could add radio clock syncronisation ... :hmm: :hmm:
     
    Jesito likes this.
  10. Jesito

    Jesito New Member

    Well, this is an electromechanical clock, prone to failures due to the low quality of the assembly. Instead of relying on mechanical contacts I was thinking of using an Arduino (or alike, i.e. ESP8266) to drive the flip engines, just for the sake of reliability and to manually avoid updating the calendar every non 31-day month.
    And you are right, with an ESP8266 NodeMCU the time could be synchronized through the wifi...
    Currently all the modules have three wires going out and three more coming in. The analog clock sends two pulses (AM and PM) every 12 hours to the Day-of-week module, who sends one pulse to the day-number module every 24 hours, who sends one pulse every 31 days to the month-name module. This is a long serial chain. With a microcontroller the pulses would be sent to each of the modules independently thus increasing a lot the reliability, only one wire would be necessary from the microcontroller to each of the modules.
     
    mauvais, gentlegreen and editor like this.

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