ScrapHappy October 2021: Exorcising a Ghost in the Machine with a Light Bulb

What lies beneath this ancient plate that no one has looked inside for nearly a million, well 40, years?

What lies beneath this ancient plate that no one has looked inside for nearly a million, well 40, years?

A while ago, the Snail bought a 1970s’ vintage Bernina sewing machine, which is way too scary for me to use but that she drives without a care in the world, not knowing that it is clearly haunted by the ghost of a, well, suffice it to say, a ghost. The other morning, just as the sun was rising*, that ghost manifested itself.

The sewing machine just started sewing. On its own. No one around.

For one such as I, who is terrified of these electric sewing machines (or crazy-electron-using-thread-knotting hell-machines as I call them), it was only after more than the usual number of tots of rum for breakfast that I was told the awful truth: this is a known fault and it really is simple to fix.

Calling the issue a “fault” is unfair. Bernina machines are built to last forever, presumably so that when they inevitably acquire the machine equivalent of a soul at some point, they can take over the Universe. Anyway, brushing away the image of a walking foot being chancellor of the exchequer for a moment, there is a capacitor (I’ll explain in a bit) in the foot pedal controller thingy** which is manufactured such that it has a lifetime of around just 30 to 40 years. Imagine that! Imagine a mobile phone built to last more than a quarter of a century! Nope, me neither (<goes off for a quiet internal monologue-type rant>).

OK, what in blogging hell is a capacitor, I hear you cry (or is that my internal monologue too?). Well, it is a thing that stores electricity for a bit and then discharges it, so it effectively smooths out ripples in the water-like flow of electricity (if electricity flowed like water. Which it doesn’t.). Here, I think it just makes the speed of the motor smoother as you use the pedal. This type of capacitor uses a layer of paper and a layer of metal to produce the desired effect. After 40 years, the paper has broken down (much as I did when I was 40), so the two ends are essentially connected and the whole thing passes electricity all the time, irrespective of where the pedal is and whether there is actually a human operator present. This machine is a whisker away from ticking that box that says “I am not a robot” and getting away with it.

Fixing the capacitor is, in theory easy, provided you have the right replacement capacitor. Now, you can buy ones specifically for such pedals OR you can use a light bulb, obvs.

As I have ranted on about before explained before (here), modern energy efficient light bulbs (the compact fluorescent and LED kinds) have some electronics in to make them work. When the light-making bit stops making light, all the electronic components are destined to be, at best, melted down, at worst, left in landfill. Whether energy efficient bulbs (CFs or LEDs) are better overall for the environment is a whole other rant for another day. For this day, such a circuit board was recovered and a suitable capacitor – right capacitance value, size and voltage rating – was rescued from a melty/landfill future to live its life in the volume***, I mean, speed pedal of a sewing machine. I bet its what that capacitor grew up wanting to do.

After 40+ years of loyal service, this capacitor has gone all gooey on us

After 40+ years of loyal service, this capacitor has gone all gooey on us


473K400? But you don't look a day over 25...

473K400? But you don’t look a day over 25…

I assumed that it would take me ages to scavenge a new component, but a bit of an old CF bulb was lying on my workbench, actually on top of the junk, er, useful things that live there. And you know what? That brown sweet-looking thing marked 473K400 was perfect – being, as it is, a 0.047 microfarad 400 volt capacitor and not a piece of gone-off strawberry chewing gum. The original capacitor was also not a piece of gone-off strawberry chewing gum but was, in fact, a 0.05 microfarad 250 volt capacitor. Happy days, if you are a nerdy electronics geek like me.

New capacitor, ready for 30 years' service

New capacitor, ready for 30 years’ service

As you can see, the new capacitor is much smaller than the old one and rated at 400 volts rather than 250, which means it should be even better! Whether it will last longer, I wouldn’t like to say. Ask me in 30 years…

Help! There's a bee using the sewing machine!

Help! There’s a bee using the sewing machine!

oOo

* Apart from the implicit plagiarism of song lyrics, the sun did not so much rise as hide behind the rain the whole day.

** Sorry, being technical again.

*** Oops, I play electric guitar and am way more used to volume pedals.

 

 

Many other people contribute to Kate and Gun’s wonderful ScrapHappy every month – check out what they have been up to too!

KateGun, EvaSue, Lynn, Lynda,
Birthe, Turid, Susan, Cathy,  Tracy, Jill,
Claire, Jan, Moira, Sandra, Chris, Alys,
Claire, Jean, Jon, Dawn, Jule,
Gwen, Bekki, Sunny, Kjerstin, Sue L,
Vera, Nanette, Ann, Dawn 2, Bear,
Carol, Preeti, Edith, Debbierose and Esther

Categories: recycling, repair, ScrapHappy, Sustainable Stuff | Tags: , , , , | 28 Comments

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28 thoughts on “ScrapHappy October 2021: Exorcising a Ghost in the Machine with a Light Bulb

  1. This is a VERY superior bit of ScrapHappery! Do please continue to blind us with science, and I’m so happy the Bernina has being somewhat reined back from its quest for independent living/thought.
    All those bits ending in -tor are all very well, but they play merry hell with everyday life. My current bugbear is the actuator in our dryer, which is playing silly buggers and requires me to rotate the drum anti-clockwise by hand a couple of times before it condescends to start work. Cheaper and quicker than installing a new part, of course. Until it stops working altogether…. And of course, I’m unlikely to find the necessary bit lying about on my work bench. Unless it’s a pin or bit of fabric, of course.

    Liked by 2 people

  2. I LOVE THIS SCRAPHAPPY it’s made me feel 7 and super safe and secure. Thank you.

    Liked by 1 person

  3. When amazed me most was not that you had an appropriate capacitor hanging around and could mend it (I have complete confidence in you), but that I knew what was wrong (I have much less confidence in my understanding of things electrical).

    Liked by 1 person

  4. I had an ancient second hand Bernini once. Eventually it caught fire in spectacular self-combustion. You may have averted a catastrophe here.

    Liked by 1 person

  5. Going Batty in Wales

    I have an understanding with sewing machines but you lost me when you got to ‘capacitor’ and even your excellent explanation didn’t find me again. So I am very impressed! From now on I shall consult you whenever a nerdy electronics geek is required!

    Liked by 1 person

  6. Susan Nixon

    Oddly enough, I actually understood most of that! You did an amazing fix here, and I’m officially impressed with your ability to make stuff work – are you sure you aren’t a Star Trek engineer?

    Liked by 1 person

    • I’m not sure I would pass muster as a “Scotty”-type although I do have the technical manual for the Enterprise (1701D model) so I guess I could learn! 🙂

      Like

  7. well, I am impressed! I’ve been using an electric sewing machine for approx. 70 years (started young) and got along fine without ever knowing any of that. But now, if my machine starts to misbehave I’ll know what to tell the repairman. Don’t have a Bernina so maybe my machine will last as long as I do.

    Liked by 1 person

  8. Bear

    Oh, my dearest, thank you for the laughter. I have a machine with a “ghost” too, only it’s very new, and not Bernina. Suffice it to say, that in my case, it comes to life when Hubby transmits on certain frequencies on his HAM (Amateur) Radio. This was discovered while in the middle of sewing a Vintage Linen’s quilt… the durn machine took off on it’s own, ruining over half the quilt before I could stop it by pulling the plug from the wall. That was the first time… the machine now resides back in it’s carboard prison (aka box it came in).. need I say more???? I’ve blown a few capacitors in my time… loud, smokey, and sometimes with a dazzling display to boot. LOL! But never within my sewing machine. I asked for a non-electric Treadle style machine for Christmas…. we’ll see…

    Liked by 1 person

    • Well, I have never heard of a sewing machine being troubled by radio transmissions before – I thought the new ones ought to be immune. You’ll have to make it its own tin foil hat!
      I too have experienced the explosion of capacitors, some of them cover your circuit boards in weird, probably highly poisonous, fluffy gunk (which might also be a good name for a rock band)…

      Like

      • Bear

        heheh. The incident with the sewer puzzled and still puzzles us. My machine is right under the end of his antenna, though… so that might be a radioactive zone. It’s not happened since, but I don’t sew while he’s on the radio/SDR either.

        Like

  9. I guess the Bernina sewing machines will one day take over the world and there will be no more scraps, no more UFO:s and no more clothes with holes in them. What a day that will be 🙂

    Liked by 1 person

  10. claire93

    does this mean you’re a qualified exorcist now?

    Liked by 1 person

  11. Your capacity to amuse, and educate me never fails…now I wonder what that sparking and electric smell might be on my ancient (Singer) foot pedal…I wonder if I have a light bulb lying around, and if I can get my electronic-adept middle child to perform surgery on it?

    Liked by 1 person

    • Certainly worth taking the pedal apart to have a look! There seem to be a few videos on YouTube to help. Let me know if you do open it up and it needs a component, I’m sure I can send it to you! 🙂

      Liked by 1 person

  12. Well my issue yesterday was that suddenly the machine wouldn’t “speed through a stitching” – I had no idea what happened other than I had just decided to replace the needle. I got out the trusty manual which has oodles of diagrams and whilst I was thinking about what to do, I spied a little diagram of the “speed mechanism” – I looked at it on the front of the machine and it was set to just one of these > and there were more settings like >… >>… >>>. So I tried it at >>> on a scrap (not the actual piece) and it fired up. I must have accidentally moved the slider when I was sorting out the needle… (it;s not a bernina

    Liked by 1 person

    • So easily done – at least you didn’t end up taking the thing apart trying to fix something that was, in fact, OK as I have done before now. I spent a morning diagnosing a fault only to discover that one of the power supplies wasn’t on. Ain’t technology grand? 😂

      Like

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