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Other Vintage Household Electrical or Electromechanical Items For discussions about other vintage (over 25 years old) electrical and electromechanical household items. See the sticky thread for details. |
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10th Jun 2016, 2:05 pm | #1 |
Rest in Peace
Join Date: Apr 2011
Location: Matlock, Derbyshire, UK.
Posts: 1,378
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Westclox direction
I have a Westclox clock in the kitchen which uses a synchronus motor. The motor can run in both directions and may need to be switched on more than once till the direction is correct.
The power went off recently for a second or so and I found that I had to restart the clock eight times before the direction was correct. Why is there a bias in the direction? Should I try the lottery? |
10th Jun 2016, 2:36 pm | #2 |
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Re: Westclox direction
It's sheer luck, the brain remembers co-incidental things more than the usual.
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10th Jun 2016, 3:34 pm | #3 |
Nonode
Join Date: Nov 2015
Location: Welwyn Garden City, Hertfordshire, UK.
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Re: Westclox direction
Many clock motors included a pawl that worked like a ratchet.
If the motor started in the wrong direction the pawl would stall it. Usually the rotor would bounce and start running in the opposite (correct) direction. Maybe the pawl is stuck or broken - that is if it ever had one? |
10th Jun 2016, 5:04 pm | #4 |
Dekatron
Join Date: Jan 2012
Location: Brentwood, Essex, UK.
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Re: Westclox direction
I used to have a 1960's Westclox where you had to manually turn a knob in the direction shown by an arrow to get it started: it normally wouldn't start otherwise. My 1940's Westcloxes have the pawl and spring mechanism that do it automatically
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10th Jun 2016, 6:23 pm | #5 |
Dekatron
Join Date: Jun 2009
Location: Staffordshire Moorlands, UK.
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Re: Westclox direction
I have an old factory clock that does that sometimes. It shouldn't; it just has a worn ratchet. If you turn it by hand with the power off you can feel the ratchet work but straight on the mains sometimes catches it unawares or the second hand sometimes does nearly one revolution before getting it right.
It can be a problem with mirrorballs (!) too as they rarely have a directional motor; the problem being that if they turn backwards they can unscrew themselves if they're poorly assembled.
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10th Jun 2016, 8:35 pm | #6 |
Dekatron
Join Date: Feb 2007
Location: Leominster, Herefordshire, UK.
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Re: Westclox direction
That sounds like a novel way to end up seeing stars
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11th Jun 2016, 1:43 am | #7 |
Dekatron
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Location: Lincolnshire, UK.
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Re: Westclox direction
I remember when the old gas central heating boiler clock used to do this. It dated from 1967 and had this brass electric clock inside a metal case with a round front cover that you pulled off to set it. There were many more power cuts out in the villages in those days than there are now so the boiler clock going backwards was a regular and very annoying thing. I remember my mother switching the electric supply off and on again to hopefully get the clock to run in the right direction. The problem was that due to the nature of the clock, you couldn't actually see it moving, so you wouldn't know which way it was running for probably a half to one hour. It could be several hours worth of switching if you were unlucky, to get the clock to hit the right half cycle of the mains to kick it in the right direction. Knowing what I know now I could probably have fixed it, but it was due to this clock fault that this otherwise reliable cast iron lump was eventually replaced.
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11th Jun 2016, 8:50 am | #8 |
Dekatron
Join Date: May 2008
Location: Derby, UK.
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Re: Westclox direction
Does turning the time setting knob get the hands going the right way?
I'm sure I remember an old electric clock that worked this way -- advancing or retarding the time left the clock running in the same direction as the last adjustment was made. I guess the idea was, if the power had been interrupted, then the clock would have lost time; provided you advanced it at switch-on, that would force the motor to spin in the correct direction. It was too long ago to be sure whether that clock was a Westclox, though. What if you fitted a 1N4007 diode in series with the motor, with a push-to-break switch in parallel with the diode? Depressing the switch would pull the armature to a known position and hold it there, and releasing it would apply a half-cycle of the opposite polarity (either straight away, or after another half-cycle of the same polarity which would not cause it to move). Reverse the diode if the clock starts consistently the wrong way, of course. (I'm not actually sure if that would even work. But as a quick experiment with parts you probably already have in a drawer, it could be worth a shot.)
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12th Jun 2016, 3:52 pm | #9 |
Dekatron
Join Date: Feb 2007
Location: Leominster, Herefordshire, UK.
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Re: Westclox direction
Not sure it would do anything different after being parked like that. The problem with single phase motors is that when they're not rotating, the field simply pulses in opposite directions with no rotating force. It might even just sit there humming gently to itself.
Of course just a few cycles of dc might even burn out the winding!
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12th Jun 2016, 5:11 pm | #10 |
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Re: Westclox direction
Self starting clocks do have a ratchet (mentioned earlier, it may not work though) to get them going the right way, I prefer non self starting, then you know how long the power cut was for. Mind you I can't remember having a power cut here in the last 20 odd years.
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