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General Vintage Technology Discussions For general discussions about vintage radio and other vintage electronics etc. |
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17th Feb 2005, 3:23 pm | #1 |
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Noisy electric clock
I have a nice old Magneta electric clock in my kitchen. It's just over a foot in diameter and generally works well. It has 2 minor problems. The first one is that after turning it off, it often starts going backwards. Hardly a problem since it's on all the time and the power is pretty reliable in north London. Just try again until it goes the right way.
The real problem is that it makes odd noises. Difficult to describe, a cross between grumbling and buzzing. Not all the time. Sometimes it seems quite loud, other times almost silent. It's never loud enough to be very noticeable except when I'm sitting there quietly when it can be quite annoying. Any ideas from the horologists in the forum? (Not sure if this should be here or in the "Everything else" section, but I feel it falls into the "General vintage etc" class) |
17th Feb 2005, 3:37 pm | #2 |
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Re: Noisy electric clock
I have an early 50s Smiths electric chiming mantel clock. It started to become mechanically noisy a few years ago. I had a look inside and couldnt see anything that looked particularly delicate (just some reduction gearing) so I gave it a good squirt with WD40. It's been fine ever since
The running backwards thing just depends on which direction the motor decides to rotate. My Smiths always gets it right but I have a slightly earlier clock with a manual starter wheel on the back. On connecting it to the power you have to spin the wheel to start the clock. If you spin the wheel the wrong way, the clock runs (perfectly happily) backwards. Best regards, Paul |
17th Feb 2005, 3:49 pm | #3 |
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Re: Noisy electric clock
It's some time since I looked inside an electric clock with a synchronous motor despite having an early interest in these devices. I seem to remember the one I had, had a ring on the back of the motor with a pin mounted on it. If the motor went the right way, nothing happened but if the motor started the wrong way, then the pin would 'catch' on something and this would stall the motor for a fraction of a second and it would then commence to spin in the right direction.
I would think that the buzzing is either hardened motor mountings or as Paul says just accumulated gunge on the gears. Rich. |
17th Feb 2005, 3:52 pm | #4 |
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Re: Noisy electric clock
Hello Jeffrey,
don't know too much about clocks except for "my" noisy Smiths mantle!! Could the noise be due to intermittent lamination buzz, coupling with gear train noises? Tightening/twisting/levering might help point you in the right direction. Roger |
17th Feb 2005, 5:41 pm | #5 |
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Re: Noisy electric clock
Hello everyone!
I've got quite a few pre-war synchronous clocks, mainly Smiths/SEC but also a Magneta and some Ferrantis. Most have been dirt cheap and fairly tatty, looking as if they've lived in a garden shed or garage for a generation or two. But they all basically worked. Most noises are from the gear train in my experience. In fact I've never had buzzing laminations. If you're feeling brave and have got a couple of hours, you can strip the mechanism down and clean all the parts one by one, using an ultrasonic bath ideally, but I've also used isopropyl alcohol and a toothbrush successfully. Taking lots of pictures with a digital camera as it comes apart helps tremendously when it comes to putting things back. Re-assemble and lubricate. I've used a little 3-in-1 oil on the high-speed/low torque parts, and light general purpose grease at the other end of the drive train. Purists would be horrified, I'm sure, but it's got to be an improvment on what was there originally (i.e. nothing or rock-hard antique grease). The rotor often has adjustable and/or spring loaded bearings. As Roger implise, fiddle with these so that it spins freely but has minimal axial play. The first gear is often non-metallic, apparently sometimes SRBP (i.e. the same material that's used for most PCBs). This was done to reduce noise, but wear is often a problem after decades of use. I've often put a thin smear of the Electrolube Special Plastics Grease (SPG) that I use for videos on its teeth, and the grumbling noises usually then disappear completely. I'm not sure whether this is a good thing in the long term - and would appreciate the advice of any experts out there who know whether this could cause problems with the SRBP. Paul's use of WD40 isn't a bad one, and is certainly better than a dry mechanism. But the stuff gets everywhere, and theoretcically, the dust that will cling to it can cause wear in the long term. (I'd rather have a WD40'd clock than a WD40'd video anyday though - never buy a secondhand VCR that smells of WD40 ). Also check that any rubber suspension bushes that are used between the mechanism and the case aren't perished and hard. As Richard and Paul have said, later models were self-starting with a cunning device that reversed the rotor if it span up the wrong way. Early clocks just had a knob on the back with an arrow showing which way it should be spun. These work happily in either direction! But they're a pain if you live in an area which has frequent but short power cuts (sorry, power outages for those of you who heard last week's Feedback programme on Radio 4!). All the best, Nick. |
17th Feb 2005, 5:47 pm | #6 |
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Re: Noisy electric clock
Jeffery
Try cleaning the works with iso-propanol (or whatever the eurocrats call it now) or any thing else that may remove many years of accumulated gunge without upsetting the windings, and then lubricate it with nothing thicker than 3-in-1. I believe real clock repairers use a sharpened piece of wood (matchstick!!) to apply the oil to the right places ie bearings & possibly gear teeth. Its probably the motor bearings and the first couple of reduction gears that are causing it, after that everything will be moving too slowly. It may be, of course, that something made of Tufnol has worn in which case I can only suggest ear plugs. If it works then that should keep it going for another few decades. Joe |
17th Feb 2005, 6:22 pm | #7 |
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Re: Noisy electric clock
I think the noise is gear train rather than vibrating laminations. Being a coarse clock mender, I'll probably give it a good spray with propan-2-ol (I think that's the correct chemical name for isopropyl alchohol) and put a few drops of light oil on the bearings.
I'm not fussed about the reverse starts since I don't have to do it very often. In theory I think there's a mechanism in there that's meant to prevent reverse running but it's obviously broken. I listened to that Feedback prog. Maybe they should change the name to "Pedants Anonymous". Long live Fowler! |
17th Feb 2005, 6:47 pm | #8 |
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Re: Noisy electric clock
I understand that 3-in-1 is not particularly good quality oil (it deteriorates quite quickly). Sewing machine oil (from a major sewing machine brand) might be a better bet.
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17th Feb 2005, 6:56 pm | #9 |
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Re: Noisy electric clock
I've also used CaiLube X-10S precision instrument oil (by Caig Labs, Inc.) which is described as "non-gumming and long lasting" and to be used on "instruments, gears, gauges, mecahnisms, timers, clocks, guns" etc. etc.
I got it from CPC 5 years ago and it cost about £10 for a tiny 25mL bottle. But it goes a long way. I can't find it in their 2005 catalogue at a quick glance though |
17th Feb 2005, 8:53 pm | #10 |
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Re: Noisy electric clock
Jeffrey,
I would recommend dismantling the clock, as spraying with solvent tends to was dirt into the bushings (clock speak for plain bearing). Horologists use "peg wood", which is very soft, and similar in size to cocktail sticks, to clean out the bushings in the clock plates. You should really use clock oil to lubricate - I can bring a small quantity to Harpenden for you, if you wish (I use it on radio tuning drives), as it is a very light oil, and does not tend to form a gum, at least not for the first 10 years or so, and the professionals say that a mechanicla clock should be cleaned and lubricated every couple of years. Jim. |
17th Feb 2005, 10:25 pm | #11 |
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Re: Noisy electric clock
Jim
Thanks for the advice and the offer of clock oil. Seems like a fair swap for the graphite grease I don't think I should use that on the clock Jeffrey |
17th Feb 2005, 10:38 pm | #12 | |
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Re: Noisy electric clock
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Best regards, Paul |
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18th Feb 2005, 12:29 am | #13 |
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Re: Noisy electric clock
Paul,
conversly, they don't have as much power as a spring or weight driven clock, so it doesn't take much to stop them! I've also found that the plates are made of thin, and often poor qaulity metal, so they will wear quickly if there is any dirt in them. Plus, unless it is a chiming clock, it only takes a few minutes to strip and wash the thing anyway. In my last post, I meant to say you should only apply a drop (literally) of oil to each bearing. If they are the type with a countersunk hole on the outside of the plate, there should be just enough oil to fill the hole, but it shouldn't overflow - surface tension will hold the oil in. The early synchronous clocks have very low power motors, and need all the help they can get - less friction means less power, and therefore less noise. Jim. |
18th Feb 2005, 10:04 am | #14 |
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Re: Noisy electric clock
Everyone
A few comments on the above - I thought I would let the thread run for a while first. I speak as someone that has been restoring and making clocks for nearly half a century (and who has just donned flameproof clothing ) 3-in-1 and WD40 - NO! They are intended to 'creep' - clock oil is made to stay where you put it. Do not clean a clock in any way without dismantling it - you are just rearranging the muck Dunking a clock in, or spraying it with oil or any other lubricant just covers everything in it, resulting in a horrible sticky mess. Some clocks have a laminated stator that can buzz, but as several have pointed out, noise is probably either the rotor bearing or first stage of gearing. Clockmakers do not use matchsticks to oil with, they use oilers - steel tools with spear-shaped ends. They do, however, use sharpened pegwood (dogwood) sticks to clean pivot holes. Correct lubricants are thick (turret) clock oil for pivots, thin clock oil for sintered rotor bearings, light grease for first stage of gearing. Do not lubricate any other gear teeth. Sorry, Jim, oil sinks should never be filled - all exposed oil will deteriorate. In theory, the oil should all be in the annular space between the pivot and the hole. My 5cc bottle of clock oil that I have had for 20 years or so has, at a guess, now oiled about 100 clocks! I use always petrol to clean modern (post 1900) clock movements - soon it will be cheaper to use Lidl vodka . Self-starting motors always have a device to bounce the motor back if it starts the wrong way (which it has a 50% chance of doing). Taking Paul's point about them not being valuable, I try never to do anything that will be regretted in the future - many fine clocks (and radios) have been ruined in the past because at the time they were of no (financial) value - to me, there are other more important sorts of value! I am willing to help anyone off-list with any clock problems, electric or other!
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Mike. Last edited by Mike Phelan; 18th Feb 2005 at 10:09 am. |
18th Feb 2005, 6:21 pm | #15 | |
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Re: Noisy electric clock
Quote:
Good to hear from someone who's obviously been looking after clocks for a long time. Can I ask you a few questions? You advise "light grease for first stage of gearing". Could you explain a bit more, i.e. exactly where, and what grease you prefer. And what about those SRBP phenolic gears? A bit of grease on their teeth seems to calm a noisy clock, but what do you recommend? You also emphatically say "do not lubricate any other gear teeth"! Why's that, out of interest. I agree wholeheartedly that today's "worthless" junk could be tomorrow's highly sought-after collectables, and like to look after my old synchronous clocks as well as I can Cheers, Nick. Last edited by Nickthedentist; 18th Feb 2005 at 6:27 pm. |
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19th Feb 2005, 7:26 pm | #16 |
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Re: Noisy electric clock
I acknowledge all the horological wisdom, especially from Mike Phelan who has a vast amount of experience.
I was getting annoyed by the sound today but didn't have time to do any kind of decent job. I took the clock off the wall and noted that it ran more quietly when it was face down. I lifted off the back plate from the motor and the wound stator came away, leaving the rotor in mid air. The whole thing looks pretty rugged and there was obviously plenty of motor power so I indulged in some very coarse clock mending. I gave all the mechanism a liberal spray of IPA (the solvent, not the beer, even my clock mending isn't that coarse and anyway it's a waste of good beer) and put it all back together. It's a lot quieter now. I suppose I've redistributed all the muck and maybe even cleaned some off. I noted that there was a fair amount of end play in some of the shafts which may have contributed towards the noise. If the noise ever gets too annoying again I suppose I'll have to dismantle it and do a decent job. Jim: Thanks for the offer but I don't think I need the clock oil now. |
19th Feb 2005, 7:57 pm | #17 | |
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Re: Noisy electric clock
Quote:
I hope Mike dosn't mind me answering this one for him but the simple reason is that lubricants attract all sorts of dirt and dust, ultimately slowing the movement down David |
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19th Feb 2005, 8:27 pm | #18 |
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Re: Noisy electric clock
Thanks Dave, makes sense.
But it would be great if you could let me know about the other things, Mike Nick. |
19th Feb 2005, 11:28 pm | #19 | |
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Re: Noisy electric clock
Quote:
End play in shafts in electric clocks (and probably all clocks) can normally be solved by turning the works upside-down. Paul E |
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2nd Mar 2005, 8:53 pm | #20 |
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Re: Noisy electric clock
HI all,
I have just come across this thread and hope I am not too late to add my two penn'orth. Clocks and other miscellaneous brass bits and pieces such as radio knob inserts clean up very well if totally dismantled and soaked in a 10% sloution of very hot water and ammonia with some detergent such as Stardrops added. Don't use washing up liquid as it contains salt which can corrode any steel bits. Obviously don't do this to any electrical bits! Keep it near an open window or cooker hood as it is very smelly. Better keep SWMBO out of the way as well!! Soak for an hour or two and then wash well in clear hot water, dry, and polish if required. You can get special sawdist to dry it thoroughly but then you have to get rid of all the sawdust! This removes all accumulated hard oil, WD40, 3-in-1 and , unfortunately, any transfers. Petrol is good to remove any remaining remnants of polish. I have had good results with this solution for removing layers of paint from old bakelite telephone junction boxes, but I don't know how it works on radio cases. The pivot holes in spring or weight driven clocks wear in the direction of the thrust applied by the power source and often need re-bushing, but this is much less in electric clocks as there isn't a strong power source being regulated by an escapement. The main problem with electric clocks is around the motor bearings and gears as these are turning contunuously. Some electric clocks are actually of quite good quality and well worth adding to a collection of 1930s radios. The electrical safety is of a similar standard though with no thought of earthing the totally metal movement. A good source of proper oil and other supplies is Meadow and Passmore www.m-p.co.uk/ |