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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 May 2010, 1:47 pm | #1 |
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F&S massager
At the NVCF I bought this vintage massager. The only clue to the maker is a small oval (just visible in photo) engraved with Made in England surrounding the characters F&S who I presume were the makers. The only other evidence is the 230/250 engraved on the case and a the number 5877 also engraved. There are 2 toggle switches, one for on/off the other for 2 speeds. There is a selection rubber and plastic heads that can be screwed into the main unit.
Does anyone know anything about this? Who were F&S and what else did they do? Google has failed dismally. Last edited by Paul Stenning; 13th May 2010 at 9:03 am. Reason: Thread tidying |
10th May 2010, 5:53 pm | #2 |
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Re: F&S massager
Particularly judging by the similarity of design of the attachment shown (I didn't get a good look at the rest yesterday), this may be an earlier version of the "Pifco electric vibratory massager", which has the perfectly innocent function of easing muscular pain. I wonder whether F&S became (part of) Pifco.
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Mending is better than Ending (cf Brave New World by Aldous Huxley) Last edited by Paul Stenning; 13th May 2010 at 9:03 am. Reason: Thread tidying |
10th May 2010, 6:19 pm | #3 |
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Re: F&S massager
The attachments on the Pifco look very similar to those on my F&S. Including the screw fixing and "butterfly" locknut.
This page suggests that my unit is certainly pre-1948 and likely pre-1935. http://homepage.ntlworld.com/paul.li...massagers.html These photos are perhaps nearer the mark. http://www.***********/photos/gaetanlee/4181360111/ |
10th May 2010, 7:55 pm | #4 |
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Re: F&S massager
Sorry Jeffrey,no we are not that tough!! Certainly doesnt look as safe as medical equipment today that a certainty.
PS No offence intended to anybody David |
10th May 2010, 10:52 pm | #5 |
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Re: F&S massager
The machine does look very much pre-war, although I wonder if the rubber head has been transferred from a later Pifco set?
I'm struggling with 'F&S' - any chance of a pic of the logo in case it jogs a memory? My first hunch was Falk, Stadelmann & Co. of lighting fame, who also sold small appliances and accessories. They were badged variously 'Falks', 'Efesca' and 'F.S. & Co' but evidently not 'F&S'. Lucien |
11th May 2010, 9:47 am | #6 |
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Re: F&S massager
Here's the logo.
I think somebody has worked on this machine fairly recently. Taking out the switch panel it looks like PVC wiring behind. |
11th May 2010, 11:48 am | #7 |
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Re: F&S massager
Hello Jeffrey,
Probably nothing to do with this at all, but F&S was a mark of Fattorini and Sons (Birmingham/Bradford?) who made badges etc http://www.google.co.uk/imgres?imgur...%257CcountryGB Michael |
19th May 2010, 8:20 pm | #8 |
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Re: F&S massager
Although it's been worked on the insulation resistance is poor. Using my 500V megger it's about 100K when cold, dropping to about 25K after a few minutes running. That's when it tripped the RCD - wouldn't like to run it without.
I'm a bit nervous about dismantling motors - my attempts many years ago always seemed to leave wreckage. As far as I can see, I should remove the brushes (easy) and undo the 2 bolts that hold the motor housing together. I think whoever worked on it used a lot of thin grease or thick oil. I unscrewed the rotary to vibration device on the front of the motor and the inside was smothered in the stuff. The brushes seem to be covered in it too. Judging by the colour it might be graphite based which certainly wouldn't help the insulation. Any further opinions on the maker? |
19th May 2010, 11:07 pm | #9 |
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Re: F&S massager
We've got one somewhere still in its box, but no idea of the make, probably the prolific Pifco. We also have a crank-operated one, looks a little like a hand drill.
The earth leak will either be carbon brush-dust thats built up around the brush boxes and comm, (assuming its a universal AC/DC motor), conductive grease thats oozed out of the bearings, possibly as a result of over eager lubrication, or else the elephantide paper has become a little damp..this is the shellacked paper that lies in between the armature poles and around the field coils. This might benefit from gentle stoving in a low oven, commercial motor overhaulers use this technique to improve the insulation value especially if the motor has been disused in storage for some time. Even running them without the earth (and suitably insulated & isolated of course) until they get warm can improve the earth leakage. I look forward to pictures of it back in use!
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20th May 2010, 7:40 am | #10 |
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Re: F&S massager
I did run it to warm it through. The result was the insulation getting worse. Maybe I should have run it for longer. I think I will have to strip and clean it.
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20th May 2010, 9:33 am | #11 | |
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Re: F&S massager
Quote:
What I have noticed with my experiments with vacuum-restoring waxy capacitors is that leakage due to damp insulators goes up exponentially with temperature. This makes it very hard to assess small improvements or otherwise in treatments aimed at changing things. What this means is that to be able to measure insulation changes to say 10% accuracy you need to fix the temperature to better than 1 degree C. |
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20th May 2010, 9:53 am | #12 |
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Re: F&S massager
Worse when warm. Went back to 100K when cold. Seems repeatable. I'll live with 100K though it's hardly wonderful but 25K is leaking enough to trip my RCD. (Most 30mA nominal RCDs will actually trip at between 10 and 20mA)
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20th May 2010, 10:05 am | #13 |
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Re: F&S massager
There's often a strong inverse relationship between insulation resistance and temperature especially in larger machines where the bulk characteristics of the materials tend to dominate over local irregularities. Sometimes the curve itself is a useful indicator of condition, as you can identify whether a single breakdown or general degradation is responsible for a poor reading at the terminals.
25k suggests something is amiss unless it's visibly wet. The lowest reading I have ever got from a damp machine that was not actually faulty was about 8k IIRC, but that was a 1000A dynamo with condensation dripping from its foot-long commutator. I'd avoid running a mains voltage motor at 25k, if it's a single fault with anything like mains across it there could by up to 2W dissipated in it, which will quickly char the surrounding insulation. Lucien |
20th May 2010, 11:14 am | #14 |
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Re: F&S massager
I've taken off the end plate that covers the commutator etc and desoldered the leads to the brush holders. Everything leaks! The rotor leaks a bit, the stator rather more and the brush holders leak too. There's definitely too much thin oil been sprayed around everywhere.
The brush holders should be the easiest to get right. Looks like 2 phenolic inserts held in by grub screws so a good clean up should work. The rotor isn't too bad but really not sure how to go on with the stator. PS: Taken a closer look at the brush holders etc. There's a modern-ish dual suppressor cap connected from each brush holder to the case. There is oil soaked sleeving over the leads and that's what's leaking. Seems quite possible that all the leakage is down to conductive oil over everything. Still not sure what to do about the stator. I suppose I could give the whole lot a good wash in IPA and dry it in a low oven but I'd be worried about damaging the windings. Last edited by ppppenguin; 20th May 2010 at 11:22 am. |
20th May 2010, 11:56 am | #15 |
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Re: F&S massager
Cleaned up the brush holders and they are fine now. The dual cap is leaky as was the sleeving on its leads. Yuk. What's the best way to suppress arcing at the com? I've got some 4.7n Y2 caps. One from each side of the com to the case? Or direcly across the com? Or something else altogether?
PS: There's definitely something odd about this device. All internal wiring is PVC, all the way to the stator windings which doesn't tally with the likely age. Suggests it might have been rewound relatively recently. or possibly even some kind of modern repro unit. the latter seems most unlikely - it's a bit too solid and chunky for that. Last edited by ppppenguin; 20th May 2010 at 12:02 pm. |
20th May 2010, 5:45 pm | #16 |
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Re: F&S massager
Decided to bake the rotor and stator. An hour in the gas oven on "S", th slowest setting. The stator is now excellent, better than 50M. The rotor got worse but is now better than 10M after cooling off. Was only about 2M before the bake.
I've cleaned out all the oily muck. A little oil will go in the main bearings and some LM grease in the rotary to vibration device. I found 2 loose nuts in the muck round the rotate to vibe. Can't see what they were for. I'll reassemble without and see. Also lost a tiny grub screw but it's not vital for operation. |
20th May 2010, 7:57 pm | #17 |
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Re: F&S massager
My mother used to lubricate her electric whisk with cooking oil until I told her not to.
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20th May 2010, 8:26 pm | #18 |
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Re: F&S massager
It's back together and working. I has just run for 10 minutes off load and the insulation resistance is still better than 1M overall.
It is mechanically quite stiff and certainly gets quite warm. Warmer than I remember it before the dismantling. Won't run at all on the lower setting. This seems to be applying mains to a different tap on the field coil. It did run on this setting before dismantling, albeit rather raggedly. Minimal arcing at the commutator though a very occasional arc running half way round. Maybe I should remove one of the packing washers on the shaft. Advice from the motor experts would be appreciated. |
20th May 2010, 9:40 pm | #19 |
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Re: F&S massager
Impressive results from the baking. I wonder how, given the state of oil impregnation, there was such a high moisture content. Oil attacks organic insulating materials but I can't see that it would have been responsible for the low reading itself. The PVC is odd indeed. Perhaps the coils have been retaped with the new leadouts attached. If it has been rewound in the PVC era, I'd not have expected the insulation to be so hygroscopic.
I don't think it should be stiff. The mechanical output of these motors is pretty small. What makes you want to remove a shaft shim? If you do, take care that resulting endfloat doesn't cause the brushes to jump in and out of any groove that has formed in the comm. If the armature runs in plain bearings they might not be self-aligning, in which case you have to play with the end brackets and jiggle them until it's right. Arcs flying round the commutator sometimes indicate faulty coils, but perhaps in this case just residual shorts between segments. Is the comm undercut or moulded solid? If it's cut try cleaning out the grooves again. Brushes saturated with oil and then disturbed can rapidly deposit conductive paste almost like dag as they wear in. Check coils individually with a meter - if one is bad it might be readily spotted on a tiny motor like this due to the high coil resistance. Minor sparking at the trailing edges of the brushes is normal and almost unavoidable in small universal motors because they rely on the brush resistance to impose the necessary volt-seconds to reverse the current in each coil as it passes. Running fast, using mains voltages across a small number of coils, and being cheaply made all hamper clean commutation. You won't stop the sparking but the normal way to minimise RFI is a lead-through cap on the supply cable side of the field, presuming the field is connected either side of the armature? Lucien |
20th May 2010, 9:57 pm | #20 |
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Re: F&S massager
I think the "oil" was largely graphite grease which would explain a lot. For example the fabric sleeving on the leads of the old suppressor cap was both oily and conductive. In retrospect I wonder if the stator was actually pretty much OK and I was deluding myself somewhere. Most of the leakage is now from the rotor. All the coil resistances are sensible, in the few 100 ohms range. I'm slightly surprised to find that the motor is series wound. I would have expected shunt wound to prevent it reaching silly off load speeds. Or is shunt wound impossible for a universal motor?
I've never adjusted bearings before. It looks like one of those impossible jobs since each bearing has three screws whcih are only accessible from inside the case. I think the rotor is clamped up a bit tight between the bearings hence the idea of removing a shim. Doesn't hurt to try. If it frees up the shaft without introducing float then I've got the answer. I'll give the com another clean though there's very little arcing at the moment. |