HMV 102 Auto brake query

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bikesteve
Victor Jr
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Location: Hong Kong

HMV 102 Auto brake query

Post by bikesteve »

Hi Folks,
Great site, very informative & helpful resource, I've lurked in the background way too long...
Been collecting & cleaning up 102's a few years now & have a query regarding the auto brake mechanism. There's a tight fitting brass? circular ring attached to the underside of the turntable (pictured) which acts as the actual brake. In the course of a strip down I usually separate the ring with pliers from the turntable & clean both as they're generally covered in oil/old grease, (possibly seeping from the motor..?)
-The question is, is there actually meant to be a tiny amount of grease between the ring and the turntable so it doesn't stop with too much of a jolt or was it designed to be completely free of any lubrication whatsoever?

Thoughts, opinions & advice much appreciated.

Cheers Steve
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Marco Gilardetti
Victor IV
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Personal Text: F. Depero, "Grammofono", 1923.
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Re: HMV 102 Auto brake query

Post by Marco Gilardetti »

As you have correctly written, the idea is that it should act as a friction. To make sure that the two parts don't grip over time, I would say that a drop of oil or grease is a good idea. The more progressively the turntable will halt, the less the motor will get a mechanical shock.

shoshani
Victor I
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Re: HMV 102 Auto brake query

Post by shoshani »

I've never given it that much thought; the auto stop works by catching that turntable projection and holding it fast; lubrication probably isn't going to help because the one part is firmly attached to the other - that's why it works in the first place.

I myself don't use the auto brake, because period publications such as Gramophone cautioned against using them because of motor shock. The earlier autobrakes on cabinet machines worked by tripping the handbrake, which had a pad either of leather or a compressed clothlike material, and could ease the turntable into the stop rather than jerking it suddenly.

BE WARNED: if you do any lubrication, make sure you do not attempt to lubricate the autobrake itself. It relies on fiber washers that must be kept dry and free from oil or grease, or else it will not function. (If those are faulty, replacements can be made from electrician's fiber paper, sometimes called "fish paper" by suppliers.)

bikesteve
Victor Jr
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Joined: Fri Apr 28, 2017 9:22 am
Location: Hong Kong

Re: HMV 102 Auto brake query

Post by bikesteve »

Cheers for the input guys. Yes I've always steered clear of lubricating the motor board part of the auto brake, great tip about the fish paper -most all the fibre washers are on their way out and disintegrate when dismantling.

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