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 Post subject: HMV 102 Auto brake query
PostPosted: Thu Feb 13, 2020 11:07 am 
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Victor Jr
Joined: Fri Apr 28, 2017 9:22 am
Posts: 12
Location: Hong Kong
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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 Post subject: Re: HMV 102 Auto brake query
PostPosted: Thu Feb 13, 2020 11:40 am 
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Victor III
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F. Depero, "Grammofono", 1923.
Joined: Thu Feb 24, 2011 4:19 am
Posts: 961
Location: Italy
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.


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 Post subject: Re: HMV 102 Auto brake query
PostPosted: Thu Feb 13, 2020 2:44 pm 
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Victor Jr
Joined: Fri Mar 17, 2017 2:52 pm
Posts: 40
Location: Chicago
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.)


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 Post subject: Re: HMV 102 Auto brake query
PostPosted: Thu Feb 13, 2020 7:37 pm 
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Victor Jr
Joined: Fri Apr 28, 2017 9:22 am
Posts: 12
Location: Hong Kong
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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