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  #31  
Old 12-08-17, 03:47 AM
Bob B. Bob B. is offline
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Oh dear. Typo. I must stop drinking a couple of bottles of red on a Friday night. It was supposed to read 70 degrees. No maths involved. Purely found in some of my old notes from a long time ago. Don't read my posts late on a Friday night. Cheers guys.
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  #32  
Old 12-08-17, 03:58 AM
Tony L Tony L is offline
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I've yet to observe a turntable main bearing housing at anything above ambient room temperature. I'm sure if it was 70% at the contact point that would radiate out and warm the housing. Motors are whole other things, the big old idler decks I like do run very warm.
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  #33  
Old 12-08-17, 04:07 AM
Barrymagrec Barrymagrec is offline
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If the 70 degrees is correct it would only be at the tip, heat dispersal through the shaft and thrust would be virtually instantaneous, apart from anything else, if there was sufficient friction to warm up the whole bearing housing and shaft to 70 degrees you would need a much more powerful motor to drive it and the belt would snap.
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  #34  
Old 12-08-17, 04:32 AM
TPA TPA is offline
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Quote:
Originally Posted by Tony L View Post
I've yet to observe a turntable main bearing housing at anything above ambient room temperature. I'm sure if it was 70% at the contact point that would radiate out and warm the housing. Motors are whole other things, the big old idler decks I like do run very warm.
I have no idea what the tip temperature is but the mass of the rest of the spindle and platter will soak that up and of course the whole assembly is running in an oil bath so that will reduce temps considerably. Either way there is little chance of the whole bearing generating much heat above ambient temperatures. If you were to run it at a much higher rpm and remove the oil then you'd find temperature and wear rate would rise significantly.

The factors that contribute to the bearing running quietly also involve things like how concentrically the tip is located which would increase scrub etc. Probably one of the reasons some manufacturers like to use a ball bearing against a flat spindle surface, potentially a cheap way to do this (if you can correctly locate the ball)
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  #35  
Old 12-08-17, 04:42 AM
Bob B. Bob B. is offline
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Quote:
Originally Posted by TPA View Post
I have no idea what the tip temperature is but the mass of the rest of the spindle and platter will soak that up and of course the whole assembly is running in an oil bath so that will reduce temps considerably. Either way there is little chance of the whole bearing generating much heat above ambient temperatures. If you were to run it at a much higher rpm and remove the oil then you'd find temperature and wear rate would rise significantly.

The factors that contribute to the bearing running quietly also involve things like how concentrically the tip is located which would increase scrub etc. Probably one of the reasons some manufacturers like to use a ball bearing against a flat spindle surface, potentially a cheap way to do this (if you can correctly locate the ball)
Ok to clarify. I am giving you data I got from the numerous Linn guys I spoke to at the time. I visited the factory in Drakemire drive more than a few times. The figure of 70 farehheit was the heat generated at the point contact and was what the lubricant had to deal with at that point. I agree the mass off the spindle plus the inner/ outer platter and the amount of oil in the housing would dissipate this to ambient temp. I was also imformed at the time that it was normal for a small part of burnt oil deposit was quite normal to be seen on the end of the tip.
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  #36  
Old 12-08-17, 06:06 AM
Mynamemynaim Mynamemynaim is offline
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Originally Posted by Barry williams View Post
You obviously have know idea what you are talking about.

Obviously....As you don't agree with me...
( By the way ..it's No idea ..not know)

Last edited by Mynamemynaim; 13-08-17 at 01:03 AM.
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  #37  
Old 12-08-17, 06:03 PM
chiily chiily is offline
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I'm still intrigued by the oil that has hardened due to heat now we've established that we are talking about 70degF.
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  #38  
Old 13-08-17, 12:52 AM
RustyB RustyB is offline
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Anyone know what oil is recommended for the very early (bronze coloured) bearing?
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  #39  
Old 13-08-17, 01:36 AM
nitrous nitrous is offline
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Originally Posted by chiily View Post
I'm still intrigued by the oil that has hardened due to heat now we've established that we are talking about 70degF.
Could it just be a blob of the molyslip that has accumulated and not burnt oil? The stuff does tend to settle out of the oil over time, which is why you have to shake the bottle of Linn 'black' oil to disperse it.
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  #40  
Old 13-08-17, 01:43 AM
Tony L Tony L is offline
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There is also a good chance a different oil has been added without flushing the original out properly in very old bearings, e.g. there might be a mix of organic and synthetic or whatever in some bearings. Linn bearings are far harder to clean than the old Garrard/Thorens/Lenco types with their detachable thrust plates. To be honest I never found a technique I was happy with.
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  #41  
Old 13-08-17, 02:10 AM
Robert Robert is offline
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Perhaps it's just me, but in 30+ years of using quality decks from Rega, Linn, Roksan, Ariston, Sytremdec, Micro, Technics.....and so many others....I've never encountered one with a bearing noise issue.
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  #42  
Old 13-08-17, 02:17 AM
Tony L Tony L is offline
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Quote:
Originally Posted by Robert View Post
Perhaps it's just me, but in 30+ years of using quality decks from Rega, Linn, Roksan, Ariston, Sytremdec, Micro, Technics.....and so many others....I've never encountered one with a bearing noise issue.
Agreed, even the LP12 bearing with a big flat-spot I chucked out sounded fine to my ears! I'm now used to vintage idler decks and the main bearing is the least of ones worries when it comes to noise. By saying that my TD-124 has a fancy Schopper main bearing that cost as much as a pretty decent turntable on its own!
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  #43  
Old 13-08-17, 06:03 AM
Bob B. Bob B. is offline
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This is now testing my memory. I think it was around 1987 Linn changed the bearing to the black liners with the black oil. All I can say is I was 33 years old at the time. I had noticed the black deposit on not only my then newish Lp12 at the time but also on my friends deck. It was also visible on the dem. decks in the shop. They were all relatively new. I then asked Martin the next time I was at the factory and that was the explanation I was given. I took it as gospel. I was told not to try and remove it as it may damage the point. I can assure you all these decks were running original oil and fairly new.. Never flushed out or changed. I believed that explanation as it was coming from the horses mouth so to speak. Nitrous could be right. with his explanation. All I know is it never seemed to cause any detriment. The main point relating to the Ops. post is do not attempt to use any abrasive on the polished surface. I have my newish Lp12 running downsairs but I am reluctant to remove the inner platter just to check for a black blob of oil burnt or otherwise. Maybe someone else would like to have a look. It is possible they have changed the formulation since 1987 anyway.
Bob.

Last edited by Bob B.; 13-08-17 at 06:43 AM.
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  #44  
Old 13-08-17, 08:07 AM
YNWOAN YNWOAN is offline
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Quote:
Originally Posted by Robert View Post
Perhaps it's just me, but in 30+ years of using quality decks from Rega, Linn, Roksan, Ariston, Sytremdec, Micro, Technics.....and so many others....I've never encountered one with a bearing noise issue.
How do you know Robert? Do you mean you've never heard an obvious scraping noise from the speakers - well, err, no - obviously not; the bearing noise would be catastrophic by then. However, when bearing noise is reduced the effect is quite obvious.
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  #45  
Old 13-08-17, 08:29 AM
Robert Robert is offline
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Quote:
Originally Posted by YNWOAN View Post
How do you know Robert? Do you mean you've never heard an obvious scraping noise from the speakers - well, err, no - obviously not; the bearing noise would be catastrophic by then. However, when bearing noise is reduced the effect is quite obvious.
Reduced from what to what though?

I know because I've used decks with very low noise, eg new form the box LP12 and technics DD where the noise spec is state of the art. On switching to 'lesser' decks such as the Rega Planar 3, or a Dual with less well engineered bearings, there is no perceptible degradation. Record surface noise always dominates, or motor noise if they aren't well isolated.
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