STD 305M main bearing question

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jives11
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Re: STD 305M main bearing question

Post by jives11 » 26 Dec 2015 09:48

I think moly is the nick name for molybdenum disulphide, as Alec says, perhaps a slight collar of moly grease around the upper part of the spindle might counter any upper spindle movement ?

Trio KD1033
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Re: STD 305M main bearing question

Post by Trio KD1033 » 26 Dec 2015 10:59

jives11 wrote:I think moly is the nick name for molybdenum disulphide, as Alec says, perhaps a slight collar of moly grease around the upper part of the spindle might counter any upper spindle movement ?
Ah, I see. I've got a tin of grease that came with the house, I'll see if it's suitable.
Thanks Jives11

Andy

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Re: STD 305M main bearing question

Post by jives11 » 26 Dec 2015 11:47

I think the trick is to run a fine thread of grease around the circumference upper part of the spindle. that way it wont smear down the inside of the well as you lower, it should stay put as a kind of lubricant washer around where some wear possibly has occurred.


The issue of the captive ball, did you try soaking the bearing well in alcohol or ligher fluid or a solvent over night . It could have got pretty stuck with dried oil

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Re: STD 305M main bearing question

Post by Trio KD1033 » 26 Dec 2015 11:54

jives11 wrote:I think the trick is to run a fine thread of grease around the circumference upper part of the spindle. that way it wont smear down the inside of the well as you lower, it should stay put as a kind of lubricant washer around where some wear possibly has occurred.


The issue of the captive ball, did you try soaking the bearing well in alcohol or ligher fluid or a solvent over night . It could have got pretty stuck with dried oil
I tried it first of all with some wd40 overnight, then cleaned that out and topped up with the usual synthetic oil. The ball did not budge.

Do I need something like ispropyl alcohol for this? I'm guessing white spirit or meths would cause some damage.

Andy

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Re: STD 305M main bearing question

Post by jives11 » 26 Dec 2015 12:05

I don't see how any of them would do any damage, and WD40 is a good solvent. Oh well, looks like its there to stay

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Re: STD 305M main bearing question

Post by Copperhead » 26 Dec 2015 13:52

Have you shined a torch down the well and are you sure there is a ball there? Adding grease to a porous bearing will cause the pores to clog up, not sure about this "grease washer" on the top bearing. A thicker oil will take up any slack, grease is usually just applied, in moderation, to the bottom of the spindle where it mates with the ball bearing or thrust pad.
Or in a bearing specifically made to be greased.

The wear on the dome of your spindle shows that the spindle has been rubbing against something, maybe the ball has sank in whatever it rests on and this is why it will not come out. Pointless adding grease, or any type of thick oil, until you know whether there is a ball and if indeed said ball is of the right size. The spindle has definitely been rubbing against something, also looks as if someone has tried sanding it. The only marks one would expect are circular, the bottom of the spindle looks as if scratched by some abrasive.

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Re: STD 305M main bearing question

Post by Trio KD1033 » 26 Dec 2015 14:16

Copperhead wrote:Have you shined a torch down the well and are you sure there is a ball there? Adding grease to a porous bearing will cause the pores to clog up, not sure about this "grease washer" on the top bearing. A thicker oil will take up any slack, grease is usually just applied, in moderation, to the bottom of the spindle where it mates with the ball bearing or thrust pad.
Or in a bearing specifically made to be greased.

The wear on the dome of your spindle shows that the spindle has been rubbing against something, maybe the ball has sank in whatever it rests on and this is why it will not come out. Pointless adding grease, or any type of thick oil, until you know whether there is a ball and if indeed said ball is of the right size. The spindle has definitely been rubbing against something, also looks as if someone has tried sanding it. The only marks one would expect are circular, the bottom of the spindle looks as if scratched by some abrasive.
I have Vinnie, the issue I have is that you can light up the bottom of the assembly, but as soon as you try to look in, you block the light. I think that I will try to get a photo of it with a tripod and long shutter speed. It certainly felt like a dome at the bottom though, when I touched it with a cotton bud.

Andy

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Re: STD 305M main bearing question

Post by Copperhead » 26 Dec 2015 14:44

Trio KD1033 wrote:
Copperhead wrote:Have you shined a torch down the well and are you sure there is a ball there? Adding grease to a porous bearing will cause the pores to clog up, not sure about this "grease washer" on the top bearing. A thicker oil will take up any slack, grease is usually just applied, in moderation, to the bottom of the spindle where it mates with the ball bearing or thrust pad.
Or in a bearing specifically made to be greased.

The wear on the dome of your spindle shows that the spindle has been rubbing against something, maybe the ball has sank in whatever it rests on and this is why it will not come out. Pointless adding grease, or any type of thick oil, until you know whether there is a ball and if indeed said ball is of the right size. The spindle has definitely been rubbing against something, also looks as if someone has tried sanding it. The only marks one would expect are circular, the bottom of the spindle looks as if scratched by some abrasive.
I have Vinnie, the issue I have is that you can light up the bottom of the assembly, but as soon as you try to look in, you block the light. I think that I will try to get a photo of it with a tripod and long shutter speed. It certainly felt like a dome at the bottom though, when I touched it with a cotton bud.

Andy
Andy, if there is a dome, it should still be able to be removed. I know there are other members here using the 305, hopefully one will shine a light (pardon the pun) on the issue.
Normally, if anything but a ball is used, the bottom of the bearing assembly would be removable.

There should be "sacrificial" mating surface in there somewhere, one which is replaceable as it wears.
By the way, where in the UK are you? I could polish the bottom of the spindle, gratis, if you like. Thing is, I don't know what the spindle on the 305 is made of. Might be chromed, you would be amazed at how many decks used chromed brass in their bearings. The KD-1033, for instance.

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Re: STD 305M main bearing question

Post by Trio KD1033 » 26 Dec 2015 15:45

Copperhead wrote:
Trio KD1033 wrote:
Copperhead wrote:Have you shined a torch down the well and are you sure there is a ball there? Adding grease to a porous bearing will cause the pores to clog up, not sure about this "grease washer" on the top bearing. A thicker oil will take up any slack, grease is usually just applied, in moderation, to the bottom of the spindle where it mates with the ball bearing or thrust pad.
Or in a bearing specifically made to be greased.

The wear on the dome of your spindle shows that the spindle has been rubbing against something, maybe the ball has sank in whatever it rests on and this is why it will not come out. Pointless adding grease, or any type of thick oil, until you know whether there is a ball and if indeed said ball is of the right size. The spindle has definitely been rubbing against something, also looks as if someone has tried sanding it. The only marks one would expect are circular, the bottom of the spindle looks as if scratched by some abrasive.
I have Vinnie, the issue I have is that you can light up the bottom of the assembly, but as soon as you try to look in, you block the light. I think that I will try to get a photo of it with a tripod and long shutter speed. It certainly felt like a dome at the bottom though, when I touched it with a cotton bud.

Andy
Andy, if there is a dome, it should still be able to be removed. I know there are other members here using the 305, hopefully one will shine a light (pardon the pun) on the issue.
Normally, if anything but a ball is used, the bottom of the bearing assembly would be removable.

There should be "sacrificial" mating surface in there somewhere, one which is replaceable as it wears.
By the way, where in the UK are you? I could polish the bottom of the spindle, gratis, if you like. Thing is, I don't know what the spindle on the 305 is made of. Might be chromed, you would be amazed at how many decks used chromed brass in their bearings. The KD-1033, for instance.
Here we are, I managed to get a picture of the bottom:
https://farm6.staticflickr.com/5709/236 ... 79da_b.jpgSTD 305m Bearing by Andy Likes Cameras, on Flickr
https://farm2.staticflickr.com/1471/238 ... 1682_b.jpgSTD 305m Bearing by Andy Likes Cameras, on Flickr

Doesn't look like a ball does it? Even though it feels domed.
I'm in Lincolnshire, Vinnie. I must admit I don't know if the spindle is chromed or not.
That's a very kind offer though!
I wonder if the ball sat on a raised surface, it would explain why the bearing spins fairly well, and also the strange wear patterns. Of course, if it is missing, how on earth do I select the right size replacement!

Andy

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Re: STD 305M main bearing question

Post by Copperhead » 26 Dec 2015 16:24

Great photograph, Andy, very impressed. Difficult to tell, but it does look like a concave on top of a convex! If that is dimple, it is missing the ball.

Maybe the two domed surfaces create some sort of oil bath.

I dare say the size of the ball can't be that difficult to work out. A bicycle shop should stock a few sizes, it will take a bit of experimenting. Don't keep using the turntable, the spindle cannot be replaced cheaply.

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Re: STD 305M main bearing question

Post by Trio KD1033 » 26 Dec 2015 16:33

Thanks Vinnie.
I'm glad I took another look now! I'm surprised that the platter height was spot on, it's probably had the suspension adjusted to compensate. The spindle is about 7mm so I guess around 6.5mm and less. Not really clued up on ball bearing sizes! I'll just have to make sure I don't get one stuck.

Edit: I have a Rega Planar 3 spindle bearing to compare it to, and it's smaller than that.

Andy

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Re: STD 305M main bearing question

Post by Trio KD1033 » 26 Dec 2015 17:16

Apparently the Planar 3 ball is 4.77mm, so I guess that the ball I need is a fair bit smaller than the spindle size. I've found a supplier called "Simply Bearings". They have chrome hardened bearings of all sizes. One thing's for sure, I'll have a lot of spares!

Andy

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Re: STD 305M main bearing question

Post by Copperhead » 26 Dec 2015 18:21

Trio KD1033 wrote:Thanks Vinnie.
I'm glad I took another look now! I'm surprised that the platter height was spot on, it's probably had the suspension adjusted to compensate. The spindle is about 7mm so I guess around 6.5mm and less. Not really clued up on ball bearing sizes! I'll just have to make sure I don't get one stuck.

Edit: I have a Rega Planar 3 spindle bearing to compare it to, and it's smaller than that.

Andy
You're welcome, mate. I don't want to make things more complicated, but in some bearing designs the ball is held captive by the shape of the spindle.
Remember that a ball bearing will be harder than the spindle, if the spindle were to turn on the ball it would wear out more quickly than it.

Lenco's spindles are conically concave, the ball "jams" in the concave and only spins on the thrust pad, which is some sort of Delrin.The Delrin would be the "sacrificial" material.

I reckon a phosphor bronze ball would be ideal in your bearing, it would wear before any of the other parts and could be replaced easily.

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Re: STD 305M main bearing question

Post by Trio KD1033 » 26 Dec 2015 18:31

Most of the bearing suppliers seem to supply stainless steel, or chromed steel with a hardness rating of 60 to 67 hrc for chrome and 52 to 55 for steel. I don't know what hrc is by the way! Any idea where I could get a bronze ball from?

Thanks for all your help
Andy

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Re: STD 305M main bearing question

Post by Copperhead » 26 Dec 2015 18:56

Trio KD1033 wrote:Most of the bearing suppliers seem to supply stainless steel, or chromed steel with a hardness rating of 60 to 67 hrc for chrome and 52 to 55 for steel. I don't know what hrc is by the way! Any idea where I could get a bronze ball from?

Thanks for all your help
Andy
I can't remember where I bought some, these might be too big? http://www.ebay.co.uk/itm/5-16-Phosphor ... xyXzxTHfOi A flat will eventually appear, the ball can then be rotated to offer a different face. Once worn, you can replace it!

The hrc is a measure of hardness, the Rockwell scale. How hard a ball bearing need to be in a turntable application is debatable, one of the most important considerations is how smooth it is. Obviously, too soft and it will wear. Don't bother getting tempted by ruby or ceramic overprized bearings.