LP12 main bearings: Cirkus + Tranquility, Mober, Karousel

[YNWaN]

Oh, is it . I measure it as best I could with my verniers and thought the pitch was likely 1mm. I've ordered a nut to that spec so we shall see.

Do you know what thread spec you ordered?

[ChrisOH1]

He did say but I don't recall. Apparently the issue is its a type not typically used on the 1" diameter the bearing is. A local engineering company are making them for me. Les told me the bearings were made in Sheffield by someone long retired.

[YNWaN]

Oh it’s possibly whitworth - but it’s a bit bonkers if that is the case - though it’s possible that the lathe Les had was too old to cut metric threads.

[jimification]

Why is nothing ever as straightforward as it should be? Keeps things interesting, I suppose Are you saying Linn don't make the Karousel? (they do seem to contract out a lot of stuff)

[YNWaN]

Chris is talking about his deck which he is refurbishing. The bearing on that is also attached in a similar way to the Karousel.

Linn do seem to farm out a lot of their engineering and I’ve no idea if they make the Karousel themselves - but it wouldn’t surprise me if they did not. I’m sure they don’t make the bearing liners (though they will be made to Linn’s specification) and I would be very surprised if they make the thrust pad. Under close inspection the bearing liners in the Karousel look to be the same as those used in the Cirkus.

[jimification]

Ah, misunderstanding, sorry. Thanks for the explanation.

[YNWaN]

I’ve been doing a ton of measuring and drawing and the Karousel is nicely made. I can also confirm absolutely that the thread used to attach it is 1mm pitch metric fine (sometimes called super-fine).

I’ve also managed to undo the lower section that houses the thrust pad. I found this surprisingly easy to do as it wasn’t done up very tightly at all. In fact I was able to hold the main part of the bearing in my hand and simply undo the lower cap with an adjustable spanner. Looking closely at the design you can see the lower cap bears U.K. against a surface that is part of the main body. This is sufficient to compress the sealing o-ring without crushing it. The main internal tolerances of the bearing are extremely good.

[jimification]

Thank you, Mark. I'm very pleased to hear that the pitch is something commonly available. That opens up some much simpler possibilities for trying it with a Tranquility.

[YNWaN]

Hey Jim . Well, it’s not a custom thread but it’s not that common either unfortunately. I actually couldn’t find any stainless steel nuts on a eBay in M16 super-fine and had to buy hardened steel ones. This goes to show how relatively rare this thread is because there are thousands of types of SS fasteners on eBay to choose from.

Having said that I’ve just found some on Amazon .

[YNWaN]

Right, I’ve thoroughly measured and drawn up the Karousel (have yet to create the custom thread in Solidworks as it only has M16 x 1.5 as standard). So I’ve put it all back together exactly as it was and will be posting it back to Jim tomorrow (weather permitting).