Timken Spindle Bearings?

Im trying to understand the reason the bearings need to be so precise. If you had a mid grade P6 with .0004 runout at each end of the headstock would the runout stay the same durning rotation of the bearings turning between the cone and race ? Even if it didn’t change I would think if one happened to be off 180* it would cause a taper ?
 
That is why precision bearing are marked for high spots. When one removes the spindle it should also be checked. Put on a precise set of v blocks and the high spot of spindle should be marked on both bearing surfaces. Once checked, bearings should be rotated to spindle to try and eliminate runout. Definately not a throw them on and install situation.
 
machPete99 said:
Yep the higher end bearings typically are just better picks from the main line.
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I don’t know about Timken, but at FAG that’s not true. The components may be taken from the main line, but they are measured and reworked to the level of precision needed. That is why they are so expensive, a significant amount of hand work is needed to get the higher levels of precision. Tolerances for normal precision bearings are fairly loose and can be run on high speed production machinery without the need for manual labor.
Barden Bearings for example only makes ABEC 7 and 9 bearings. The class 7 bearing components are measured at the production machines and run through the grinding/lapping machines until they pass, or are scrapped. For ABEC 9 bearings, the components are taken from the production line and brought into a temperature controlled room and measured to the required standards once they have reached the required temperature. There are specialized machines that are used only on the class 9 bearings in the temperature controlled room. The amount of process time and labor to go up from each class is significant, and the price reflects that.

If you want to get a potentially higher precision bearing at a normal cost, look for FAG X-Life bearings. FAG changed their process about 16 or so years ago and called it X-Life. These bearings are guaranteed at the normal P0 precision, but often meet P6 standards due to tighter process control than in the past, but that is not guaranteed! You could get a bearing that only meets P0, but in general it is a higher quality and precise bearing than what was available previously.
 
Well, thanks guys, a lot of info! As far as my ability to pay for bearings, I would get the better bearings for a hundred dollar or so increase in price. I probably would buy a bearing set of the same grade. But , I am not spending crazy money for a quarter of a thousand. I don’t need that degree of precision . Most of my stuff is just playing and building things where +or- .005 would work. When at the production machine shop,I learned my trade and worked at for a couple of years in the previous century, most of our tolerances were + - .005. But when doing the job on my lathe , I would like the most bang for my buck.
As for determining why I need bearings, it is mostly sound. Most lathes in good shape have a very pleasing “ whirr” . My lathe has a sound and ”feel” that I have come to associate with pitted bearings. It sounds like the spindle bearings to me. But I know sound can transfer and other things could cause the sound. I was a professional mechanic for most of my life and have chased “ sounds” many times. On my Clausing 6307 the top of the gear box comes off real easy and when I get to the point of addressing this problem, my first step will be removing the lid and a close inspection.
Again thanks, guys! I am amazed with the knowledge you guys have!




Bones
 
Ok, I thought that price on the 362A #3 precision cup was a mis print at $352! That probably is not going into my lathe! Lol! But for most of my stuff a swinging hatchet would work! Just don’t like the sound!






Bones
 
boneyard51 said:
Ok, I thought that price on the 362A #3 precision cup was a mis print at $352! That probably is not going into my lathe! Lol! But for most of my stuff a swinging hatchet would work! Just don’t like the sound!






Bones
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Radial runout in a rotating spindle comes from the inner race (cone).

Runout in the outer race (cup), does not rotate, as that race is pressed into the headstock, but manifests itself in the form of a slight angularity.

example: If your front/rear bearings are 16" apart, and the rear cup runout is .0002", and the front race has .0002" as well, putting the high side of both races on top results in no angularity. If the rear race high side is on the left, and the front race high side is on the right, it'll move your spindle axis alignment out by .0004" per 16". That can be adjusted out by a headstock alignment. If you can identify the high runout side of the cups (some bearings have this marked on the race), just mount them with the high sides on top, and your good.

If you used the cones listed previously, with the non precision cups, you would get much better runout than axle bearings, for not much more money. From the looks in the previous post, about 200$ total.

Those cones were listed as class 2 precision. Unless that is a misprint, it's a smokin deal. Class 2 is equivalent to Abec 9 / p2 precision. I actually suspect that's some kind of misprint, due to the low price of those cones.
 
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Ischgl99 said:
I don’t know about Timken, but at FAG that’s not true. The components may be taken from the main line, but they are measured and reworked to the level of precision needed. That is why they are so expensive, a significant amount of hand work is needed to get the higher levels of precision. Tolerances for normal precision bearings are fairly loose and can be run on high speed production machinery without the need for manual labor.
Barden Bearings for example only makes ABEC 7 and 9 bearings. The class 7 bearing components are measured at the production machines and run through the grinding/lapping machines until they pass, or are scrapped. For ABEC 9 bearings, the components are taken from the production line and brought into a temperature controlled room and measured to the required standards once they have reached the required temperature. There are specialized machines that are used only on the class 9 bearings in the temperature controlled room. The amount of process time and labor to go up from each class is significant, and the price reflects that.

If you want to get a potentially higher precision bearing at a normal cost, look for FAG X-Life bearings. FAG changed their process about 16 or so years ago and called it X-Life. These bearings are guaranteed at the normal P0 precision, but often meet P6 standards due to tighter process control than in the past, but that is not guaranteed! You could get a bearing that only meets P0, but in general it is a higher quality and precise bearing than what was available previously.
Click to expand...

Can I ask your background with regard to bearings? It sounds like you have personal experience working with/for a bearing maker.
 
Ischgl99 said:
I was the Industrial Services Manager for FAG Bearings in a previous life.
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Good man to have in the conversation! Notice you're from New Milford. A buddy of mine lives in Milford (I assume thwy're close) and has been introducing me to the fattening ways of New Haven apizza.
 
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ACHiPo said:
Good man to have in the conversation! Notice you're from New Milford. A buddy of mine lives in Milford (I assume their close) and has been introducing me to the fattening ways of New Haven apizza.
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Thanks, it’s been a number of years since I worked there, but I’ll help out where I can.

Milford is about an hour away, I’m up in the northwest hills and Milford is along the coast. Funny side story, we refinanced our mortgage twice a number of years ago when rates were falling and the mortgage company sent the lawyer to Milford instead of New Milford, twice! I grew up in NJ, I haven’t decided yet if New Haven or NJ pizza is better. I think I need to try a few hundred more slices before I call it either way :)
 
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