# Atlas 3950 bearing question



## mlorsung (Feb 21, 2013)

Hey all,
I hope this isn't a completely idiotic question, I am new here and to machining more or less, so please bear with me.  I have an atlas 3950 that i picked up with some tooling for a couple hundred bucks.  i checked the spindle and there is no play in it to speak of, but I did notice that it has the NTN bearings in it, which I believe I read somewhere might need to be replaced.  If the spindle doesn't have play in it, is it worth doing, or should i simply wait for them to fail at some point and then  replace them?  If anyone has any other tips or thoughts on this machine, I'm all ears.

Thanks,
Michael


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## bustamallard (Feb 22, 2013)

I am not real familiar with that particular machine, but it has been my experience that even when there is no play you might detect issues by looking at the surface finish of a turned part (under power feed preferably). You should be looking for regular patterns caused by vibrations in the spindle. Also, you might want to try using a mechanics stethoscope, it's amazing what you can hear with those.  These types of bearings are pretty tough though, so if you try the above suggestions and everything checks out you should be very pleased with your purchase


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## mlorsung (Feb 22, 2013)

bustamallard said:


> I am not real familiar with that particular machine, but it has been my experience that even when there is no play you might detect issues by looking at the surface finish of a turned part (under power feed preferably). You should be looking for regular patterns caused by vibrations in the spindle. Also, you might want to try using a mechanics stethoscope, it's amazing what you can hear with those.  These types of bearings are pretty tough though, so if you try the above suggestions and everything checks out you should be very pleased with your purchase



Thanks for the advice, I'll chuck something up tonight and make some cuts using the power feed


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