bearings binding

[lee hawkins 1Participant @leehawkins1]

Hello

I decided to fit some new bearings to my mini lathe headstock . so I went for these, 7206 B 2RS Angular Contact Ball Bearing 30x62x16

These bearings fitted great. I have not given them any sort of preload for the reason being that I have not even fitted the locking nuts and On turning the spindlle there seems to be a slight binding as though there is too much preload.

When I turn the spindle, it turns kinda smooth but you can sort of feel the spindle click around with the rollers in the bearings

I have never had much to do with angular contact bearings, maybe these bearings fit differently

appreciate any advice

Thanks

lee

[lee hawkins 1Participant @leehawkins1]

[Mick B1Participant @mickb1]

You gotta suspect misalignment. IME the most usual cause is a particle at the bottom of the outer race seating bore, causing a thou or so tilt in said race.

Of course that's only a guess.

[HopperParticipant @hopper]

Good brand name bearings or Chinese no-name cheapies? Not all are created equal. Some of the cheapies are OK, others not so.

[lee hawkins 1Participant @leehawkins1]

Mick, Hopper

Yep!

I used block of wood to press out old bearings, a piece/splinter of wood managed to stick it's self to the bearing seat, cleaned it out, now perfect!

Thanks

lee

[oldveloParticipant @oldvelo]

Hi Lee

The outer bearing needs to be a sliding fit on the spindle not a press fit. The spindle under the bearing needs to be reduced with emery cloth until the bearing will slide on with finger pressure only.

They need a light preload with the back nuts are essential holding the inner races taking up the free play.

Eric

[not done it yetParticipant @notdoneityet]

The outer bearing needs to be a sliding fit on the spindle not a press fit.

That is surprising! So the inner race could turn on the spindle? Would that not possibly lead to wear on the spindle?

[Michael GilliganParticipant @michaelgilligan61133]

Posted by not done it yet on 09/09/2017 07:35:25:

The outer bearing needs to be a sliding fit on the spindle not a press fit.

That is surprising! So the inner race could turn on the spindle?

.

… but it should not

Unless the bearings themseves are very stiff [i.e. not fit for purpose]. The combined friction of the 'sliding fit' and the end-load will far exceed the rotational drag of the bearings.

MichaelG.

[Mick B1Participant @mickb1]

I'd guess the main purpose of making it a sliding fit is to provide 'feel' for the preload, without the additional drag of forcing the inner race along the spindle?

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