ER Ball Bearing Collett Nut – Care and Maintenance

[PeroParticipant @pero]

Lubrication and Grit in Bearing

[PeroParticipant @pero]

Hi

First the drawn out history to the problem.

A while back I purchased some ball bearing collet nuts from a well known supplier (name suppressed for protection of the only slightly guilty) and not intending to use them immediately was happy to leave them in their sealed plastic bags as supplied. Sometime later on giving one a wiggle was surprised to find that the inner ring would not rotate. On opening the bag and applying a little more pressure I found the ring could be rotated, but I stopped after a couple of millimetres, due to the sound and feel of grit in the bearing. Further investigation – poking around in the back of the nut with a toothpick, yielded grey grease and half a pound of metal cuttings.

Now to the question of how to deal with this problem and future maintenance requirements.

A search of the internet proved rather unhelpful. My own thoughts were to clean the nut in degreasing fluid (automotive type) in my small ultrasonic cleaner. However, once clean I could find no information on what grease to pack it with (if any), how much to use and how to apply it.

Any advice that can be provided would be much appreciated.

Pero

P.S. I didn't return it to the seller due to the time that had passed since receipt and also the likelihood that a replacement would suffer the same problem.

[jimmy bParticipant @jimmyb]

I'd just return the nut, I'm sure the supplier will exchange for a good one

jim

[Bernard WrightParticipant @bernardwright25932]

I had a problem with a bearing nut, after doing a bit of turning in the lathe I found a few ballbearings on my saddle.

Not immediately realising where they had come from, went to retighten the nut but found it lumpy, then noticed the grubscrew missing from the nut, and the penny dropped.

I couldn't be sure I'd found all the bearings on the lathe, I ordered some 3mm balls off eBay.

When they arrived, filled the nut to capacity, found another grubscrew and ground the end flatish, then disfigured it a bit, to lock into the threaded hole atop the balls, as I recall just lubed it with some EP 80/90W oil.

It worked OK after that, but don't use it as much now as a plain one…

Bernard

[Thor 🇳🇴Participant @thor]

Hi Pero,

Sorry to hear about your troubles. I have a couple of ball bearing ER nuts (probably from the same supplier) and have had no trouble with mine.

I guess ordinary ball bearing grease (may be with molybdene disulphide) should be Ok for lubrication.

Thor

[Michael BriggsParticipant @michaelbriggs82422]

I had a similar problem, flushing with oil improved it a bit. Returned to the supplier who promptly replaced it with a good one. Fair to assume they would check a replacement before shipping, pity they didn't check the first one.

Michael

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