My Omni Faceting Machine shipped with NSK 6202VV bearings. These bearings are deep-groove ball bearings with double rubber seals – one on each side. However they are “non-contact” seals, meaning that the rubber does not touch the inner ring of the bearing.
What this means is that when the Splash Pan floods (remember, you’ve got less than 1/8″ of clearance from the drain hole to the top of your bearings) water can flow between the seal and the inner ring. This water will be carrying all sorts of diamond and gem dust into the bearing, which will quickly reduce it to junk and start vibrating and making noise.
Non-contact sealed bearings are used to prevent dust from entering the bearing, not liquids. In this case the wrong type of sealed bearing was used.
A proper bearing would be the NSK 6202DDU – it’s the same bearing with double CONTACT seals. These seals touch both the inner and outer rings, providing an effective barrier to liquids. This will prevent the bearings from getting junked if they get a bit of swarf and water splashed onto them.
Using proper bearings would reduce the likelihood of bearing damage due to accidental flooding. But the real problem is that the Omni Faceting Machine has a serious design flaw with its Splash Pan and Spindle Housing encourages flooding, and until that is resolved there will probably continue to be problems with swarf destroying bearings.
A set of 2 NSK 6202DDU bearings should not cost you more than $10 and likely much less. When you consider how little money could prevent such serious problems, you wonder why it wasn’t done properly in the first place.
If you can’t find the exact NSK 6202DDU bearing, ask for 35 OD x 15 ID x 11 H metric bearings with double contact seals.
I have not had to change my bearings, but if anyone has done this and can supply pictures, I’d be happy to post the process.