Bearings : ZZ vs 2RS

Both the 608ZZ and 6082RS bearings should be a good choice for the MPCNC building.
I have lot of ZZ bearings but I’m wondering if the 2RSs wouldn’t be better, because of the increased protection from dust and microparticles.

Did anyone built the MPCNC using metal shielded bearings (608ZZ)? Would that REALLY be a good choice for a milling machine?

I don’t understand the question. They are the same bearing, one just has more protection from milling debris.

Hi Vicious!

Since the ZZ shielding will not prevent small particles and dust to enter the bearing, how long will it take to stop the bearing from turning properly?
I wonder if that extra protection will bring to a better long-term performance.

I reckon theyd jam up pretty quick. Its not much more expensive to just get the rubber sealed ones. I think I paid like 30 bucks for 100 of them.

1 Like

If you don’t have dust collection, the standard bearing will clog up pretty quickly.
Mine were already in pretty bad shape after just one month of (intensive) use without dust collection, in my tiny little shop without air circulation (a particularly horrible environment).
So I strongly advise you to use shielded bearings if you can, and also to build a dust collection system ASAP

1 Like


any longterm experiences using ZZ ball bearings (instead of rubber realed RS)?

I am wondering because I accidently received ZZ bearings instead of the ordered RS bearings and have deceide if I use them or have to reorder RS bearings.



You should be okay, depending on what you do with your machine.

1 Like

hi ryan,


when milling plywood and/or acryl there are a lot debris, so am wondering if you have a real advantage when using rubber sealed bearing vs “only” metal shielded?

or do you have to replace the bearing (no matter what shield you are using) anyways after a period of time? how often?

can you tell me your experience?






Dust collection! After that, the only thing that really gets flung out is larger pieces, which shouldn’t get into the bearings. If it’s small enough to screw up your bearings, it’s small enough to breathe. Like Tom Dickson always says, “Don’t breathe that!”