Bearing Maintenance: Anybody have experience with any of these products?

All our RC models have ball bearings, usually the sealed type. Sooner or later the bearings will need to be replaced to avoid failure but their life could probably be extended with some maintenance.

I looked around recently for some good to high quality bearings for some of my models and they can be downright expensive so I looked into some products that are made specifically for bearing maintenance and lubrication. I am listing a few products here that I find interesting and would like to get opinions for others on these products if you have used them and also hear about what products others use for their bearing maintenance.

Recently RPM released a new version of their Bearing Blaster (see news here and RPM product page here). The RPM bearing blaster is built to direct spray cleaners and lubricants into the sealed bearings and avoid overspray which can make a mess and waste cleaner or lubricant.
I think the RMP products looks good but seems to be mainly for lighter spray type cleaner fluids and lubricants.

Here is a video I found of the Bearing Blaster usage:



There is a products called "The Greaser" (product FAQ page here and main manufacturer page here) which looks really good to me when you want to use grease instead of oil. Here is a video I found about using The Greaser:



I think I want to use grease instead of light oil for my multirotor brushless outrunner motor bearings instead of oil. It seems to me that in most applications grease is the way to go. What say you all?

Grease is always the way to do a bearing, but oil is so easy, lol

This was interesting except for the part that said the grease that comes in your bearings is just for shipping and to prevent rust. That's totally ridiculous. Only a guy that sells bearing greasers would think something like that up.

...Tiger

Thanks for the comments, but nobody has talked about their own bearing maintenance. Does that mean that nobody is doing any bearing maintenance?

I have never done anything with my bearings, probably could do a better job at that.

I have some models that I've never done any bearing maintenance also. The ones I have it's been oil. Like you mentioned it's easy, but I don't think it's good at all. I think the bearings are looser on oil and not as smooth running.

Tiger commented on the guy in the videos comment that the bearings come with grease only for shipping and while I also agree that that comment is ill informed some of the manufacturers make claims that their bearings are lifetime lubricated which also think is nonsense.

I've read in a bunch of places that the Greaser grease device is really good. Several helicopter guys swear by it so I think it would also be good for multirotors which is where I am mostly interested in using it at this point even though my trucks certainly would benefit from it also.

When there are claims of "Lubricated for a lifetime" I have to ask what is the definition of a lifetime. The lifetime of an Ice Tea I had with my my dinner was about 6 minutes, and it did indeed stay cold for it's entire life. If a well greased microscopic bearing in a motor turning 30,000 RPM and pumping out over a horsepower lasts 6 weeks, well then it's lifetime is indeed 6 weeks and it lasted as advertised.

Advertising is great, like the organic health food that uses all natural ingredients. Asbestos and Plutonium naturally occur within the Earth in their pure form, don't really want that on my salad.

I agree grease would be the way to go over oil, but only if it is rated for the specific duty, but oil on occasion is better than nothing, and nothing at all is what I have ever put on anything I have ever owned. Which is exactly why my motor bearings blew up in mid flight one day two years ago. Ended up junking the entire motor over that.

Bearing life is normally measured in thousands of hours of operation. I've seen SKS bearings rated at 200,000 hrs. If you look at bearing life charts, the most significant variable seems to be temperature. That's not a big issue for us. For hobby stuff, I generally don't worry about anything. I'd certainly never re-grease anything. The idea of re-greasing blade holder bearings just seems dumb. They hardly move at all compared to what bearings normally do. I do keep a close eye on swash bearings on my heli, but if they don't look good, I'd just replace them. Most of the bearing failures we see in this hobby is because the bearings were crap to begin with. If a guy was super concerned about reliability, he should just put in some NSK bearings on day one and then forget about it. I agree that oil is generally not appropriate for what we do.

...Tiger

I cleaned a few of my bearings and you wouldn't believe the crud that comes out of the upper helicopter and multirotor bearings. I don't think any bearings will last 200,000 hours with the amount of grit that gets blown into them from the prop wash.

I've also noticed that I have to clean the propellers themselves every five flights, sometimes less, to get the bug debris and other junk off.

On the other hand I recognize that most air guys prefer to run inexpensive motors so replacing the bearings, especially with any name brands like Tiger mentions, probably costs more than a whole new motor so why bother with maintenance. Even the DJI motors are are "only" $24 so maybe maintaining or replacing the bearings is just a waste of time. I doubt I could get a good set of bearings for a DJI motor for less than $24. Especially something really good like ceramic.

If I look at all my different RC models, surface and air, the really expensive motors are in the surface stuff. As such I am surprised to note that the guys who've commented here are air guys.
Maybe the nature of the surface driving conditions, and the abuse those models get, the mentality is that replacing the whole motor is just a expected expense. It could also be that since the surface motors tend to get hotter and that heat ends up degrading the magnets that replacing the bearings and stator might not be a viable cost compared to a whole new motor.

I'm going to assume that since this thread has only attracted a couple participants that bearing maintenance is a non-issue and just not done by most RC modelers.