I am replacing the bearings in one of my motors. The bearings will remain sealed and I need to know what oil to put in for long bearing life? I'd like to use turbo shaft oil but can't afford it.

I use the one John uses. Since its unavailable I think this one will be fine too https://www.acerracing.com/collections/lube-ball-bearing-cleaner/products/sin-lube-synthetic-bearing-oil 

Good a place as any to ask just how long bearings should last and how you tell you need to change them?
I have about 200 flights on a Cobra 2820/12 and it shows no problems.  Is that low/high?  Inquiring minds want to know.

Ken

Allot of that stuff is just Mobil 1 or molly grease repackaged with various dye and allot of hype I'm sure. My take is, oil is liquid enough to get out when you're climbin' and divin' but grease will stick and stay with the bearing so. how often do you want to fool with it? If you buy Boca bearings they tell you max rpm with the grease they come with, usually some ridiculous number like 50,000 rpm or something.

To tell if they need changing take them out, clean them then spin and feel for glitch and noise. For all the trouble of disassembly and how infrequent you do it, just pop in a new set of pre lubed rubber sealed bearings. 


Motorman

Maybe I will just buy 3 BasAss motors and throw them out when they start to ware.  I would still be ahead $$$. from 1 Cobra.

Ken

Looking at the Innov8tive web site I don’t see where that’s valid. BadAss motors appear to be more expensive than their Cobra counterparts. I only compared the BadAss 2814-870 to the Cobra 2814/20. The Cobra is significantly less dinero.

I don't know where on the web I saw them but they were like $11.00 or some absurd price.  Since I had no intention of buying them I just moved on.  If you checked them then I stand guilty as charged.  Point was a cheap motor is not worth the time and effort to replace bearings.

Ken

     The only reason you should need to re-lube a bearing is if it is used in a dirty environment and it gets dirty inside the seals. If that happens, on a bearing that electric motors use, if they get dirt in them, the damage would already have been done by the time you notice it. All bearings with rubber seals come with the recommended lubricant, and it is also possible to over grease a bearing and cause performance and durability issues. Use the wrong grease and too much of it on an electric motor and you cause more drag and your amp load increases. I don't fly electric but have worked in the industrial maintenance field for 40 years and have dealt with bearings of all sizes, shapes and kinds, even bearings that you DO NOT grease! It all depends on the job it's doing and how much load it gets. I wouldn't disturb a bearing on an electric motor unless you have a distinct problem, and then I would replace it with the exact same kind.  The bearing loaders and cleaners described here are for the off road car guys in which case you want to clean and re-lube them as part of regular maintenance before they get dirt in them. If you really want to get into small bearings, talk to the R/C jet turbine guys and re-builders for the straight skinny. If it holds up on a turbine engine, it will hold up on a 'lectric motor!
  Type at you later,
   Dan McEntee