Lubrication..every 6 flights?

Posted by Dan McKenna on February 26, 2015 at 10:17pm

I seem to remember a discussion about the need to oil the motor bearings every 6th flight.

OMG!

I was on the phone with 3DR about another subject and when finished I said  "oh by the way"

blah, blah, need to Lube? and the answer was yes, I will send you the directions. 

I did not receive the information as of 2 weeks later.

How often to do oil the bearings?

with what oil?

and how?

Decades ago I built anemometers for a research project and calibrated them in a wind tunnel. I found that

it was better to run the bearings dry as it did not collect dirt as well. The bearings were very lightly loaded

so it seemed to work. It seems to me that when I fly and apply vigorous attitude adjustments the bearings are sufficiently loaded to require Lubrication.

Can I get a witness?

How about, how often and the technique.

Safe landings

Dan

 

You need to be a member of diydrones to add comments!

Join diydrones

Email me when people reply –
Follow

Replies

    • Gary McCray > Cala March 1, 2015 at 2:52pm

      Sorry I wasn't clear, possibly I misunderstood what you were saying.

      Conrad style pressed ball bearings are what are used in all the brushless electric motors that are available to us from all manufacturers.

      These can either be shielded or sealed or not.

      Sealed bearings have side wipers / seals on them and these can be either plastic/rubber or stainless steel.

      If you look at both sides of the bearings and it appears to be closed by a plastic or steel ring and you cant see the individual bearing balls at all, it is a sealed or shielded bearing.

      These bearings are prelubricated but many of them can benefit from adding a little high quality oil or grease to the shield area which can "wick" into the bearings.

      Here is a picture of some very high quality ABEC-7 style Conrad style sealed ball bearings for a top quality KDE motor:

      3702551668?profile=original

      and some Tiger motor shielded bearings:

      3702551561?profile=original

      Tiger Motor and KDE and other motor manufacturers use shielded and sealed bearings which are designed to be used and then replaced.

      However because of the shielding and the use of a top quality lubricant they out last unshielded ones even if you don't relubricate them at all.

      Sealed bearings are designed to be used for the life of the bearing without any relubrication.

      Generally shielded bearings can accept additional lubrication around the shield with it wicking into the bearing.

      Sealed bearings are less likely to be re-lubricatable by this method.

      In practice, you will probably not be able to determine whether you have a sealed or a shielded bearing so it is best to treat it as shielded and add a bit of lubricant to the seal/shield area once or twice a year (more under use in severe weather or dust conditions).

      Some of the cheapest Chinese motors that we use have ABEC style open ball bearings which do not have side seals at all (open bearing)

      These definitely can and need to be relubricated (and even cleaned if necessary prior to relubrication).

      These are still a Conrad style pressed bearing but they do not have side seals and so are open for relubrication.

      For small, high speed electric motors (like our brushless ones) synthetic oils/greases containing PTFE additives will generally provide the longest smoothest operation with the least bearing wear.

      Big heavily loaded applications like automobiles, trucks and heavy equipment require higher film strength, but for our little high speed motors, film strength is not so important as having a wide load operating range.

      Basically with the normal shielded ball bearings an occasional (once or twice a year) application of a small bit of lubricant to the shields themselves is a good idea and for unshielded bearings bimonthly cleaning and relubrication is probably a good idea under moderate use.

      (The effectiveness of lubrication will vary for shielded / sealed bearings, some are simply so well sealed that no lubricant will seep into the bearing.)

      Hope this helps, this is a matter of considerable contention, but this is the best I have been able to make of it over the past 5 years.

      Best Regards,

      Gary

      KDE72XF-BRK_efb665ab-6693-4d41-b80a-f8d505efdc35_grande.JPG

    • Cala > Gary McCray March 1, 2015 at 5:19pm

      I find this Super Lube here, it's correct?

      (second one)  https://www.deere.com.ar/es_AR/parts/featured_parts/general_use/lub...

    • Gary McCray > Cala March 2, 2015 at 4:54pm

      Hi Cala,

      Yes that is SuperLube (oil) labeled for distribution by John Deere.

      And their spray should work fine, although what I might do is spray a bit on a Q-tip and rub it on the bearing rater than just squirting it into the motor.

      I use the light Superlube grease myself dabbed on the bearing with a toothpick.

      3702779748?profile=original

      but the spray should work fine, this really is great stuff.

      Best,

      Gary

    • Cala > Gary McCray March 2, 2015 at 5:05pm

      Thank's Gary, perhaps I can find that one here, I read about It and looks interesting for many uses

    • Cala > Gary McCray March 1, 2015 at 3:07pm

      Thank's Gary to this complete explanation, I'm in the correct way with incorrect grease, I'm going to find you recomended one.

  • Cala February 28, 2015 at 3:24pm

    http://diydrones.com/forum/topics/vibration-isolation-and-dampening... Look here

    • Dan McKenna > Cala February 28, 2015 at 3:46pm

      Thank you!!!

      If the stuff on the bottom is removed with liquid....

      it is not magnetic because it would stick and be difficult to get off....

      Do you agree?

      I saw the magnets...are the bearings are covered with the same colored stuff?

      D.

    • Cala > Dan McKenna February 28, 2015 at 4:33pm

      Not only liquid (alcohol or contacmatic I used a wood toothpick and a clean ear to help remove the stuff it's give me some work;  it was like a dirty heavy grease, that let me think that bearings loose grease but I didn't have or find quickly new ones so I decide to try this and they are working yet :) (aprox tree years). 

    • Dan McKenna > Cala February 28, 2015 at 5:15pm

      Great!

      3 years, once per year maintenance.

      How often do you fly?

    • Cala > Dan McKenna February 28, 2015 at 5:53pm

      Don't take as a scientific recip, it's only what I do now before aprox  two years flying the copter and find that problem when I was curious to see how the motors are inside after a time flying, it's the first post that I read about lubricating the bearings, I noticed them little crispy and decide to do that.

      It's variable my flying time, I fly more often in spring and summer monitoring crops and sometimes weekends, perhaps two hours a week in average aprox but I don't have stadistics. Perhaps it's a good work to do in winter when cool weathers come and flying times are less, I'm in summer now, I'm going to re-check them this winter, perhaps it's a good practice too to put a little drop more often but I don't shure how that practice works with dust, oil outside the bearings go to magnets I think and helps soil to stick to them and give another problems (imbalance, etc.) any experiences with this practice?.

This reply was deleted.