What type are they, if they are sealed, the oil wont get in regardless, and decent bearings are packed with grease, so even if you did get the oil inside you are then diluting the grease.
Lubrication
- Thread starter Carinrcl
- Start date
This is the best reason not to use oil. The sand will stick. IMO use electronics compressed air only
Ahahah... lubrication of brushless motors is one of those never-ending debates, pretty much like the resting voltage of a LiPo (after use)... so be prepared to hear all sort of opinions. Some will cite manufacturers like Scorpion to prove that oiling is necessary, others will tell you that their motors have thousands of flights and they never needed anything.
Personally I think that a drop of thin oil once in a while can be a good thing, if done carefully (most RC bearings are shielded, not truly sealed).
Personally I think that a drop of thin oil once in a while can be a good thing, if done carefully (most RC bearings are shielded, not truly sealed).
The bearing being truly sealed is what keeps the grease in. A bearing that becomes unsealed fails
Reminds me of re-assembling heli rotor heads. If you packed them the wrong way, the Centrifugal Force would throw all your grease out.
Sorry, I must have missed the first episode of "Bearings 101" on Netflix...
Apologies for the bad joke, but what you say is... well, obvious. The problem is exactly to obtain that "true seal", especially on brushless motor bearings.
Think about it... I believe the P3S outrunners are 800Kv... at 17V that's a nice 13'000 RPMs... and that's nothing compared to some EDF (Electric Ducted Fan) setups, which can go north of 60'000 RPMs. Now, imagine a bearing with an outer diameter of just a few millimeters, spinning at those insane speeds and easily reaching 70C/160F... it's not an easy job for a tiny metal shield to keep a few milligrams of grease inside, is it? Oh, and of course we want these bearings to cost less than $1, because we want the whole motor for $10.
Look at Boca Bearings... their standard stainless steel replacement bearings for the motor of my Trex 450 Pro (size in the same ballpark as a P3S motor) are $8 a piece. For ceramic, double that. And even their top-of-the-line bearing with the best rubber seal available (quote) "requires less maintenance than a typical shielded bearing". Read: they are not maintenance-free.
I'm not saying you're wrong, I'm just saying that lubrication of brushless motor bearings is a controversial topic for a reason, with lots of experienced folks having very different opinions.
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If anyone thinks they are getting sealed bearing motors on a $500 P3 ... think again. They may be shielded but sealed I can say quite assuredly they are not.
Nigel
Nigel
I appreciate the feedback no doubt cause this is how we learn. My major experiences comes from much larger bearings (automotive, industrial an tools) and when l see a spec of grease where it shouldn't be l know the sealed bearing has failed. And only then would l bring out the oil to prolong it a bit. As soon as you add oil to a surface it gonna catch anything that get on it. There's a lot of things you can oil that will work better for a MINUTE but as soon as u start you can't stop because you have to constantly lubricate the mess you made.Sorry, I must have missed the first episode of "Bearings 101" on Netflix...
Apologies for the bad joke, but what you say is... well, obvious. The problem is exactly to obtain that "true seal", especially on brushless motor bearings.
Think about it... I believe the P3S outrunners are 800Kv... at 17V that's a nice 13'000 RPMs... and that's nothing compared to some EDF (Electric Ducted Fan) setups, which can go north of 60'000 RPMs. Now, imagine a bearing with an outer diameter of just a few millimeters, spinning at those insane speeds and easily reaching 70C/160F... it's not an easy job for a tiny metal shield to keep a few milligrams of grease inside, is it? Oh, and of course we want these bearings to cost less than $1, because we want the whole motor for $10.
Look at Boca Bearings... their standard stainless steel replacement bearings for the motor of my Trex 450 Pro (size in the same ballpark as a P3S motor) are $8 a piece. For ceramic, double that. And even their top-of-the-line bearing with the best rubber seal available (quote) "requires less maintenance than a typical shielded bearing". Read: they are not maintenance-free.
I'm not saying you're wrong, I'm just saying that lubrication of brushless motor bearings is a controversial topic for a reason, with lots of experienced folks having very different opinions.
I would say , if you have no idea what bearing type is even used in these motors , you have no idea if it needs oiling or not .
I have known many mechanics that have pumped grease in many sealed bearing housings , just because there was a Zerk fitting in the Housing that was not removed or fitted with a Zerk fitting , because there was a threaded hole for it .
What I'm implying is , if we find what Bearing being used on these motor's , it would be an easy thing to determine what, if anything, it needs .
I have known many mechanics that have pumped grease in many sealed bearing housings , just because there was a Zerk fitting in the Housing that was not removed or fitted with a Zerk fitting , because there was a threaded hole for it .
What I'm implying is , if we find what Bearing being used on these motor's , it would be an easy thing to determine what, if anything, it needs .
Having removed the motors from my P3S .... I think that answers it well enough for me ...
Lub or not Lub ..... its everyones choice what they do.
Nigel
Lub or not Lub ..... its everyones choice what they do.
Nigel
I agree , its an individuals choice , but that really doesn't answer the question , do they need it or not ? You can lubricate anything , doesn't mean it needs it or will not cause some kind of harm or not . No one can answer that with out knowing what is being worked on .
What proved it to me was 'noise'.
After a number of flights - my motors had that typical 'screech' sound of dry bearings I have come to know from many other E models I have.
I lub'd the motors when I was repairing cracks in the arms and also fitting plates.
Noise is now significantly reduced and sounds sweet again.
Nigel
After a number of flights - my motors had that typical 'screech' sound of dry bearings I have come to know from many other E models I have.
I lub'd the motors when I was repairing cracks in the arms and also fitting plates.
Noise is now significantly reduced and sounds sweet again.
Nigel
Just by looking at the Motors , its doubtful there is a roller or ball bearing in there , most likely a Bushing type Bearing , may even be where the Bushing ( Bearing ) is impregnated with a lubricant , maybe a dry lubricant or some type of Oil, hard to say with out disassembling one. When I get a chance I will purchase one & pull it apart , unless someone has a bad one they are willing to send me so I can disassemble it , lol .
I used to work on equipment that had these type of bearing in them & the only way to quiet them down was to clean them with electronic cleaner , worked every time. Oiling them may actually be cleaning them .
With a Bushing type Bearing , they have a service life & in an inexpensive Brushless Motor , they are throw away type of Motor when they go bad .
I have not been able to find the manufacturer yet , only DJI #'s .
I used to work on equipment that had these type of bearing in them & the only way to quiet them down was to clean them with electronic cleaner , worked every time. Oiling them may actually be cleaning them .
With a Bushing type Bearing , they have a service life & in an inexpensive Brushless Motor , they are throw away type of Motor when they go bad .
I have not been able to find the manufacturer yet , only DJI #'s .
I appreciate the desire to contribute to a topic, but let's try to go beyond the "just by looking". I haven't opened the 2312A motors on my P3S so I won't make any assumptions, but I have yet to come across a single RC brushless motor that runs on bushings. The old 2312 were definitely on ball bearings (plenty of videos showing how to replace them, by the way), so I would be extremely surprised if the 2312A are any different in that respect. And "just by looking" at some on the online photos, they certainly seem ball bearings to me...
Now, back to the original topic. Many OEM brushless motor bearings have a simple non-contact metal shield, and these can definitely be oiled: there is always (in some bearings more than others, because of brand/model/size/tolerances) a little gap between the shield and the inner race, and a drop of thin oil carefully positioned there will eventually make its way inside (wiggling/rotating the inner race helps a lot).
Those who dismiss the subject by stating with absolute certainty "motor bearings are sealed" have clearly never tried, or maybe don't know the difference between a shield and a seal.
Whether you should oil these bearings or not, as I said, it's almost a matter of preference: some do it religiously every x flights/races/runs, others never do it. Some do it only when the bearing becomes noisy. In the same situation, some would take it as a sign that the bearings must be replaced, others would replace the entire motor (side note: it seems the new 2312A motors are much more difficult to take apart than the 2312).
Personally, I act a bit irrationally on the subject... have a couple cars, and I think I never ever oiled those inrunners. On planes... I do it only if I'm taking the motor apart for some reasons (cleaning, bent shaft, etc). Helis... I have so much appreciation for the complexity of these machines - as some of you can tell tell from my forum name - that I check and lube everything every few flights.
On the P3S, I haven't done it yet (still under warranty, I try not to touch anything that could give DJI a reason to deny a claim) but I would not hesitate a second to oil them if they start making noise. Actually, I've seen people drilling a small hole on the back of the motor arms, so they can lube the bottom bearing without taking the motor off.
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Sure. I benefit from other people's posts (yours included) so I try to give back to the community whenever I have something meaningful to add to the discussion.
You did notice I said it would be hard to tell with out disassembling one , I haven't , so my observations are just from experience from other things.
Wouldn't surprise me one way or the other , what type of bearing the Motors use. With out actually seeing one & on my goggle search on them , I never came a cross someone changing a bearing on a P3S motor , not that they are not out there , I just didn't see any , but I'll take your word on it until I look at one .
As far as oiling them , with out actually seeing one & how , if at all its sealed , its pretty much guessing . .
Hey Nigel,
I have one of the first Blade 350QX quads.
It has hundreds of flights. 2 years old and still going strong on the original motors.
Just a little light oiling occasionally.
These brushless motors can take a lot of use. With just a little maintenance & care, they should run for years
