Can someone confirm that the cogging of the motors is down to the magnets and not the bearings?
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When to replace motors?
- Thread starter JonW
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What kind of oil do you recommend? I'm new to this and don't really know what brands of lubricants are trusted or not. Ask me about CV boots on an fj cruiser however....
I believe that the person using penetrating oil will actually cause bearing failure rather than prolong the life of the bearings by washing out the original lubricant and will be running on just penetrating oil.
Some R/c helicopter pilots oil their bearings every few flights and they say it really helps bearing life. One thing about oiling bearings is that once you start oiling you must continue on a regular basis as the original lube will have been washed away.
You have to consider the motors as a part that requires replacement. Yes you can replace the bearings but in my opinion it is not cost effective.
Some simple tests to perform are to feel the motors after flight and smell the vent holes on the fuselage for any burning smell from overheating of the electronic speed controller.
When a bearing fails it causes extra drag on the motor and the quad will provide more current to that motor to keep craft level.
This will cause the motor to get hot and also cause extra heat to be generated by esc and can cause it to fail.
Some R/c helicopter pilots oil their bearings every few flights and they say it really helps bearing life. One thing about oiling bearings is that once you start oiling you must continue on a regular basis as the original lube will have been washed away.
You have to consider the motors as a part that requires replacement. Yes you can replace the bearings but in my opinion it is not cost effective.
Some simple tests to perform are to feel the motors after flight and smell the vent holes on the fuselage for any burning smell from overheating of the electronic speed controller.
When a bearing fails it causes extra drag on the motor and the quad will provide more current to that motor to keep craft level.
This will cause the motor to get hot and also cause extra heat to be generated by esc and can cause it to fail.
I asked the guy with AVID about the use of oil or grease, as he offered both, and he said it's a personal preference to which. The oil he offers is very light, almost like a pneumatic tool oil or possibly a mineral oil. "Machine" oil is another very lite oil and is purposed much the same. The recommendation from Avid is based on his market, RC cars, which he says runs at a higher RPM than our MR motors. Further they are playing in the dirt, so his recommendation was a hard use case.
@RolandS888 recommends the Tri-Flow material, which I have limited experience with. It has Teflon so it does add material to smooth the races. I've only heard good things about Tri-Flow over the years.
I'm old school tech, machine oil...
I'm a believer if you don't lubricate bearings, they will fail. These aren't sealed units and will get dust and moisture. Small amounts of moisture and you're flushing out the bearings from the original lubricant. Heat alone will break down the factory lubricant and shorten the life. So to say I'm flushing out the bearings by adding oil is kinda funny to me. Google lubricating small electric motor bearings and decide yourself. And yes I do oil every couple hours of flight.
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Dont assume that bearings this size are always lubed from new. They can be bought dry, and i have no idea what 3DR use in these Sunny-T motors.
You referred to "penetrating oil" previously, which is different than just oil. @robertsmihte was just saying penetrating oil will flush rather than lube...which he would be correct.
FWIW, picture of AVID's syringe type oil applicator, as an example only. This type allows you to place whatever oil into the container.
I found the time this afternoon to remove my motor pods and oil both the top and bottom bearings.
I used the stuff that @RolandS888 recommended. Found it here in Australia at Cell Bikes.
After putting Solo back together and taking her out for an few laps up the beach I think there is certainly an improvement. I really noticed the difference in the sound of the motors when starting her up.
Well worth the AUD$19 it cost me. Thanks @RolandS888 for the advice and recommendation.
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I used the stuff that @RolandS888 recommended. Found it here in Australia at Cell Bikes.
After putting Solo back together and taking her out for an few laps up the beach I think there is certainly an improvement. I really noticed the difference in the sound of the motors when starting her up.
Well worth the AUD$19 it cost me. Thanks @RolandS888 for the advice and recommendation.
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Here's a motor teardown video posted last year if anyone has an interest. Beware the music may cause insanity after about 30 seconds.
Having rebuilt about 20 DJI Phantom motors over the years which is a bit easier without the ESC attached I tended to see failure rates around 70 hours flying in dusty/hot Arizona.
I found if I used a cheap IR thermometer and measured the motor temps from time to time I could pretty much tell what motor was going to fail next by looking for a spike. Generally speaking I stop flying a bit when the motors reach 145F which happens pretty frequently in the desert. These were selling for about $13 a few years back on EBay.
Amazon.com: RioRand(TM) Non-Contact One-Handed Infrared IR Laser Digital Thermometer: Patio, Lawn & Garden
I will be stunned if these 3DR motors get 150 hours in high heat environments. Maybe Iceland or Alaska,,,,,,,,,,,,,,,,,
Having rebuilt about 20 DJI Phantom motors over the years which is a bit easier without the ESC attached I tended to see failure rates around 70 hours flying in dusty/hot Arizona.
I found if I used a cheap IR thermometer and measured the motor temps from time to time I could pretty much tell what motor was going to fail next by looking for a spike. Generally speaking I stop flying a bit when the motors reach 145F which happens pretty frequently in the desert. These were selling for about $13 a few years back on EBay.
Amazon.com: RioRand(TM) Non-Contact One-Handed Infrared IR Laser Digital Thermometer: Patio, Lawn & Garden
I will be stunned if these 3DR motors get 150 hours in high heat environments. Maybe Iceland or Alaska,,,,,,,,,,,,,,,,,
Well, they really don't tell you anything about the oil. What's in it that makes it so valuable.
$9.99/ 12cc = about $25/ oz, $787/ qt, $3,151/ gal.
When I was restoring military vehicles I did a lot of research on oil & grease and sent a lot of oil samples to a lab for analysis.
What I learned was there's not a lot of difference between lubricating oils aside from viscosity and additives.
How do you know they're not just putting air tool oil or something else in the syringe? Huge profit margin in doing that!
I'm not making any accusations- I just want to know what I'm buying, especially when it's expensive.
Lubricants like Tri-Flow have proven track records- why not go that route?
I suppose it made sense to trust a bearing manufacturer that has a decent reputation in a niche market, designed specifically for high speed applications. Personally, I'm less concerned about cost, while putting my trust in outfits that have a lot of expertise. To each their own
Boca bearings have this in a Multi Rotor Maintenance Kit
MULTI ROTOR MAINTENANCE KIT
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MULTI ROTOR MAINTENANCE KIT
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I have been in car repair business for years. Plenty of good leads here.
Oil can be anything depending on the additives and company keeps their secrets. For us consumer we should focus on the results others are sharing about the good oil for our application.
Penatring is usually not a long term lubricant. In Canada we have Wd40 which in my book is about the same as soapy water. The more fluid it is the more it will penetrated.
Typically bearing spinning over 6000 rpm will survive with good lubrification. Penatring oil was not designed for this. So if used it would have washed away the good lubricant, will not be sufficient lubrification and will not stay in very long but better than nothing if the bearing was dry to start.
The questions are
1- How to get the oil to the race of the bearing?
2- what lubricant should we use?3- How often?
4- What is the safe life expectancy of bearing? Or complete motors?
5- How to identify a problem motor before it fails.
Most of those questions have answers here, thanks every one for sharing. Any point above not fully manage will lead to unpredictable failures.
I'm preparing for transport Canada uav accreditation. Risk management is crucial to get permission to fly. Being a quadcopter single motor failure = flying brick.
Oil can be anything depending on the additives and company keeps their secrets. For us consumer we should focus on the results others are sharing about the good oil for our application.
Penatring is usually not a long term lubricant. In Canada we have Wd40 which in my book is about the same as soapy water. The more fluid it is the more it will penetrated.
Typically bearing spinning over 6000 rpm will survive with good lubrification. Penatring oil was not designed for this. So if used it would have washed away the good lubricant, will not be sufficient lubrification and will not stay in very long but better than nothing if the bearing was dry to start.
The questions are
1- How to get the oil to the race of the bearing?
2- what lubricant should we use?3- How often?
4- What is the safe life expectancy of bearing? Or complete motors?
5- How to identify a problem motor before it fails.
Most of those questions have answers here, thanks every one for sharing. Any point above not fully manage will lead to unpredictable failures.
I'm preparing for transport Canada uav accreditation. Risk management is crucial to get permission to fly. Being a quadcopter single motor failure = flying brick.
