Motor temperature for DJI 2212, HELP NEEDED

[Roger Ramjet]

Good day to all!

I am having a ball with my DJI F450 (NAZA + GPS) and I make a point to touch my motors after each flights. I run Hyperion 3s packs rated at 2200mAh and 5000 mAh. As it is rather difficult to precisely evaluate the motor temp by simply touching it, I purchased a laser temp gun on sale and it works excellent. My question what is the normal temp operating range for that motor and what is the value never to exceed so to speak. I suppose it would also be a good idea to to take a temp reading of every ESC as well or am I overdoing it? Thank you for the great answers I always get with this forum.

We may work too much but never fly too much!!!!
:shame:

 

[kloner]

your motors shouldn't be more than 130-140f..... esc's typically shouldn't be much over ambient. You want the motors to be making the power/heat, heat in esc's means there overloading

160-180f in motors would be too hot, problems will start. generally your gonna see the same numbers over and over till a problem starts like a prop worn from cavitation or debris or you crash and bend an adapter. I usually do it by hand and i look more for consistancy than the actual numbers and i expect to not get burned and to be able to hold my hand on it as long as i want

sometimes it just needs a couple drops of oil, other times it needs a new one when there is excessive heat in one

 

[Roger Ramjet]

Super, thank you for your quick reply! You bring up another point with respect to oil however. I thought the bearing (s??) were self seal and lub for life, guess not. I also heard that in normal conditions, the bearings are good for 1000 hours.... That is a heck of a lot of flying if you ask me!!! What do your suggest for oil, light machine oil or does it require special lub? Do you have to take the motor apart or you can lubricate through the opening on top? How do you proceed? I know, lots of question but all important for me and others I am sure!

 

[kloner]

they do but i see heat usually after double digit hours. i've always had tri-flow around so is what i've dropped in from time to time. If i'm going to the desert for the weekend and am going to fly 30-40 packs in 100+ degrees, i'll give each bearing a drop of oil. if they make heat, it usually slow or stops it all together. I'm sure any oil would work. tri flow wicks in good and doesn't build up, cleans off easily. the only motors i've had problems using oil on were Neu motors cause they use a cardboard insulation on the winding. regular old outrunners are epoxy, magnets and copper, nothing to really hurt in there. Getting too much in there makes oil across your gopro

 

[Roger Ramjet]

All right! I can fly with confidence now and I am glad to see that I have nothing to fear with motor temp 110 -115 F!!! I have one last question for you, is it better to let the motor sit for 10 mins after every flights (15 mins with 3s, 5000mAh) of now that I have an operating temp range THANKS TO YOU I can just stick another pack and GO! I would really like to put a good hour of flying without the 10 mins delay but I been afraid to damage my motors using them in a semi continous fashion. What are your thoughts on this? I fly in cold Canada and I see that you play in the DESERT!!! Wow!!!

 

[kloner]

I've always let em sit between packs. it's a good time to look it over, shake out the fingers and take a break. it's just hard on the gear, of course it's yours and all the better reason to monitor it all. fly a pack and measure it then fly another back to back and measure. is it different?

more important is letting the pack rest a few before recharging. You never want to use or charge a warm pack

 

[jes1111]

Oiling shielded or sealed bearings? One of my pet peeves!

To save me from more typing, here's something I wrote on another forum:

This is not the definitive reference on bearing maintenance, but it's the only one I can find online that is directly aimed at RC so I figured it may carry more weight in this discussion.

http://www.bocabeari...nstallation.txt

Note that the procedure is to remove the bearing from its holder, remove at least one shield, remove all the existing lubricant and then re-lubricate and replace the shield. Nowhere does it say anything about applying light oil to the outside of the shield in the hope that some of it will get inside! It concludes with a rather vague statement about oil versus grease, so I'll add some further explanation:

Grease is only oil with a thickener added (called a "soap"). The purpose of the thickener is to hold the lubricant in place. At operating temperatures, the soap releases the oil so it can do its thing and then "soaks it up" again when everything cools down. The exact choice of grease is determined by the bearing "Load Factor" and "Speed Factor". The Speed Factor is calculated by multiplying the bore diameter in mm by the rpm - so a 4mm ID bearing running at 10,000rpm (typical for this application) has a Speed Factor of 40,000: in comparative terms this is a "high speed application" and suggests the use of a high-performance lubricant. The Load Factor is more complex to calculate but one factor that immediately raises it is the presence of vibration in the application, which is obviously the case here. A high Load Factor also suggests the use of high-performance lubrication. A further consideration is temperature and here, again, our motor bearings are experiencing not only their own friction-generated heat but also the heat being generated in the motor windings. Given this "extreme operating environment" and since, in this application, we can't use a recirculating oil feed or sit the bearing in an oil bath the only viable solution is to use a "high load bearing grease". We also want the bearing to be protected at start-up, before the oil has a chance to be released from the soap - so we want to use a solid additive which "micro-coats" the friction surface - Molybdenum Disulphide.

P.S. If you live/fly in a sandy area then you could replace the stock bearings with the "contact rubber shielded" type. As the name implies, they have a rubber shield that contacts both inner and outer races to seal the interior against the ingress of dirt. The penalty is slightly higher static friction but that's what you should be using if you're worried about getting grit inside the bearings.