I have had no end of trouble with the 880Kv motors from jDrones, these past few months, and want to know if anyone else is having similar issues. I would not normally bring up a topic on a particular supplier part but these are one of the recommended motors for the DIY Arudcopter. I have now had 3 separate motor orders and each time I am lucky if I get one good motor. So far I have ordered 10 motors and have 5 unusable with the following problems:
1. One Motor burnt out on first power up after roughly 1 minute of operation. Inspection showed the motor casing had metal burs left over after machining. I fact I have found a few like this.
2. 3 motors are making a louder grinding noise due to premature bearing failure / tolerance issues. I got roughly 2-3 flights out of these motors.
3. One motor out of the last batch (arrived last week) has been tapped twice on the motor shaft which came loose on a third flight damaging my copter. I had noticed on the first test the motor was vibrating more than the others (without props fitted). After the minor crash today I found the motor when manufactured had a cross-threaded grub screw which was not able to hold the center shaft.
I have attached a couple of photos below of the latest motor because having two tapped holes on one side of the shaft leads to imbalance. You might want to check if you have one of these faulty motors.
Perhaps the DIY store needs to look for another supplier of the 880Kv motors? There have been some posts on the 880Kv motor recently. New bearings were mentioned being used in new motor batches.
It would be nice to have more than 2 flights before having to replace motors
Thanks for the update on this. I assume you've brought this to Jdrones' attention? Most people use the smaller 850 motors, which seem to be fine (I've heard no reports of problems), but I hope you've shared this with them.
The DIY Drones store sources its own motors, although they look similar. No issues so far there.
Hi Greg! If I understand you correct, you are building a new hexacopter to avoid disaster if one motor fails. To get redundancy you need a Y6 or octocopter(8 motors). From what I have read, a hexacopter will not be able to stabilize itself in the event of a motor/esc failure. I'm planning to build a Y6 instead of hexa, because these are redundant. Please correct me if I'm wrong.
Shesh, and I thought I had rotten luck. Hope you have better success.
Hi Greg ; Im a 100% new to this and i only know those 880kv motors on my HEXA, from jdrones; I've got what i think is a quite real fresh batch (end of august)
Also, i wanted to send you some good vibes, and some good echos from these; Can't be possible i took them all ;)
Until now, i've flown around 10x 10-12 minutes like a newbie (thottle up and down like a drunk monkey)
Esc warm a bit, lipo ok, motors a bit hot to my taste after a 10min run but as i don't have any previous experience with any rc motors and im not sure my props are 100% correctly balanced , i can't say if its not good ; But at least they made it until here;
I notice from time to time, i can hear a bit more "motor crunching" , but not always ; I hope its just a question of using them a bit to get them to their final mechanically constrained configuration and being sure its correctly leveled and Cog'd each time
Good to know your getting more flight time out of the 880Kv motors. I should have built a hexa to start with to cope with the odd motor problem Like you I just received a fresh batch (Early Sept).
I have used two out of the 4 new ones I purchased last month. One is ok the other is the one in the photo with a two holes drilled and tapped on the top of the motor. I have the other two in reserve.
I have my arducopter quad fixed again today. I definitely advise balancing the props and watching out for the alloy prop mounts that come with the 880Kv's motors. There not that well made. Some have oval rather than round holes where the prop shaft goes through the main body. I bought some others that look identical to the ones you get with the 880Kv's and these are off a higher quality alloy and machining. Any vibration you can remove helps with stabilizing the copter.
I am planing to switch motors soon to AXi's once their manufacturing picks up. There in short supply at the moment. Also I am determined to get a few flights out of the 880Kv's and learn more about tuning the software before going more experimental.
I would love to know what that motor clicking / crunching is on the 880Kv's. I hear this again and again despite replacing the motors. The QA issues with these motors is a concern. I found another interesting problem last night on one of the new bunch motors which I suspect is in the others to a lesser degree. The coating on the armature is inconsistent and I found two hard lumps sticking out which has been catching on the magnets in the outer spinning casing. Some other motors I have found loose pieces of metal left over from the machining process. The worst example was a 3mm round chunk in the armature wiring just waiting to short something out.
I believe the metal chucnk came from when the lower motor mount holes were drilled. Its common and you need to debur the holes drilled in alloy. In mass produced motors like these there are bound to be some which are not cleaned up properly before wiring is completed.
Thank you for the encouraging news on the motors you have been testing.
Are the motors in the picture above re-branded rc-timer motors?
James I really do not know. They are the 880Kv motors sold by jDrones This company have their own OEM motor supplier.
Well guys I must be having some bad luck this month or there is some quality issues with the latest batch of 880Kv motors from jDrones. I had another one of the new motors I just put in my quad feel like it was seizing up after a good flight on 2.0.45. I removed the motor today and found a similar problem to my last post in that the shaft has moved. This time it causd the "C" clip to rub against the motor mount. I checked my ast two new motors this afternoon and one is catching on something inside the motor (have not even powered this up yet) and the other which I have installed in my arducopter. the shaft grub screw was not tight on the shaft.
I have sent a detailed report off to JDrones earlier this week. With some more photos. So just in case you have some new 880Kv's recently, might be worth checking the small grub screw holding the shaft is tight :-)
@colbym, They are very similar to these: