Tight motor (Solved)

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I just got a Phantom FC40 and before I even took it out of the box I turned each moter by hand and found the front right motor turned harder then the other three. You can also tell that it turns slower then the others on the ground and when shutting it down it stops right away with the others spooling down at the same time. It seems to fly OK but this tight motor makes me wonder whats up. It would also use more amperage to get it up to speed will it last? I don't think it's right. Any one else come across this?
 
Re: Tight motor

Yes it will use more power and no it will probably fail. Take it back to the retailer and have them check it out.
 
Re: Tight motor

I took the 4 screws out of the motor and it still turns stiff. It doesen't come to far out so that's all I can see. It flys OK and I thought maybe the motor would loosen up but it didn't, yet. I would hate for it to give out in flight. A new motor would be cheaper then sending it back to the dealer who is out of state because no one in my area carrys them so I may do that. This is certainly disappointing to say the least.
 
Took the C clip off the bottom of the motor and that loosened it up. There is a small brass collar on the shaft under the C clip so I removed it and filed it down a little and reassembled. Now it acts like the rest of the motors. See if that helps get any more time out of the battery that I was getting around 11m +. Thanks for the replys.
 
I have the same exact issue and the same motor in the same position. Is it hard getting the c clip off ? I'll need to try that.
 
I may just trying lubing it in that same area. I dont want to file it down unevenly.
 
The hard part was to get the C clip off because it was tight. I used a nail file laying on the table and just put my finger on the bushing, press down and slide it back and forth. You don't have to take off very much. Mine had a rough texture on both sides so all I did was to smooth it out. I did both sides. Didn't take long. The C clip will go on easier because of more clearance.
 
I had the same problem in the exact same motor. But, that was after my first crash. So, as a safety measure, I replaced my motor and the new replacement motor was quite tight and was showing the exact same symptoms as the OP has described. And this was with the new DJI motor!

When the motors were running, one could see that the motor in question was running slower.
It didn't affect flight, but post flight, that specific motor used to be warmer than the others.

Extensive lubrication with 10 and 20W pure silicon oil(meant for r/c shocks) didn't work

I'll try out this method.
Thanks JoatMon :)
 
sohail99 said:
Extensive lubrication with 10 and 20W pure silicon oil(meant for r/c shocks) didn't work


Thanks JoatMon :)


Silicon oil is the wrong thing to use as it gets thicker with heat (thats what they use in viscous couplings on cars).
Use a proper synthetic non-silicon oil to lubricate anything that gets hot.
 
So I did the same thing to my bushings on 2 of my motors that were stiff one more than the other. Now both are perfect !! :D
 
Not trying to hijack thread, but when you say "tight" is that 360 all the way around? I have a motor that definitely is different than other three. When I turn it, it has more resistance but I thought it was just stronger magnets around it since it seems to match up with them. It flies fine, probably making something out of nothing.
 
Stiff motors. When you tapped the props they would freely spin only half as much as the other two. A non-issue now after slightly filing down their brass bushings. :mrgreen:
 
Thanks for reply. I'll monitor my stiff one a little longer for temp difference after flight. I think it might be a breaking in issue. It appears a little better after about 35 flights.
 
I don't think I've ever heard of a brushless motor having to be broken in. If anything all 4 motors would all be similarly "stiff" then. No ?? :?
 

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