Hot motors on 6-inch drone build

Hi there! My brother and I finished our first quadcopter drones together a couple months ago, and after some tinkering I got my 5-inch quad to work without any major issues.

My brother’s 6-inch quad flies alright, but after the first several test flights the motors have been getting really hot. On the first flight all motors were almost too hot to hold (60s flight). Two motors are now fine after tightening a loose propeller and tightening the battery strap. However, the front-left motor and the back-right motor are still getting really hot (too hot to touch) even after very short flights.

Why could this be happening? What sort of diagnostics could we run to figure this out? There is plenty of clearance between the screws and the winding, and all screws seem to be tightened as they should be. The only noticeable potential issue I have noticed is that the front-left motor doesn’t seem to magnetically snap into place as much as the other motors. Could this indicate an issue with that motor?

Edit: I haven’t touched any PID settings yet, the 5-inch and 6-inch models should both have the same settings.

Thanks for the help!

couple of things you can try

flash betaflight 4.1 and use dynamic filters
If that doesn’t help lower D gains on Pitch and Roll by 10

also do you have any blackbox logs ?

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Thanks for the response!

My brother is gone for a few days, but when we fly next I’ll be sure to see if dynamic filtering solves the issue. We are both running F7 flight controllers so I don’t think there really is any reason not to use dynamic filters. (Am I correct about this?)

I’m also planning on soft-mounting his FC before the next flight too, hopefully that will make a difference.

We haven’t done any blackbox setup yet, so sadly I can’t provide any such information at this time.

You need to soft mount the fc and make sure the screws are just nipped up don’t squash the silicon soft mounts or it will defeat the purpose.
And yes f7 will run perfectly on rpm filtering and make sure the motor screws are not touching the windings of the motors or you will get :fire: