It’s not unusual to see some rise in vibrations as you increase in speed. There’s no clipping so that’s good. That suggests things aren’t out of control.
Z means a vertical vibration so I’d look at the track of the blades to see they’re equal and that the motor mounting is good. Make sure everything is solid and square.
Long shot idea (since you’ve already replaced props): The motor graph looked good, but #3 looked consistent a bit lower than the rest. Normally not enough that I’d panic but if you’re chasing vibrations it could be a clue. It may have a twist of a couple of degrees compared to the others.
The other thing to do would be to soft mount the cube. You probably don’t have to get too carried away with gel pads. I’ve had luck with the double sided foam adhesive pads, similar to the ones that should have come with the cube. The ones I use are thinner and not as soft as the supplied ones. I got them from amazon so I can find a link if your curious.
As you suggested motor 3 had a slight twist. I have included a link below for 2 test flights. Flight 1 was with the twist removed from motor 3 and nothing else changed. Flights 2 was with a small piece of the black foam that came with the clue black placed between the frame and flight controller. I think it has improved the z axis vibration. I will do another test flight at the weekend with some speed to see if there is any difference.
Yes, that helped. Your motors are all really close now, and the vibrations in flight 2 are noticeably lower. That’s always good. Now to be fair, your vibrations in flight 1 were still perfectly acceptable, but the foam certainly improved things.
@Allister Did a few more test flights and didn’t really see a great improvement in forward flight until I looked at the data again and wondered why there was an offset in the x and y vibrations. I looked all round the copter and thought what if the battery was causing a vibration so i did a test hover with the battery on the ground and the copter powered though a rather long extension lead. results below.
Yes there is a problem ever since upgrading to 4.1 there a buzzing sound off the motors in forward flight but only in loiter mode When I posted the problem in another post its was suggested that it could be a vibration issue. The problem was not in any other previous version.
Okay, warm isn’t bad. But it’s probably a clue. I had to go back to the flight 2 log because the log for the tethered flight showed very poor tuning. Was the warm motors after the tethered flight or normally?
In flight 2, the overall tune looks good. But I think roll could be improved. Might be worth running auto tune again and seeing if that cleans things up.