The thing is that it actually flies very well! position is held well on GPS aided modes. It just vibrates in place. I am able to put it into PosHold or Loiter and feel the vibes through the landing gear.
I can see the vibrations when holding a hover. not only in the frame itself, but the GPS mast is basically getting is perfect harmonic frequency and vibrating all over.
I just feel uneasy about letting a copter go fly missions on its own with vibrations like this. Something about the harshness of these vibes bothers me.
ā¦It also bothers me that my OLD APM2.6 flies with fewer vibrations than this top-of-the-class Cubeā¦lol
S550, born for vibes. Had also many vibes with that copter because of the soft arms. There are to different types of arms available. One with and one without carbon rod in the arm. The one with carbon rod inside have small slots on the bottom side and improves vibration. Carbon propellers (well balanced) and aeronout Propeller also Improved in my case.
And your z-value is to high. The higher the weight of the fc the better is the damping effect (physics) if you use anti-vibe mount. Measured vibrations will also cause additional vibrations. You really should try to damp better perhaps with tape. I have excellent success with this: https://de.aliexpress.com/i/32839652501.html
Try to use anti-vibe. If it does not help you can remove, but you will see imporovements as I have seen.
You should also think about a different frame (i.e. Tarot 680/690), which is much more stable. You are using a quite expensive FC on a very cheap frame
Yes, I did my research prior to purchasing. I made sure to get the version with carbon rods in the arms. Purchased from Hobbyking. I am aware of its reviews, but this is the size range I was looking to build. The Tarot 680/690 is a totally different size class and power system required. I made the choice to spend my money on a high end FC rather than a frame. I realize that it is possible I am struggling with that decision at this point.
Do you know of any other, higher quality, ~550mm hex frames? I was unable to find any. I did consider cutting down the arms on a 680/690, though.
I cutted the arms of Tarot 680 down to 570 and used this motor mounts: http://s.aliexpress.com/yIBZFvqE. As ESCs I used DYS 40A and put them in the tube. FC is an CUAV Pixhack v3 and Air Gear 450 motors
another Copter I have is: http://s.aliexpress.com/7nEJvyEV, which is even better than the tarot. More stable arm mounts. Same ESC in tube and same FC and same motors
Hereās a suggestion - find the resonant frequency of your arms and props (just pluck both like a tuning fork) using iAnalyzer lite on your iphone. If either matches your peak then applying a notch may well help - the vibration will be a feedback effect, so reducing the noise should help.
a different battery plate I have that has the rubber damper rings - might allow de-coupling of battery mass from the frame
stiffening/shortening my GPS mast - IDK. Maybe the GPS vibrating/wiggling around is sending some erroneous data.
I ordered a set of Xoar PJP-N matched pair propellors, 10x4.5. Hopefully theyre more balanced and stiffer than my current props.
all are grasping at straws, but I like experimenting anyways, so im having fun.
I am reconsidering purchasing a Tarot 680pro and cutting the arms down as well, but I am not done experimenting yet. I havent thrown in the towel quite yet.
The resonant frequency of both my arms and props are somewhere between 20-30Hzā¦soā¦ Does that rule out the frame & props as a major contributor to my vibes?
There will be harmonics. So letās say its 25Hz then there will be harmonics at 50Hz and 100Hz - if your motor peak is at 100Hz then that would explain it.
You are testing my physics here, but not neccessarily I donāt think - the motor peak is at 100Hz which will then vibrate the arms at the 3rd harmonic. But this is all theoretical - I think you need to experiment a little to get more data. One other thing you could do is add some weight - this will increase the hover throttle and might stop the resonance (if that is what it is).