It hovers great with no WobbleOfDeath (WoD) in Stabilize, Loiter, or Alt-Hold. I had good GPS, so I took it up to about 50 ft. While I have had the Nova for about 6 months now, today's flight session was really just like number 10 or so. See last few posts for my progress on this rebuild.
In summary, the FC is now mounted using Zeal, and placed so that accelerometer/gyro chip is centrally located, and perpendicular to designated axis. Check-out these low vibrations. X/Y are -1 ~ +1 . Z is -12 ~ -8.
Also, X/Y originate at 0 and Z originates at -10 now ... which should be correct if you analyze the mid-points counts of the established Acceptable Ranges of -3/+3 and -15/-5 .
And I think these numbers (generated by calibrations) show just how close the GYRO chip is to "center" or 0.00 OFFSet. Apparently, the prime ACCelerometer CALibration number must be 1.0.
INS_ACCOFFS_X,-0.03946298
INS_ACCOFFS_Y,0.1668732
INS_ACCOFFS_Z,-0.2659737
INS_ACCSCAL_X,0.9984079
INS_ACCSCAL_Y,0.9933763
INS_ACCSCAL_Z,0.9894971
INS_GYROFFS_X,0.02348998
INS_GYROFFS_Y,-0.04615785
INS_GYROFFS_Z,-0.0190655
Finally, on my Nova PnF model ... if I examine where the FC was originally factory mounted (when I first received it), it was much closer to this now determined optimal location. It turns-out, it wasn't as randomly placed as I first thought. While not perfect, it was closer to optimal than the off-set location I originally picked for it (and used for first 10 flights). I think the fact that it was incorrectly mounted non-perpendicular is what threw me off.
I did research this in forums a while back, but ended up getting some inaccurate or maybe just un-conclusive data. This post is the result of my Winter 2015 rebuild (which starts here). I suppose I'll never know if Zeal or exact FC placement is more important than the other, but you can be sure that I plan to install any future FCs in other quads using this "hard learned" lesson and method. Man, talk about details being important. It should also be noted that excessive vibrations had nothing to do with the body/frame being cracked and repaired (that arm is no-more weaker than the rest of body).
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Thank you so much for posting all this info! My vibration logs are all over the place. 50% of the time they are within the acceptable limits, but when climbing or descending, they are a mess. I''ve balanced my generic 9443 props, but I was curious if you are using the factory props on these flights?
ReplyDeleteYes, stock CX-20 props from HobbyQuad.com. Best I can tell, the stock props are clones of genuine DJI Phantom (P330/SPN9) 8045 props that I picked-up at LHS.
DeleteHere, take a look! I've setup the Altitude on the right, and the AccX/Y/Z on the left. http://imgur.com/cL7LJIp
ReplyDeleteYes, those are breaching limits. Are you using Zeal? Is anything touching FC. Props balanced? Prop-Guards removed? Body/Frame tight?
Deletehttp://quadcopter-robotics.blogspot.com/2015/06/maintenance-procedures.html