I was curious to see how many ppl balance their motors. I've been trying to reduce vibrations to eliminate shaky video and even with my props precisely balanced the video is beyond stabilizing in post. I'm in the process or replacing all motors and decided to balance them (using iPhone accelerometer) before installation but the process is tedious and not extremely precise.
I'm using the 880kv motors from 3DR's store, which brings up another question. Do higher quality motors need to be balanced at all? The motors I have seem to work fine and the quad flies great but are they ideal for capturing video or should I look at something more expensive that would not need to be balanced out of the box?
Thanks,
-Joey
Replies
Replacing the motors made a tremendous difference. My guess is that a prop adapter or possibly a shaft was bent or warped slightly during a crash which was causing severe shaking. I also added a real vibration damper similar to the one Pedro linked and I'm happy to report that video is great now.
Thanks for the replies. I will not worry with balancing motors in the future.
IMO, people should concentrate on effective vibration damping before they worry about extremely high quality balancing. I mean, of course things need to run smooth. But you shouldn't need to get carried away. I'm achieving perfect video without even balancing the props. I just use high quality props that are reasonably in balance to start with (APC), and good quality motors with good bearings and straight prop adaptors (iPower). I have't balanced or looked at anything.
And the reason I say this is that, even if you did a perfect dynamic balance on everything on the ground, as soon as you take it into the air, it's going to start vibrating. The reason is that just the act of flying through the air, creates aerodynamic imbalances that can cause vibration. So you still need an anti-vibration system that can cope with this. And in my experience, if you've done this, then naturally it also can deal with a minor amount of static imbalance.
Try spinning it up with the props inverted (so it pushes into the ground)....
My Tri had video issues after a while and it turns out I had a SLIGHTLY bent prop adapter.... It wasnt noticable when flying and my props and motors were balanced....
If you have a lathe I would suggest using a indicator and checking how true your motor/adapter is. If not spin it up and look to see if your prop adapter has any "wobble" in it...
Any wobble will produce "jello"....
most prop adapters are cheap aluminum that can EASILY bend even in a small crash.
Also HK prop adapters are known to run out of round... I perfer the Eflight ones, much lighter and MUCH MUCH MUCH better quality
Joey,
i don't know which camera you use, but this may be helpful for you. basically, it takes out the vibration between the copter and the camera, and pretty easy to attach.
http://www.ebay.com/itm/GoPro-Anti-Vibration-Mount-with-Video-Trans...
cheers,
This might be of interest: http://www.itsqv.com/QVW/index.php?title=How_To_-_Motor_Balancing
Jello in video (also depending on the camera) is sometimes caused by unbalanced motors, I balance motors first then props using a phone app and a by-product of all this balancing is the APM is much happier.
Edit: my motors are already mounted in my quadcopter so I just do the balancing with the phone attached to the quad and of course running one motor at a time, in my case with a separate receiver.
are you sure that vibration is caused by motors?
i never balanced any single motor on my quads, hexas, octas, planes and still was always (well, *almost* always) able to get good quality video. it has to be something massively wrong with motor to cause vibration that big that it would overcome all the dampeners you have on your camera gimbal..
thx,
jk