Quadcopter ascends about 20 feet then starts to wobble

[emansfield]

I have a home built Spyda500 quadcopter with an omnibus F4 V3 flight controller. When the drone takes off in a straight vertical ascent it rises smoothly for about 20 feet (i.e. 2 or 3 seconds) but it then starts to 'wobble' uncontrollably (i.e. oscillates by rolling from side to side quite violently.) All the flight controls seem to work smoothly in test mode (i.e. without props.)
Does anyone have any idea why this might be happening?

 

[wafflejock]

I have a home built Spyda500 quadcopter with an omnibus F4 V3 flight controller. When the drone takes off in a straight vertical ascent it rises smoothly for about 20 feet (i.e. 2 or 3 seconds) but it then starts to 'wobble' uncontrollably (i.e. oscillates by rolling from side to side quite violently.) All the flight controls seem to work smoothly in test mode (i.e. without props.)
Does anyone have any idea why this might be happening?

If can share black box logs and/or video can often be helpful in catching someone's eye on what could be going wrong. In general oscillations are a sign of some PID tuning that is out of whack and/or the mounting of FC is too soft or too stiff (can cause problems either way). You want FC to move with entire quad frame but not "feel" all the vibrations of the motors in the gyro on the FC... I think "soft mount" is best option where using rubber grommets on the PCBs and screws through the quad frame to hold them on and dampen out the vibrations with the rubber. You may be able to get around it by adjusting the sliders or other PID parameters though but just guessing without more detailed logs etc.

 

[Dugdog47]

Could also be unbalanced props.

 

[LoneRCRanger]

Or the Devil's in the wind. Or probably not. Wafflejock is good advice so is Dugdog47,. Mine is never plausible. I'm the Devil's Advocate.