Craft Oscillation with QX100 @ 220 Grams how to correct ?

[Martib]

I did my first test flight yesterday and was able to capture some great (non fish eye) photos , however the QX100 with a weight of 220 Grams is making the craft Oscillate badly in hover, there seems to be a harmonic causing this but it gets better if you elevate quickly... Could it be the extended legs , the Gains , the prop guards ? I have the gains at 140% and the altitude @ 150%

Please let me know if you have had dynamic instability or oscillation on the craft after adding weight and if you could fix it with the gain settings.

 

[MonsieurAnon]

Re: Craft Oscillation with QX100 @ 220 Grams how to correct

Martlib; I think I've seen your name around here before. Reducing gains has a positive effect on oscillation. However it is usually better to treat the problem at the source. Your camera isn't too heavy, even with the FC-200 and prop guards, although you're certainly going to be seeing massively reduced flight times.

The problem is the rigidity of your mount. I suspect that there would be some wiggle in both the FC-200 and RX-100 mounting. Each time the aircraft corrects, it's going to cause them to wiggle, which turns in to feedback that the aircraft has to adjust for again. That's the frequency you're noticing. If you want improved flying characteristics, a rigid or purpose built dampened mount for the Sony is probably better. You don't even really need the servo and mount for the Vision camera, so it can be tacked on without the mount; just make sure it's secure.

I can't quite see from the photo, but the dampeners you're using are rated to ~100g. If the RX-100 is pulling on them, then this will further contribute. Again; get a purpose built mount or buy stronger dampeners.

 

[Martib]

Re: Craft Oscillation with QX100 @ 220 Grams how to correct

Martlib; I think I've seen your name around here before. Reducing gains has a positive effect on oscillation. However it is usually better to treat the problem at the source. Your camera isn't too heavy, even with the FC-200 and prop guards, although you're certainly going to be seeing massively reduced flight times.

The problem is the rigidity of your mount. I suspect that there would be some wiggle in both the FC-200 and RX-100 mounting. Each time the aircraft corrects, it's going to cause them to wiggle, which turns in to feedback that the aircraft has to adjust for again. That's the frequency you're noticing. If you want improved flying characteristics, a rigid or purpose built dampened mount for the Sony is probably better. You don't even really need the servo and mount for the Vision camera, so it can be tacked on without the mount; just make sure it's secure.

I can't quite see from the photo, but the dampeners you're using are rated to ~100g. If the RX-100 is pulling on them, then this will further contribute. Again; get a purpose built mount or buy stronger dampeners.

Hi Mr. Anon... Thank you and you were 100% correct.. I have stabilized the craft and it is working well and getting flight time of 20 mins !! All good... Now I have a new challenge.. that is to shoot a photo upwards from the PHantom at an angle of 45 deg... A mirror perhaps ?

 

[MonsieurAnon]

Re: Craft Oscillation with QX100 @ 220 Grams how to correct

You're probably better off fixing the camera to the top of the craft. I realise that this probably sounds difficult, but some drilled holes (after ensuring you won't damage the GPS antenna) could make it easy enough.