DJI F450 Vibrations

[capglider]

Hi all,
Looking for some help on a serious vibrations issue.

So far I flew my F450 (complete stock setup) with a 3S 5000mah and gopro mounted directly to the frame (no gimbal). This went fine: no vibrations, enough power for my kind of flying, but somewhat short flying times (12min).

Today I tested two new configurations:
1) same 3S 5000mah main battery, but gopro WITH gimbal and it's own small 3S 400mah battery :
- no vibrations
- hard to keep copter hovering with throttle in neutral position (weight, I suppose)

2) 4S 5200mah main lipo (80 grams heavier compared to lipo used in test 1), gopro with gimbal and own small lipo as in 1:
- clearly much more power
- heavy vibrations !!!!!

What is the issue here ? I read stuff about prop size and/or prop stiffness. Do I need to switch to graupner props ? If so: which size is best for my setup ? Or should I start with a decent balancing of my stock props ?

 

[Rotorfreek]

I'd say your more likely got a gain issue. 3s to 4s normally needs a reduction in main pitch and roll gains of 20% or so.

Put it on a free channel and put both roll and pitch gains on th he x1 channel. Drop it in flight and see what happens...

Sent by my thumb, a trusty slave to my crazy mind. The above is the ramblings of a lunatic, and should be treated as such. Terms and conditions apply.

 

[capglider]

I'd say your more likely got a gain issue. 3s to 4s normally needs a reduction in main pitch and roll gains of 20% or so.

Put it on a free channel and put both roll and pitch gains on th he x1 channel. Drop it in flight and see what happens...

Sent by my thumb, a trusty slave to my crazy mind. The above is the ramblings of a lunatic, and should be treated as such. Terms and conditions apply.

Will do !
Just for my reference and understanding: can you briefly explain how these gains, combined with lipo type, influence vibrations ?
Thx

 

[eskil23]

Are you using 2212 920kv motors?
10" props and 4S batteries are beyond the specs for 2212 (an probably for the E300 ECS too). Some people say they use that combination and it works just fine, but if you run into trouble when going from 3S to 4S, I would keep it in mind. Have you tried if the vibrations go away if you use smaller props?

 

[capglider]

Are you using 2212 920kv motors?
10" props and 4S batteries are beyond the specs for 2212 (an probably for the E300 ECS too). Some people say they use that combination and it works just fine, but if you run into trouble when going from 3S to 4S, I would keep it in mind. Have you tried if the vibrations go away if you use smaller props?

Yes, this is the (stock) engine and ESC used, as stated above. I have not tested with smaller props yet, since that is one of the questions I have: do I need to ?

 

[Tahoe Ed]

The F450 will fly on 4S with the 10x3.8 props. More pitch than that and you will have to move down in prop size.

 

[capglider]

Hi all,
Yesterday I did some tests with lower gain values. All vibrations have disapeared ! All I need to do now is to test the flight times with this new battery and new settings.