Jello Question - Mini 3 Pro

4006448 · Jan 16, 2024

Looking for some sage advice please. I fly back home to Australia today having been in North Carolina on a work trip. I brought my Mini 3 Pro with me, but the wind where I've been staying has prohibited me from being comfortable putting the drone up. I did have a window of opportunity yesterday and when I went to video, I could see the Jello effect on the RC screen - the video is unusable, but I did snap a photo that came out OK.

My home area is in Qld (sub-tropical) and Dr Google indicates there are some online opinions that cold weather can cause the Jello effect. The temp yesterday when I flew was around the +3 to +4 degrees Celsius range. I've not had any Jello issues prior to this flight. The gimbal seems to move fine, and the props are in good condition too.

I'll put the drone back in the air when I get home (summer) to see if the Jello persists. Is this likely to be a Mini thing as I see many others posting in colder temps but with larger drones? Any thoughts appreciated.

slup · Jan 16, 2024

Jello is usually due to excessive vibrations generated from the drones propulsion system... or it could be from a gimbal that's not working as it should or any lose part that vibrates.

+3/4 C degrees shouldn't be any problem at all for the gimbal.

4006448 · Jan 16, 2024

slup said:
Jello is usually due to excessive vibrations generated from the drones propulsion system... or it could be from a gimbal that's not working as it should or any lose part that vibrates.

+3/4 C degrees shouldn't be any problem at all for the gimbal.

Thanks for your response. I’ll put it up when I get back home and check. Had no issues previously - but long flights to the US.

Droning on and on... · Jan 16, 2024

slup said:
Jello is usually due to excessive vibrations generated from the drones propulsion system... or it could be from a gimbal that's not working as it should or any lose part that vibrates.

+3/4 C degrees shouldn't be any problem at all for the gimbal.

Speculation, but any lubrication in the gimbal could become viscous at low enough temps to reduce performance, and be jello vulnerable.

Also, and I'm a bit more inclined to suspect this, the rubber mounts for the gimbal assembly do stiffen in cold weather, and it wouldn't surprise me if there is a temp at which this becomes a real issue transmitting excess motor vibration.

Those rubber dampeners are there for a reason

4006448 · Jan 16, 2024

The rubber is what I suspect as the cause. Just wondered what else to consider. Thanks!

slup · Jan 16, 2024

4006448 said:
...I’ll put it up when I get back home and check.

Look out for anything that can indicate any kind of unbalance in any of the motors... First visual by checking for any smaller dents in the motor bells & look at the gap between the bell magnets & stator posts when rotating by hand.
Then take off the props & idle the motors & feel out the motor shafts. If nothing so far have indicated any balance issues get the drone airborne, hover it slightly above head height... there carefully feel out every leg for vibrations worse than the others.

Above all this check so all screws are tight around the drone, feel out the legs for any abnormal play & do this also with the gimbal attachment, but gently.

EssenYVR · Jan 17, 2024

slup said:
Look out for anything that can indicate any kind of unbalance in any of the motors... First visual by checking for any smaller dents in the motor bells & look at the gap between the bell magnets & stator posts when rotating by hand.

I would think that a good place to start is to launch the drone up to a height of 4-5 feet (around 1.5 metres) above the ground so that you can grab it with your hand as you would in a hand landing. Any undue vibration from the propulsion system would likely be noticeable through your fingers holding the body of the drone.

SmilingOgre · Jan 18, 2024

I only know the "jello" effect as a rolling shutter effect while panning rapidly. It would be nice to see what you are calling "Jello".

4006448 · Jan 19, 2024

I’ve just got home after 2 days of

and airports. I’ll look at getting the raw video off over the weekend to post.

slup · Jan 19, 2024

SmilingOgre said:
I only know the "jello" effect as a rolling shutter effect while panning rapidly. It would be nice to see what you are calling "Jello".

I assumed it looked like this...

4006448 · Jan 19, 2024

I'm back home and checked the propellers and motors as suggested here and I'm no genius or engineer, but everything seemed OK, so I started up and put the drone up for just a quick check. NO jello - in this video, I've just put the original (unedited) video of the jello experience, a still image I took when the video was experiencing jello and a short video today with no jello.

EssenYVR · Jan 19, 2024

4006448 said:
I'm back home and checked the propellers and motors as suggested here and I'm no genius or engineer, but everything seemed OK, so I started up and put the drone up for just a quick check. NO jello...

There may have been some sort of temporary imbalance in the props. A classic way for this to happen is icing conditions where one blade gets more ice than another, or perhaps some ice gets thrown off one blade but not another.

The insidious thing about icing is that all the evidence disappears (by melting) when the drone returns to warmer air.

4006448 · Jan 19, 2024

EssenYVR said:
There may have been some sort of temporary imbalance in the props. A classic way for this to happen is icing conditions where one blade gets more ice than another, or perhaps some ice gets thrown off one blade but not another.

The insidious thing about icing is that all the evidence disappears (by melting) when the drone returns to warmer air.

Could it be that I took the drone out of a nice warm car and then had it flying within a few minutes with a reasonable temperature difference? If so, I should give some time to acclimatise before flying next time?

EssenYVR · Jan 20, 2024

4006448 said:
Could it be that I took the drone out of a nice warm car and then had it flying within a few minutes with a reasonable temperature difference? If so, I should give some time to acclimatise before flying next time?

If anything, warmer props would resist icing rather than encourage it. But the props have very low mass and so I think they'd reach thermal equilibrium with the air pretty quickly. I don't think there's any particular need to wait.

I'm not saying that icing is the cause of your jello - icing usually occurs when there's visible supercooled water (mist, clouds) in the air, and that doesn't seem to be obviously visible in your video. I'm just using icing as an example of how props can get temporarily unbalanced.

If everything is working smoothly now then I think you may have to chalk it up to "just one of those things" unless there's some sort of evidence on the prop blades that something may have been stuck to one of them.

I suppose another potential cause of an out-of-balance situation could be if one of the prop blades wasn't able to freely swing out to it's fully extended position. So it might be worth checking that each of the blades pivots freely around it's attachment point (the screw that holds the blade on). Note that this is not the same thing as the motor shafts turning freely.