Violent Shaking after custom mods, PLEASE HELP! (With Pics)

[JKith-Flight]

Aloha All,

I had a perfectly good working Phantom. Then I decided to upgrade from Zenmuse 2-axis to a 3-axis Gimbal. After the installation, the phantom shakes violently (you can actually see the shell shake).

All i did was remove Zenmuse, Install Gimbal Circuit board in battery compartment and attach a 2 battery holder. I did an advanced calibration, as well as compass calibration but still strong shaking. I don't know where to being to diagnose the problem.

If anyone here is able to help me it would be a HUGE help,....Thanks. (pictures attached)

 

[syotr]

Re: Violent Shaking after custom mods, PLEASE HELP! (With Pi

Two things to check:
1. In the assistant software, make sure you have selected Quadrotor X.
2. Make sure you attached the top half of the shell in the correct orientation. It is easy to get it turned 90 degrees, then you are installing the props on the wrong motors based on the direction arrows on the top.
Did it actually fly?

 

[OI Photography]

Re: Violent Shaking after custom mods, PLEASE HELP! (With Pi

and attach a 2 battery holder

I bet if you get rid of that, your problem will magically disappear.

You're probably having this issue for one of two issues (or both):

-The positioning of those battery mounts is sub-optimal, and can have a negative impact on both balance and lift.

-The weight of those two batts plus the gimbal (...plus the electronics...) is probably pushing you above the limit at which the Phantom will remain consistently stable. Do you know what the total weight is, when fully loaded for flight (incl batts)?

I don't think I've ever seen that gimbal before, so I have no idea what it weighs. Also, are those the 8" or 9" carbon fiber props?

 

[JKith-Flight]

Re: Violent Shaking after custom mods, PLEASE HELP! (With Pi

@syotr
Check All Good -

1. In the assistant software, make sure you have selected Quadrotor X.

Check All Good -

Make sure you attached the top half of the shell in the correct orientation. It is easy to get it turned 90 degrees, then you are installing the props on the wrong motors based on the direction arrows on the top.

Yes it does fly. The input response is good. It just shakes very bad, even in hover. As soon as it takes off it's smooth though, then 10sec into the flight "Shakes".

@OI Photography

I bet if you get rid of that, your problem will magically disappear.

While i will try this, I've been using this type of 2 battery setup on my other phantom and never had any problems.

The weight of those two batts plus the gimbal (...plus the electronics...) is probably pushing you above the limit at which the Phantom will remain consistently stable. Do you know what the total weight is, when fully loaded for flight (incl batts)?

(Keep in mind I have the Anti-Gravity T-Motor Upgrade) The weight of the phantom with everything is 1490grams. This is the MC6500GoPro-BLG 3-Axis Gimbal and weights 288g without GoPro Camera.

Also these are 8" Carbon Fiber Props.

Thanks for the quick response.

 

[OI Photography]

Re: Violent Shaking after custom mods, PLEASE HELP! (With Pi

Was the other Phantom you used the dual batt trays on also as loaded as this one?

Nearly 1500g is very fat for a Phantom, especially with 8" props. But even with better blades, you're pushing the limit on what it can keep stable in the air. I have the T-motors as well, and they don't provide any appreciable increase in thrust or lifting ability.

Also, that may be the heaviest gimbal I've ever seen fitted to a Phantom :shock:

 

[JKith-Flight]

Re: Violent Shaking after custom mods, PLEASE HELP! (With Pi

Yes, the batteries are mounted the same way, I tried also mounting the batteries below the brackets instead of on top and the same shaking happens.

In desperation I wrapped electrical tape very tightly around the arms of the phantom to add more rigidity, and it flew a bit more stable, but still very shaky. I wonder if they make a Carbon Fiber case for the phantom,...in any case, it's still odd that it shakes since my setup before was 1360grams with the Zenmuse.

Shocking thing is, is that I still have to add the FPV, Telemetry and retractable landing gear :?

Maybe I should put everything on a Tarot XY650 Frame instead,...idk,..I think there is still something wrong. Doesn't seem that 140 grams more would make a huge shake issue.

 

[Gizmo3000]

Re: Violent Shaking after custom mods, PLEASE HELP! (With Pi

What have you done to that poor little Phantom?? :shock:

You could try lowering the gains perhaps.

But definitely consider upgrading to a larger quad if you're looking for longer flight times with that heavy gimbal.

 

[OI Photography]

Re: Violent Shaking after custom mods, PLEASE HELP! (With Pi

Doesn't seem that 140 grams more would make a huge shake issue.

It can, if that pushes you over certain thresholds. When I asked about the batt trays on the other Phantom, I meant whether it was as heavy or not...and when you're already at the edge of how far you want to push a P1 on 8" props, even 140g can make a big difference. That much weight difference can eat well over 2 minutes of flight time as well.

When I first tried those kinds of battery mounts on my P1 with 8" props, I got it to about 1420g before it started getting all squirrely.

have you tried using larger and/or non-CF props, such as the stock self-tightening props from a P2?

 

[JKith-Flight]

Re: Violent Shaking after custom mods, PLEASE HELP! (With Pi

@OI Photography
I have 9" CF Props that i'm going to try. (need to balance them first)
The other phantom running the two batteries was much lighter, didn't have anything on it except an anti-jello mount (no gimbal)

Next step I think is taking off the gimbal (a lot of work) :| and seeing if it will fly correctly to rule out anything structural.

Something did come to mind though,....On 2 of the motor wires, I used a thicker gauge wire (as I had to cut them on the build)
Do you think that would cause strong shaking like this? I want to put up a video so everyone can see the shaking, makes the phantom shell look like it's made out of jello....

 

[OI Photography]

Re: Violent Shaking after custom mods, PLEASE HELP! (With Pi

Next step I think is taking off the gimbal (a lot of work) :| and seeing if it will fly correctly to rule out anything structural.

Good plan, I would start undoing your changes one by one till you find the culprit(s).

I can't think of any way the different gauge cables could cause the problem you're having.

 

[EMCSQUAR]

Re: Violent Shaking after custom mods, PLEASE HELP! (With Pi

I see a number of problems here. First battery configuration -with that and all the gear and if your gains are stock - it's no wonder it shakes. With that configuration besides gains you're going to have to reset your center of gravity settings. (Trust me I know - I have one more fully loaded that yours)

As far as gains settings go - you are going to have to experiment w/them. Each Phantom has it's own signature when optioned out. What works on mine is not neccesarily going to work on yours. So experiment.

Weight is killing your flight time and stability and throwing extra batteries only gains you about 25% flight time if that. P2 props will help but they also need to be "learned". Your stock 8 inch props are nice, smooth for basic Phantom but add weight and they struggle. Adding P2 props will give you more lift but they're an agressive pattern - they also give you more prop wash. Add the prop wash + weight and an increased descent rate due to weight and landings get tricky.

 

[JKith-Flight]

Re: Violent Shaking after custom mods, PLEASE HELP! (With Pi

@EMCSQUAR
How does one change center of gravity on the phantom? I don't think I've heard about that adjustment before.

 

[JKith-Flight]

Re: Violent Shaking after custom mods, PLEASE HELP! (With Pi

OK,...found a solution. Just purchased the FlameWheel 450 Frame. Going to do a frame swap. I'm done trying to make the Phantom shell work. The full build would weigh in at 1720grams, so too much for phantom frame to handle. Hope this doesn't make me a non-phantom pilot! :?

I'll post some pics when i'm done. Going to go for retractable landing gear as well,....might as well take full advantage of the 3-axis gimbal.

Cheers and thanks for your help everyone, it was fast and informative.

 

[Gizmo3000]

Re: Violent Shaking after custom mods, PLEASE HELP! (With Pi

OK,...found a solution. Just purchased the FlameWheel 450 Frame. Going to do a frame swap. I'm done trying to make the Phantom shell work. The full build would weigh in at 1720grams, so too much for phantom frame to handle. Hope this doesn't make me a non-phantom pilot! :?

I'll post some pics when i'm done. Going to go for retractable landing gear as well,....might as well take full advantage of the 3-axis gimbal.

swapping Phantom guts to a F450 isn't as desirable as building one with parts meant for a F450.
you're just going from one "frankensteined" quad to another.

you're going to need a better Tx if you're going to try retracts as well.

 

[JKith-Flight]

Re: Violent Shaking after custom mods, PLEASE HELP! (With Pi

It's not going to be a hack job Gizmo, I'm going to buy the parts needed. Example GPS module new ESC's, etc. And my TX is plenty capable, it's a Futaba TF8 with 14 channels.

 

[Gizmo3000]

Re: Violent Shaking after custom mods, PLEASE HELP! (With Pi

It's not going to be a hack job Gizmo, I'm going to buy the parts needed. Example GPS module new ESC's, etc. And my TX is plenty capable, it's a Futaba TF8 with 14 channels.

In that case, why bother in the first place, Keep your Phantom around and intact as backup or fun flying, and then buy all new parts for your 450.

the only thing you can rally pull from the Phantom is the NAZA, and the motors (which you might have to solder bullet connectors to to work with certain ESC's.

 

[JKith-Flight]

Re: Violent Shaking after custom mods, PLEASE HELP! (With Pi

Good point, but 1: I already have a backup phantom and 2: I will save hundreds of dollars this way. Then I'll sell the leftover parts too.