High Z vibrations but no clipping - 30 inch Quadcopter sys

ArduCopter Copter 4.6
1

Hi everyone,

I’m currently tuning a 30-inch quad and experiencing higher-than-expected vibration levels, especially during movement. I would appreciate some guidance before proceeding with AutoTune.

Hardware Setup

  • 30" foldable quad airframe
  • Battery: 12S
  • T-Motor Flame ESCs
  • Flight Controller: Cube Orange Plus
  • Propellers: T-Motor 30x13 propellers.

So far, I have followed the official ArduPilot tuning instructions, configured harmonic notch filtering, and completed the initial manual tuning. After this initial tuning, the quad flies stable with no error messages or EKF issues, and overall flight performance appears normal.

However, from log analysis, Vibe X and Y are around 30 m/s², while Vibe Z is close to 50 m/s², with vibrations increasing noticeably during movement. Since AutoTune requires lower vibration levels, I would like to reduce these further before proceeding.

For troubleshooting, I tested both soft-mounted and hard-mounted flight controller setups. Hard mounting resulted in significantly worse vibration readings, while soft mounting showed no meaningful improvement.

Flight logs:

Soft Mounting

Hard Mounting

Are these vibration levels acceptable for a 30” prop setup, or should they be reduced further before Auto Tune?

Could this be related to large prop balancing, frame resonance, ESC timing/PWM frequency?

Or is there any other way to resolve this. Please guide in this matter.

Thanks in advance,

Regards.

2

Large drone experience a lot more vibrations than what ~5” does. Here are some insights I learned over 2025 developing a 30” drone.

Frame

The stiffness and modal frequencies of your frame matters alot. If your frame isn’t stiff enough, low-frequency vibration will propagate from the motors through the arms and into the body/FC.

It is worth the time to ensure a very good mechanical frame

Props

Using high-quality props such as T-motor props helps alot. Using non balanced props will lead to alot more vibbrations. If price isn’t a concern the T motor full carbon fibre props are very good.

Free Fly has an interesting vibration dampening system on the propeller mount that reduces vibrations a ton. They also do dynamic balancing inhouse. Look at their videos on youtube, might not be achievable on a hobby level.

ESCs

ESCs matter alot more than most people think.

For larger drones, the most common protocol is PWM with no feedback. This is flyable but I was never able to achieve the level of stability and performance from this setup. I used T-Motor Flame ESCs 60A initialyl but had to look elsewhere.

Using ESCs with fast throttle response, telemetry feedback is very important if you want a stable and performant drone. With the telemetry feedback, you can run dynamic notch filters which will improve flight performance a lot since you can increase your gyro low pass filters and hence make a tighter tune. I am not sure what you ment with harmonic notch filters when you run T-Motor ESCs, since they do not feature rpm feedback. What did you mean? (statik notches?) @1afridi

I can personally recommend APD 120F3[X]v2, they have very good throttle response, a good price and have DSHOT. Make sure to think alot about wiring and length of cables because DSHOT is intended to only run short distances. Twisted pair cable with shielding is almost a must over 10-20cm.

Vibration mounting

Only after addressing mechanical fixes like frame stiffness should vibration dampeners be used.

I’ve tried about 10 different models. The best vibration dampeners like “Alpha Gel” can get 50m/s^2 to go to 2-4m/s^2, but they have drawbacks. All vibration mounts have their own resonances and low pass filtering characteristics. So going for too much dampening will make the drone suffer elsewhere, you need to find a middle ground.

There is also the dilemma, GYRO wants fast unfiltered data, while the accelerometer wants low noise and can handle more delay.

The best I found in terms of price, just enough dampening are these: Tarot - Gimbal Anti Vibration Damping Ball - Small - 3PC - TL10A04 - Multirotor from 3DXR UK

Others I’ve tried:

  • Alpha Gel S bushings
  • Alpha Gel Theta - B dampeners
  • Moon gel
  • sorbothane foam
  • FPV style bushings

Firmware settings

You can get away with a lot of acceleration filtering, I’m running a cutoff at 10Hz for the accelerometer to combat the harsh vibbrations.

3 Likes
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And on such a big expensive and dangerous vehicles you must methodically configure the parameters to make sure you do not forget stuff

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Yes of course. But since he is already up flying with the drone I have assumed setup was completed and was mostly looking for insights, tips on large drone vibration problems.

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6

Curious about how the different gels you tried compare.

Currently trying to minize vibrations on 15” hexacopter running matek h743 slim v4 on normal m3 bolts with gummies, but not getting good performance. The frame is known to be good, since I had minimal vibrations on f405 wing softmounted on a foam “plate”, trying to get a good result with a higher performance/more appropriate flight controller now.

7

This forum is full of drones that fly until they suddenly don’t anymore.

Flying and flying safely and reliably are two different things. This forum is a proof of that.

What is common to all those “it flew fine before” drones? Missconfiguration and/or bad hardware.

2 Likes
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What air frame have you used? Off the shelf one or custom?

Damping grease made a big difference for me: Good result from using damping grease (VIBE graph included)

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9

Have you read an article from some manufacturers on identifying potential sources of vibrations?

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Hello everyone,

Thank you all for your detailed responses and valuable insights.

Apologies for the delayed reply — I was unwell over the past week and wasn’t able to respond sooner. I’m feeling much better now and will go through each of your suggestions carefully and reply accordingly.

I truly appreciate your patience and the time you’ve taken to help. Hopefully, with your guidance, I’ll be able to resolve the vibration issues soon.

Thank you again.

Regards,

1 Like
11

You have valid RPM data with CAN, why you bother with Throttle filtering? It won’t fix your Acc vibrations but better filtering leads to tighter tune that can help indirectly.
What damping platform you use? It’s damping different axes in different way, maybe it can be improved. Also photos of craft itself and arms mount / folding points can be useful.

2 Likes
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HI @RCX749 , I am using a off the shelf frame. It is a monocoque airframe with foldable arms. I will share the pictures below.

13

These are the first Flame ESCs I’ve used that provide RPM feedback over CAN, so I was initially a bit hesitant about fully relying on the telemetry. However, you’re right — I’ll switch to RPM-based notch filtering as the primary method and review the filtering setup accordingly.

For mounting, I’m using the damping platform provided with the frame for the Cube Orange Plus. The airframe is a monocoque design with carbon fibre tube arms.

Airframe / Mounting Pictures

14

Thanks for the reminder.

I’ve generally configured my copters manually by following the official ArduCopter tuning documentation.

To semi-automate the setup and to ensure that I dont miss any steps, I’ve started using the Methodic Configurator. At the moment, I’m applying it on a smaller FPV platform to gain familiarity, and once comfortable, I plan to use it for the larger 30” system as well.

Appreciate the continued guidance

1 Like
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Please provide a link to the Flame ESCs which has CAN and telemetry (rpm) feedback. I’ve never seen T motor that support UAVCAN and telemetry

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That’s probably V series V Series UAV/Drone ESCs | T-Motor Store

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Such kind of mount probably have more rigidity in Y axis because of construction, not clear how dumping is implemented, is there any gums?