Vibration Dampening Methods - Share Yours

[Snarls]

So far vibration dampening has been the number one enemy for me in this hobby. I have built quads that fly amazing (to me at least), but the part that always gets me is when it's time to isolate the camera from vibrations. I want to know what others are using as DIY vibration dampeners. I have already balanced the motors and props and tuned the quad so this is all about isolating a camera platform.

Currently I am using rubber balance balls in combination with a steel cable running through them. It works pretty good, but there is still a hint of vibration in my video and it is unreliable because some days are worse than others (I have video if requested). One of my main problems is balancing between too loose and too rigid of a mounting.



Some of the options I've heard of are:
-Vibration dampening balls
-Wire rope
-Stiff wire (David's Tricopter)
-Moongel
-Nothing

 

[William A]

Servo mount tape is all I use.

And sometimes not even that.

 

[William A]

OT, clear plastic ?

 

[Snarls]

OT, clear plastic ?

It's plexiglass, sometimes double thick. Its stronger than the plywood used in the frame and its the only thing I have that can be bent into angles.

 

[William A]

Use to get carried away with my FC mounts also.
NOTE:::: DO NOT copy this mount for your FC.
(crazy/random oscillations)

Although, this might work for a cam. Up size the rubbers a bit.

 

[William A]

Hmmmmm....

 

[Snarls]

Thanks for the suggestions William A. I am trying to get a setup with the least weight and profile. Right now I am going back and trying wire ropes again.

 

[PHugger]

I'm going to try some moon gel under my Mobius. I have no opinions yet, just a few endorsements about how well it worked. We'll see. At the very least it will keep the camera from sliding out.
The Fortis Tricopter I'm building uses Tygon tubing to isolate the camera platform. No opinions on that yet either, but I'm thinking the added mass of the battery attached to the platform is the real trick.
Some pictures of the Fortis are here -
http://forum.flitetest.com/showthread.php?15051-First-Multirotor-Build-–-Fortis-Titan-Tricopter&p=162990&viewfull=1#post162990




Best regards,
PCH

 

[earthsciteach]

Vibration isolation/dampening is very tricky for multi rotors. We are dealing with very high frequency, very low displacement vibrations. While these are the easiest kind of vibrations to attenuate in industrial applications, we are hampered by the need to keep weight as light as possible.

Isolating, say an industrial pump is easy. The bolts that hold the pump in place are sunk into the concrete slab. Those sleeve through spring and rubber isolators, which allow the massive steel frame of the pump to vibrate away without that energy being transferred to the floor of the building. Piece of cake.

We have no significant mass to act as an "anchor." So, even small displacement vibrations pass the energy throughout the entire multi-rotor. And, we compound that with multiple motors, each vibrating at some frequency, reinforcing each other's vibrations or canceling out, and always changing.

I've been working on isolating the vibrations at the source - the motor mounts. This is a very difficult prospect. A fairly "soft" material is needed to absorb the energy, but soft materials allow the motors to flex and torque. Its a self-defeating proposition. But, I'm still working on it!

For your camera, add mass to the plate the camera is mounted upon. Hopefully you can find a nice compromise so that the mass added is not too much of an impact on flight times. The mass will add inertia to the camera mounting plate. That will help a good bit.

 

[Snarls]

Ok, I went ahead and built a low profile wire isolator to replace the rubber dampening balls. Because it is so short in height the wires are very stiff and there is hardly any play except in the forward/back direction.




As you can see in picture 2, I put a rubber band near the roll motor to constrain the play in the forward direction. I later removed it because I think it does more damage than good. I took it out today for a test run in my yard newly covered with 6 inches of snow. This time instead of a rubber band there is a rubber vibration ball between the frame and roll motor. Unfortunately there was what appears to be jello, but there are times when the video is smooth. This makes me wonder if the issue is now a tuning problem.

I then took the quad out at dusk to see if the jello was real. The shutter speed is slower in low light so any previous jello appears as fuzzy video instead. This time nothing was constraining the play in the forward/back direction. It is pure wire isolator. I had a 1300 mAh onboard to power the gimbal instead of a 500 mAh and as a result the quad became sluggish.

Weirdly the video is almost perfectly smooth. I'm thinking the extra weight may have led me to a better tuned quad. Overall I do not know what the exact issue is during the day time. It could still be vibrations, gimbal tuning, quad tuning, or a combination of all.