I Have inserted the starting pass at a much needed section on Vibration Control in the ArduCopter Wiki and would very much like feedback for corrections or additions from you all.
This is the close coupled mount that I use on my little F330 Flamewheel.
To achieve this plus and minus one tenth G vibration dampening.
In any case, please review the Vibration Control Wiki section under Assembly and give me some (constructive) feedback.
In my experience you do not need additional retention, if you do it right, they lock tide in. And you can adjust the amount of dampening by adjusting the distance between the two plates, just pulling the ear plugs more or less through.
I managed to fit the APM 2.5 and the DX8 receiver into one box, keeps the wiring down and adds weight to the box which is better for vibration dampening too.
This is a graph showing vibration of a T-Rex600 in a hover with some horizontal and vertical movements.
That is one of the most novel solutions I have seen yet and I've got to say, some of the high tech ear plugs should be just about the right durometer and have excellent wide frequency dampening properties.
Possibly some sort of additional retention mechanism might be desirable but I suppose that depends on the specific ear plug.
I would really like to see some comparative logs from anybody using this technique with an APM.
Ear plugs, are so great for vibration damping, and you need not to glue them on, just pull them through a 5mm hole, and they lock them self in.
Prior to our incorporating inertial navigation, vibration wasn't a critical issue, but now it is and the Accelerometer really requires a tailor made solution.
Our needs are very specific and we really need to eliminate the vibration appropriately
You are right in thinking our vibration reduction solution needs to be short coupled however it also needs to be tailor made for just the mass and dampening requirements of the flight control board or it becomes considerably less effective. Too much is just as bad as too little.
The vibration is almost entirely caused by the motor / prop units at flying speed.
Although propeller balancing is the primary way of reducing vibration to the frame it is not sufficient by itself for our needs whereas, generally speaking vibration dampening the flight control board is.
That is why vibration control of the flight control board is first.
And the reason propeller balancing is not covered here is because it is covered in virtually every article on setting up RC planes.
Motor balancing is generally a smaller problem but this is one quick solution that is was pretty clever.
Tightly fasten a tie wrap around a motor, trim off the extended tab and spin it up (with no prop), try multiple times each time turning the tie wrap on the motor housing a bit until the vibration reduces or goes away.
When you locate the spot where there is the least vibration you can mark the spot directly under the clasp of the tie-wrap with a felt pen.
Then add a small dot of hot glue gun glue where the Tie-Wrap clasp was and increase the glue a bit at a time till the vibration is minimized.
If you put too much glue on it can be removed with an X-acto knife.
Simple but effective.
I am putting that in the Wiki. - Correction - I have put it in the Wiki!
And Jason, your system certainly should be superior.
Please submit the procedure to this site when you've done it and I will be happy to publish it to the Wiki also.
Jason....I think that would be the best solution. All the hardware are already in place for all who own an APM. I assume it should work for the props too once to motors are balanced.
I was thinking of writing a simple motor balancing CLI test. Basically it would run a particular motor at certain speeds for 5 seconds then spit out a score. Move your tape around the motor until the score drops and you've got a balanced motor. It would use the accels from the APM so it should be fairly accurate and practical since you wouldn't need to unmount your motors. Just your props.
1) Consider putting prop balancing first along with details on how to do it. That's a pretty simple way to reduce a lot of vibration.
2) What is a good motor balance procedure? I am not familiar with this.
Does anyone have good theories on where most of the vibration comes from to begin with? Props? Motors? Turbulence? Natural frequency of various frames? Frame material might play a large part in vibration.
There was recently a posting that talked about how we are overdoing the amount of dampening material. Or better yet; not taking full potential of thier properties.
I think we need something simple, like we coat the inside of the APM2.5+ Case with vibration dampening material such as this...
Silent Running stops unwanted noise and vibration.
Thereby not needing external vibration dampening; or mountings that can lead to loss of "visibility" to the sensors.
Hi Again Josh,
I Googled Moon Gel and definitely would like to know your results with it, looks like a really exotic substance, and should be interesting.