Vibration Isolating the FC - does this look any good?

[cgcrute]

I used a couple of M3 bolts and spliced them into a ear plug. The glue caused the ear buds to stiffen up a bit but it';s still squishy.

Does this look sufficient to do the job?

[teslahed]

That looks very good. You may find it works TOO well though - you can have too much vibration damping and the flight controller starts to ';wallow';.

So if it looks like it should work but flies terribly - that is probably the reason why. You have to experiment to be sure. Hopefully it will be just right for you

[cgcrute]

That looks very good. You may find it works TOO well though - you can have too much vibration damping and the flight controller starts to ';wallow';.

The foam between the bolt heads has stiffened up due to the glue so I don';t think it will wallow too badly.

Is the damping definitely required? I';d like to get the board inside the frame but there isn';t the clearance with the power distribution board. It';s the same frame as in this thread http://www.multi-rotor.co.uk/index.php?topic=2879.15 and they are getting good results without it.

[dazza22]

hi
I have 3 multicopters all running APM2.5 . after trying different method .I now  use this foam http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=26457  it works great just a piece the size of the FC with double side tape to the FC and then double taped to the frame .
my vibration level are very low !
worth a try

cheers

[cgcrute]

hi
I have 3 multicopters all running APM2.5 . after trying different method .I now  use this foam http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=26457  it works great just a piece the size of the FC with double side tape to the FC and then double taped to the frame .

Thanks, I';ve decided to rebuild with the board inside using a scalled down version of my 1st effort - single bolt damped top a bit with bits of earplug. I';ll add some of that foam to my next HK order and give it a whirl too!

[Biffa]

Since I started flying multi rotors I have used one piece of double sided sticky foam and stuck the various boards down with that.

IMO you can spend too much time and effort trying to dampen vibes from the board which is unnecessary. I have never had any issues, you find the same thing being done with the gyros on model helicopters.

The foam I have used is the Hobby King ';peel n stick'; stuff.

[dazza22]

Since I started flying multi rotors I have used one piece of double sided sticky foam and stuck the various boards down with that.

IMO you can spend too much time and effort trying to dampen vibes from the board which is unnecessary. I have never had any issues, you find the same thing being done with the gyros on model helicopters.

The foam I have used is the Hobby King ';peel n stick'; stuff.

I do agree with you , but APM2.5 running the 3.01 software does need it a little thought  put in  setting it up for vibration  reduction , I feel .

cheers

[kogashuko]

Hmmm, maybe that is why I had problems in the past with a few things... mine is bolted directly to the board with two metal bolts!

[Hands0n]

I';d say from very recent experience that particularly with Arducopter 3.0.x and above that you must solve the root cause of vibration as well as dampen the physical connection between the air frame and the APM 2.5 or Crius AIOP flight controller board.

A direct hard connection is likely to cause difficulties. ::)

Sent from my C6603 using Tapatalk 4

[dazza22]

I';d say from very recent experience that particularly with Arducopter 3.0.x and above that you must solve the root cause of vibration as well as dampen the physical connection between the air frame and the APM 2.5 or Crius AIOP flight controller board.

A direct hard connection is likely to cause difficulties. ::)

Sent from my C6603 using Tapatalk 4

totally agree....

[Biffa]

I had no problems at all using my Crius board just stuck down with foam tape on either frame I used it with, and have no troubles either with my kk boards using the same method on four separate builds.

I am aware from what I have read the APM boards can be a little fussy though and perhaps the v1 Crius is less particular about mounting that the v2 boards?

Personally I would rather try an easy option first before going to such elaborate lengths on something that may not cause you a problem, if that makes sense.

[Hands0n]

Personally I would rather try an easy option first before going to such elaborate lengths on something that may not cause you a problem, if that makes sense.

That cost me my first fly away of £250+ work of kit, never to be seen again     

I thought, post build, to give it a quick try in the back garden, 11pm at night (okay, fair enough, that was asking for trouble).

It isn';t the APM board as much as v3.0.x of the Arducopter firmware.   It uses the ACC as part of its algorithm to stabilise in the various modes.  As such, vibration has a much bigger impact on the algorithms and may cause unpredictable behaviour [I claim that as 2013';s biggest understatement of the year  ].

There is a more than fair chance that those same algorithms have found their way into MPNG3.x.  So AIOP and any FC that is capable of using MPNG are likely to be at the same risk.

Arducopter wiki has a page dedicated to sorting out the vibes - with log graphs of the "acceptable" limits.

The biggest cause of vibration in my case were the propellers - both for the blades and the hubs which were massively out.

What I am saying is to please be aware of the risk.

[cgcrute]

That cost me my first fly away of £250+ work of kit, never to be seen again 

Funny you should say that, at roughly the time you typed that my Quad flew away, changed direction a few times then finally ditched itself into the playing field at work. Props all snapped, no obvious other damage until further inspection. It was still madly trying to bury itself into the ground when I finally reached it.

I have no idea why it did this, I was tuning PIDs and it was going quite well. Is there sufficient info out there to diagnose these things or should I make a post to canvas for ideas?

[Hands0n]

I see from your sig that you';re flying a Crius AIOP - would that be with MegaPirateNG or MultiWii code?

There are some good PID tuning guides on this forum. Probably worth a read of them first, see if they work for you.  The advice is generally going to be the same.  Get rid of any vibration sources, tune P first, then D followed by I (thats what I found for APM).  If possible use a spare knob/channel on the TX to help trim while in flight if your flight controller software allows it (Arducopter, not sure about MegaPirateNG).  Small changes and only one change at a time.

[cgcrute]

I see from your sig that you';re flying a Crius AIOP - would that be with MegaPirateNG or MultiWii code?

MegaPirateNG, is MultiWii more stable that the other?

I';ve read the guides on PIDs and was adjusting them. Things had got considerably more stable than when I started but then this happened out of the blue!

[Hands0n]

My understanding is that MegaPirateNG is identical to Arducopter (APM 2.5).  In that respect it is much more configurable, which translates into requiring more effort.

MultiWii is not any more stable, in fact likely to be less so than MegaPirateNG. But it is simpler to set up for sure.

When adjusting the PID you do have to go slowly, one particular change at a time, then evaluate it, before doing the next thing. Essentially it is a matter of adjusting each to introduce stability.  The guides on this forum are splendid in that respect.

[teslahed]

In terms of the stability of megapirate and multiwii;

When tuned it';s arguable that megapirate is more stable. It has a more comprehensive auto-level with better loiter and other GPS modes with better functionality, including waypoints.

I';ve never seen megapirate setup to fly gyros only in a way that';s controllable or fun in the way that you can easily achive with multiwii. If you just care about flying with the best possible connection / response from the quadcopter in gyros only mode - multiwii is untouchable.

So there are different kinds of ';stability'; - megapirate wins most but for pure flight multiwii is much better in my experience.