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.
Thank You,
Gary McCray
Comments
Thomas, thanks for that link at digikey! That's fantastic! I wanted to get shoulder screws like that, but they are ridonculously expensive at McMaster.
One issue though: The steel screws will cause mag interference on the board if you are using the build in mag... I use the blue grommets with nylon screws, nuts and washers.
Great and this link above would be good to add also.
http://www.mcmaster.com/#vibration-damping-grommets/=lk3num
Those are nice motor mounts Dany Try this link: http://www.mcmaster.com/#vibration-damping-grommets/=ljy64x
And look at part numbers 9311k64 and 9311k35, you want fast recovery and these are the lightest ones, still a little heavy, but probably if used with a secondary Alpha gel, silicone or Sorbothane foam pad under the flight control board would achieve decent results and should be less than 0.1 G vibration amplitude possibly even < 0.05 G.
Hi F11, those are directly linked on the Vibration Control section of the Arducopter,
I think some people (not here) are trying to directly translate their vibration experience with helicopters to multicopters, and thus the proliferation of "that doesn't work" comments in some places. Those with more experience, or those who played around with it, can probably say it's not necessarily the same at all, depends what you're trying to do.
What do you think of this (I obtusely referred to it yesterday): The motor is the vibration source. Take off the props and disconnect the motors'/ESC's power except for one of them. Vary the speed and put your finger lightly on an arm. Feel the vibration amplitude change as you move your finger along the length of the arm. Now do the same thing with all motors running. Do you feel (or better, measure) any "cancelling out" (from multiple vibration sources) of vibration at some points on the arms? Tune vibration via arm length to minimize it at the APM mounting spot? I wouldn't be surprised if some makers have done something like that. I found that by stuffing light stuff (foam etc.) in the arm I could make it behave differently, even plugging the motor end (I originally did it to keep dirt out) changes it. I don't know if this leads anywhere useful, but besides what I can feel/measure with this one sample, having the vibration source on the end of a hollow arm, the amount of vibration just has to be affected by arm length (besides all the other physical attributes of any given arm type). I think there's something here, but just thinking about thinking about it makes me run for a brew...
well these are quite similar to the ones we sell from jDrones...
http://www.canadadrones.com/Motor-Multi-Mount-single-set-p/jd-ac-mo...
they are great, they even work on 3DR arms with a bit of creativity and longer screw! :)
They will reduce down a lot of vibration for sure.
And for the "usual" rubber stand off with screw we have these, I use/sell them mostly for camera gimball isolation, not sure how good they will work for the little weight of the APM...
http://www.canadadrones.com/Anti-Vibration-spacer-M3-x-8mm-p/vib-m3...
I will give the McMaster stuff a try... any product in particular that you think will be good? (link? )
Dany
Anyone tried these?
http://www.shop.aglhobbiesllc.com/Motor-Mounts/Universal-Anti-Vibra...
Jason, great idea about the motor test!
Thank you for the reference to McMaster Carr Robert, I think I can order from them via my wife's jewelry business after looking at their site.
I will definitely try some of those and yes I did find some at Digikey from KeyStone as well.
I really wish I could get some of the 3M EAR Shear Grommets (Or Lord Micro Mounts for that matter), but that looks like having to go through the national sales rep and I'm not quite ready for that yet.
However, I am trying to design a isolated (grommeted or shock mounted) plate with secondary dampening of the flight controller board itself, that we can all use, so I might try the old samples ploy.
They sure don't make it easy to try out a bunch of different options.
Thanks guys. I am still experimenting, I still gotta try those E-A-R things on the APM board itself too. Though I much prefer the idea of screws/standoffs/grommets etc. so everything is tied down if possible (my preference != good necessarily).
And dammit, I was looking for isolation grommets on the Digi-Key site just last week and came up blank...especially Keystone since I buy a lot of their other hardware too. Maybe I'm going crazy (too late...what with the SteadiDrone thing I missed too).
Craig, yes, I'm lucky to be able to order through work. It is a PITA that McMaster won't do private sales to customers.
One thing I have found however, is that will ship to my house, and charge my personal credit card, even if I am using my work account. So it's almost transparent from my work, though they do mail them a receipt.
If you want to try some of these grommets out, I can mail some to you.
Dany, that's a good idea. These grommets are cheap as chips, so it wouldn't take much for you to be able to offer them.
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