I did Manfred Dickgiesser foam ear plug mounting for my 450 flamewheel quad with APM 2.5 running v2.9.1 and MPU6K_FILTER = 20. APM is mounted on a thin aluminum plate with double-sided foam tape. A ¼" thick plate of Polycarbonate plastic is taped to the bottom of the aluminum plate between the orange foam ear plugs to give added mass to the mounting assembly. The ear plugs are glued to the top plate of the quad frame with Goop. Seems to work well for controlling XYZ Accel's. Z data value analysis in an Excel spreadsheet shows a Standard Deviation of 2.02 for continuous 2300 sample points.
The ear plugs survived their first crash. I accidently switched into RTL without knowing and flew it into the ground.
I would have never thought to use foam ear plugs for vibration mounting. What a cool idea...
Comments
2.5 mm silicone washers (8 for $1) - perhaps for the motors? And/or the flight controller and/or camera...
http://www.quietpcusa.com/Acousti-Anti-Vibration-Silicone-Washers-8...
Hi all,
Steve, the tape definitely looks interesting, probably urethane foam.
I'd suggest you just use 4 small pads of it under the corners rather than running it under the whole APM though since it is so light (and definitely not a camper shell).
And Greg, sounds great, I would very much like to see your accel graphs from a stable hover and good choice using aluminum, won't mess up the magnetometer.
I think the Zeal and the Sorbothane might be very effectively incorporated in a 2 part system since they have such different characteristics.
I would suggest only using fairly light pressure with the rubber band retention system.
Twenty percent compression of the Sorbothane is the recommended amount and 30 duro is quite soft so that isn't much.
Gary,
Those Sorbothane bumps do look like a good idea. I already have some Kyosho Zeal sheet that I plan to cut into 1/2" diameter circles. Maybe I will order some bumps to make a comparison. I am not close to flying yet but it will be interesting to do some tests on vibration isolation using the various ideas. I plan to start with the glued on ear plugs through holes in a mounting plate (as shown above) but with a thicker aluminum plate to get the added mass with the APM mounted on the plate with either the Zeal or Sorbothane pads and with rubber bands compressing the APM down.
I was thinking about using ear plugs and then I came across some foam at Lowes used for mounting truck camper caps. Super soft, comes on a long roll for about $10. It's single sided adhesive so I added some super glue like 3M foam tape to each side before mounting the case. Also use it for my GoPro on the TBS Discovery. You may be able to see from the pics it actually keeps an imprint of my finger print for a few seconds before it slowly fills out.
Hi Greg,
I got a small batch of adhesive back 1/2" 30 Durometer Sorbothane "Bumps" (Hemispheres) from Amazon (Isolate-It) to use for just this purpose.
they are quite soft and I am not sure whether I am going to use 4 or 6 of them under my flight control board on top of my already O-ring suspended intermediate plate.
The advantage to the hemisphere is that it makes the damping a bit more progressive than a simple cylinder or cube.
So far 30 duro Sorbothane looks like it ought to be great stuff though.
I notice in the instructions for using Sorbothane on Amazon that they recommend using several small circles rather than larger squares of material. They claim that a concentric bulge using circular material provides better isolation than a square pieces of material. Any evidence that circular pieces would make any difference for APM isolation?
I personally wouldn’t glue the earplugs, if the glue stops to stick, then you in trouble. And you never know how glues interact with certain materials.
I use the ones made out of soft memory foam.
Hi Chester,
Good point about cold and ear plugs.
Great results though.
And nice looking Discovery
One thing that I notice hasn't been addressed much about this solution is that there are, in fact a lot of different earplug materials, from straight poly foam to much more durable and damping effective urethane and silicone foams and gels.
One of the things we need to do is test a variety of them and determine which ones actually work best for this use.
Hello,
I also used ear plugs for vibration isolation. But I still down like results. I noticed that ear plugs get hard in cold weather condition. Indoors (+25..+27 C) they a very soft and have to work very well, but when i go outside (-5.. 0C) they become harder and looks like passing through vibration. Here I my setup and some raw log graph.
PS: Sorry for my bad English.
Hi Jim,
I just added a link to your BLOG on the Vibration Control section of the Arducopter Wiki under Manfred's entry.
This is a very easy to implement solution and I am definitely going to try one with this style too.
If you are interested in improving even more, just a few things you might consider trying.
Instead of the foam tape under the APM enclosure, you might try a 1/2" square of Align or Kyosho Zeal gel under each corner and then hold the box down onto the top plate with one or 2 rubber bands rather than a zip tie (to allow elastic springiness).
From what I have seen, this sort of 2 part solution can allow the damping characteristics of one medium to complement another one and result in superior damping.
Just a thought, but if you do I would very much like to know your actual results.
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