Hello Everyone,
So I finally received my APM 2.6 + accessories. As it's been almost a month since I ordered it so I had a lot of time to consider how I was going to dampen the vibrations. Below in the photos is my solution (not sure if it works yet, as I haven't tried to fly).
1. The Final Product
2. Adding the vibration dampening (silicon fuel tube) to the screws.
3. All the silicon tube has been added (still some thread showing so it makes it through the frame)
4. The view from the bottom. The holes used are already present on the TBS Disco bottom board.
5. The side profile.
6. The APM upside down with 3M double sided tape, moongel and double sided tape.
Explanation:
- I cut a piece of wafer board just a bit wider then the APM, drilled four holes in it which line up with pre-made holes in the bottom of the TBS Discovery frame.
- I placed 3x10mm screws in the holes then flipped the wafer board upside down.
- I then placed silicon fuel tube on the thread of the screws then cut about 60% of the tube off the screw (leaving enough thread at the top to get through the frame and attach by nut to the bottom.)
- I added the nut to the bottom of the board, with some threadlock and just enough pressure so that it was firm but there was still flex if I pushed down on top the board towards the frame.
- I then attached double sided tape to my APM, followed by Moongel then another square of double sided tape. Then placed that on top of the newly mounted wafer board.
- Lastly, I secured the APM to the wafer board with two elastic bands.
So in review the dampening is:
APM 2.6
Double Sided Tape (3M)
Moongel
Double Sided Tape (3M)
Mounting Plate
Silicon Fuel Tube
Frame
I realize that it's not the prettiest setup but I'm pretty confident that it'll do the job. I'd wait to see what the end result is (if it works or not) but I'm too proud of it to wait...
Shout out to Dany (www.canadadrones.com) for his suggestions/help on this topic and Dennis Baldwin (YouTube) for this videos on vibration dampening.
Comments
@Rob, sorry i was not aiming my comment at you, i know you have always answered my questions and helped me out. Im really keen to learn if its possible to better tune the machine by analysing the logs and left questions about this all over this forum and no replies. I feel there must be a more accurate method and tying your machine to 2 chairs........
Tony
Thanks Michael...I used standard double-sided servo tape for the APM (the blue roll which is not the super sticky "forever" type) and the radio. I tried the Moongel but never found a good method, short of strapping, to make the APM secure enough.
Here's a link Dampening Blog to a blog with more information on the build. My other interest is woodworking so I built a few quad frames from wood (I got tired of crashing and breaking the plastic ones!) and I believe the wood arms help dampen the motor vibrations. It's not very elegant but it sure flies well and is quite tough.
Post some pictures when you're finished...I'd like to see it!
Mark I ordered those same bobbins last week from GetFPV.com... I'm hoping to achieve the same result you have there. Very nice work. Do you have the APM 3M taped to the board or is there some Zeal/Moongel in between?
I was considering using the Bobbins + Zeal for maximum effect but judging by your results that may be overkill.
Well then, some Zeal and the RV anti-vibe mount really did the trick. Granted, this is just a 9 minute hover test but that's some low vibration!
http://i.imgur.com/glr4KTm.png
Here is a crappy phone pic of how its setup. I still haven't received my APM case so i'll have to redo it all once that arrives.
http://imgur.com/sPVGHq8
Yes, the APM is still a bare board. My case is on its way. I'm sure its because of the setup as I know this Zeal is good stuff.
I'll have another go at it tonight and ensure the wires going to the APM have some slack (not sure why I didn't think about that before). If only my case would get here sooner!
Hi Chris, I am sorry to hear your bad results, first time I have heard such a response from using Zeal.
Definitely A Velcro strap with soft foam between it and the APM will help, but your results suggest something else is causing the problem.
Just a few quick thoughts.
Do you have at least a bit of a strain relief loop in all wires connected to APM so they are free to flex?
Is there anywhere where the APM can come in contact with the undamped frame?
Vibrating against frame can make accels much worse.
Finally are you sing bare board or APM in a case?
If you are using double stick Zeal direct on PC board, all the devices and solder bumps can cause small gaps that can actually increase vibration so if bare PC board, better to hard mount to a FG intermediate plate and then use Zeal between intermediate plate and frame.
Please put in a few photos of your setup showing Zeal and rest of mounting and I will see If I can spot anything.
Something is definitely funny.
With the APM in a case, no possibility of APM touching frame or frame parts and a bit of light retention this definitely should work way better than double sided foam tape not way worse.
So, I got my Zeal today. I cut 4 3/4" squares for my APM and pulled off the nasty 3M double-sided foam tape that held it on. Went for a flight and well... It couldn't hold altitude to save its life. It was almost scary!
Got back inside and analyzed the logs. WAY worse than with the 3M tape alone. + and - 30 on the Z axis at times and even my within spec X and Y's were all over the place. Now, the APM was ONLY held on to the top of my F450's (Genuine DJI) frame by the Zeal itself. I'm thinking I should have used a (couple?) velcro straps to hold it down and push it against the Zeal a bit.
My RV Mount should be here tomorrow I hope so first thing I'll try is just using some velcro straps to hold the APM down on the Zeal. Then I'll try the APM on Zeal on RV Mount.
Either way, my altitude hold wasn't even bad with just 3M foam tape!
Very nice results.
Michael...great result! Is that with the original setup you proposed in your post?
I've had good luck as well with anti-vibration bobbins mounting a bit larger electronic platform. I don't use gel but my bobbins don't have a screw through the middle, plus they were a bit pricy...about $20. Here's my result, similar to yours:
Here's a picture of the (orange) bobbins holding up the platform (close up lens distorts the acrylic...it really is straight!); I believe the extra mass of the platform, the electronics, and cover, help with the dampening:
And here's the result....
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